阅读说明：本技术 环状化合物、锂离子二次电池用负极以及锂离子二次电池 (Cyclic compound, negative electrode for lithium ion secondary battery, and lithium ion secondary battery ) 是由 浅川雄一郎 上坂进一 安托尼·拉弗勒-兰伯特 卡里姆·佐格希布 于 2018-04-27 设计创作，主要内容包括：锂离子二次电池具备正极、负极和电解液,该负极包含环状化合物,并且该环状化合物包含第一环状化合物、第二环状化合物、第三环状化合物、第四环状化合物、第五环状化合物以及第六环状化合物中的至少一种。(The lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte, wherein the negative electrode includes a cyclic compound, and the cyclic compound includes at least one of a first cyclic compound, a second cyclic compound, a third cyclic compound, a fourth cyclic compound, a fifth cyclic compound, and a sixth cyclic compound.)

1. A lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolyte, wherein the negative electrode comprises a cyclic compound, and the cyclic compound comprises at least one of a first cyclic compound represented by formula (1), a second cyclic compound represented by formula (2), a third cyclic compound represented by formula (3), a fourth cyclic compound represented by formula (4), a fifth cyclic compound represented by formula (5) and a sixth cyclic compound represented by formula (6),

wherein X1 to X16 are each independently any one of oxy-O-and imino-NH-, and R1 to R6 are each independently ethylene-CH₂-CH₂And any one of dicarbonyl-C (═ O) -, M1 to M26 are each a metal element, Y1 to Y26 are each a halogen element, and n1 to n26 are each an integer.

2. The lithium-ion secondary battery according to claim 1,

m1 to M26 each represent any one of tin Sn, titanium Ti, silicon Si, copper Cu, manganese Mn, iron Fe, niobium Nb, nickel Ni, cobalt Co, aluminum Al, and zirconium Zr.

3. The lithium-ion secondary battery according to claim 1 or 2,

Y1-Y26 are respectively any one of F, Cl, Br and I.

4. The lithium-ion secondary battery according to any one of claims 1 to 3,

all of X1 to X8 are oxy or imino,

all of X9 to X16 are oxy or imino.

5. The lithium-ion secondary battery according to any one of claims 1 to 4,

the first cyclic compound is a compound represented by the following formula (7),

the second cyclic compound is a compound represented by the following formula (8),

the third cyclic compound is a compound represented by the following formula (9),

wherein X17 to X24 are each independently any group of an oxy group and an imino group, M27 to M36 are each independently a metal element, Y27 to Y36 are each independently a halogen element, and n27 to n36 are each independently an integer.

6. The lithium-ion secondary battery according to any one of claims 1 to 5,

the negative electrode further comprises at least one of a carbon material and a metal material,

the weight ratio of the cyclic compound to the cyclic compound, the carbon material, and the metallic material is 0.01 to 0.99.

7. A negative electrode for a lithium ion secondary battery, comprising a cyclic compound, and the cyclic compound comprises at least one of a first cyclic compound represented by formula (1), a second cyclic compound represented by formula (2), a third cyclic compound represented by formula (3), a fourth cyclic compound represented by formula (4), a fifth cyclic compound represented by formula (5), and a sixth cyclic compound represented by formula (6),

wherein X1 to X16 are each independently any one of oxy-O-and imino-NH-)R1 to R6 are each ethylene-CH₂-CH₂And any one of dicarbonyl-C (═ O) -, M1 to M26 are each a metal element, Y1 to Y26 are each a halogen element, and n1 to n26 are each an integer.

8. A cyclic compound comprising at least one of a first cyclic compound represented by formula (1), a second cyclic compound represented by formula (2), a third cyclic compound represented by formula (3), a fourth cyclic compound represented by formula (4), a fifth cyclic compound represented by formula (5), and a sixth cyclic compound represented by formula (6),

wherein X1 to X16 are each independently any one of oxy-O-and imino-NH-, and R1 to R6 are each independently ethylene-CH₂-CH₂And any one of dicarbonyl-C (═ O) -, M1 to M26 are each a metal element, Y1 to Y26 are each a halogen element, and n1 to n26 are each an integer.

Technical Field

The present technology relates to a cyclic compound having a cyclic structure, a negative electrode for a lithium ion secondary battery using the cyclic compound, and a lithium ion secondary battery including the negative electrode for a lithium ion secondary battery.

Background

As a result of the spread of various electronic devices, development of a lithium ion secondary battery that is small and lightweight and can achieve a high energy density is also underway as a power source.

A lithium ion secondary battery includes a positive electrode, a negative electrode containing a negative electrode active material and the like involved in charge and discharge reactions, and an electrolyte solution. Since the structure of the negative electrode has a large influence on the battery characteristics, various studies have been made on the structure of the negative electrode.

Specifically, in order to suppress a decrease in battery characteristics during high-temperature storage, the negative electrode contains a cyclic polyether, a cryptand (cryptand), and the like (see, for example, patent document 1). As the cyclic polyether, 4, 10-diaza-12-crown 4-ether or the like is used.

Disclosure of Invention

Electronic devices equipped with lithium ion secondary batteries are becoming increasingly higher in performance and more versatile. Therefore, the frequency of use of the electronic device increases, and the use environment of the electronic device also expands. However, there is still room for improvement in battery characteristics of lithium ion secondary batteries.

The present technology is directed to the invention of this problem, and an object thereof is to provide a cyclic compound, a negative electrode for a lithium ion secondary battery, and a lithium ion secondary battery, which can obtain excellent battery characteristics.

The cyclic compound according to one embodiment of the present technology includes at least one of a first cyclic compound represented by formula (1), a second cyclic compound represented by formula (2), a third cyclic compound represented by formula (3), a fourth cyclic compound represented by formula (4), a fifth cyclic compound represented by formula (5), and a sixth cyclic compound represented by formula (6).

[ solution 1]

(X1-X16 each represent any one of an oxy (-O-) group and an imino (-NH-) group, and R1-R6 each represent an ethylene (-CH-) group₂-CH₂-) and a dicarbonyl group (-C (═ O) -). M1 to M26 are each a metal element. Y1 to Y26 are each a halogen element. n1 to n26 are each an integer. )

The negative electrode for a lithium-ion secondary battery according to an embodiment of the present technology includes a cyclic compound having the same structure as the above-described cyclic compound according to an embodiment of the present technology.

The lithium ion secondary battery according to an embodiment of the present technology includes a positive electrode, a negative electrode, and an electrolyte solution, and the negative electrode has the same configuration as the negative electrode for a lithium ion secondary battery according to the above-described embodiment of the present technology.

According to the cyclic compound, the negative electrode for a lithium ion secondary battery, or the lithium ion secondary battery of the present technology, since the cyclic compound contains at least one of the first cyclic compound, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound, excellent battery characteristics can be obtained.

The effects of the present technology are not necessarily limited to the effects described here, and may be any of a series of effects associated with the present technology described later.

Drawings

Fig. 1 is a cross-sectional view showing the structure of a lithium-ion secondary battery (cylindrical type) according to an embodiment of the present technology.

Fig. 2 is an enlarged cross-sectional view of a main portion of the lithium-ion secondary battery shown in fig. 1.

Fig. 3 is a perspective view showing the structure of another lithium-ion secondary battery (laminate film type) according to an embodiment of the present technology.

Fig. 4 is an enlarged cross-sectional view of a main portion of the lithium-ion secondary battery shown in fig. 3.

Fig. 5 is a cross-sectional view showing the structure of a secondary battery (coin type) for testing.

Detailed Description

Hereinafter, an embodiment of the present technology will be described in detail with reference to the drawings. The description sequence is as follows.

1. Cyclic compound

1-1. constitution

1-2. method of manufacture

1-3. action and Effect

2. Lithium ion secondary battery and negative electrode for lithium ion secondary battery (cylindrical type)

2-1. formation

2-2. work

2-3. preparation method

2-4. Effect and Effect

3. Lithium ion secondary battery and negative electrode for lithium ion secondary battery (laminate film type)

3-1. formation

3-2. work

3-3. method of manufacture

3-4. action and Effect

4. Use of cyclic compounds

5. Lithium ion secondary battery and use of negative electrode for lithium ion secondary battery

<1. Cyclic Compound >

First, a cyclic compound (hereinafter simply referred to as "cyclic compound") according to an embodiment of the present technology will be described.

The cyclic compound described herein is a compound having a specific cyclic structure as described later. The use of the cyclic compound is not particularly limited, and the cyclic compound can be used in various applications. An example of the use of the cyclic compound will be described later.

<1-1. constitution >

The cyclic compound includes any one or two or more of a first cyclic compound represented by formula (1), a second cyclic compound represented by formula (2), a third cyclic compound represented by formula (3), a fourth cyclic compound represented by formula (4), a fifth cyclic compound represented by formula (5), and a sixth cyclic compound represented by formula (6). The first cyclic compound may be of only one kind or two or more kinds. One kind of such a compound may be used, or two or more kinds thereof may be used, and the same applies to each of the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound.

[ solution 2]

(X1-X16 each represent any one of an oxy (-O-) group and an imino (-NH-) group, and R1-R6 each represent an ethylene (-CH-) group₂-CH₂-) and a dicarbonyl group (-C (═ O) -). M1 to M26 are each a metal element. Y1 to Y26 are each a halogen element. n1 to n26 are each an integer. )

The cyclic compound has a cyclic structure including two or more dicarbonyl groups, and more specifically, has a cyclic skeleton represented by each of formulas (1) to (6). In addition, a covalent bond is represented by a solid line and a coordinate bond is represented by a dotted line in each of formulas (1) to (6). The same applies to the following.

In these cyclic skeletons, metal atoms (M1 to M26) are introduced by coordinate bonds and covalent bonds. Specifically, in the cyclic skeleton represented by each of the formulae (1) and (4), a metal atom (M1, M2, M11 to M14) is introduced to the outside of the cyclic skeleton by a coordinate bond. In addition, in the cyclic skeleton represented by each of formulae (2), (3), (5) and (6), a metal atom (M3, M4, M7, M8, M15 to M18, M21 to M24) is introduced outside the cyclic skeleton by a coordinate bond, and a metal atom (M5, M6, M9, M10, M19, M20, M25, M26) is introduced inside the cyclic skeleton by a coordinate bond and a covalent bond.

That is, the first cyclic compound, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound are each an organic-inorganic hybrid compound in which an inorganic portion (metal compound) is introduced into an organic portion (cyclic skeleton). Further, the detailed configuration of each of the first cyclic compound, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound will be described later.

The cyclic compound has advantages as described below.

First, a cyclic compound can smoothly intercalate and deintercalate a substance using the internal space (ligand field) of a cyclic skeleton. Accordingly, when a cyclic compound is used in an electrochemical device, the cyclic compound functions as an active material that intercalates and deintercalates electrode reaction substances, as with a carbon material or the like described later. The electrode reactant is a substance used for an electrode reaction, and is, for example, lithium in the case where the electrochemical device is a lithium ion secondary battery.

Secondly, the cyclic compound has excellent stretchability because it can expand and contract like a spring in response to an external force by utilizing the stretchability of the cyclic skeleton. Accordingly, for example, when a cyclic compound is used in an electrochemical device, the stress (expansion and contraction phenomenon) generated inside the electrochemical device is relaxed by the cyclic compound, and therefore the electrochemical device is less likely to expand and contract.

Third, in the cyclic compound, as described above, a metal atom (M1 to M26) is introduced into the cyclic skeleton by a coordinate bond and a covalent bond. Accordingly, for example, in the case where a cyclic compound is used for an electrochemical device, the cyclic compound makes it easier for an electrode reactant to be inserted into and extracted from the electrode by the electrochemical capacity of a metal atom, and the potential of an electrode including the cyclic compound is increased by the coordination potential of the metal atom (metal species), as compared with the case where no metal atom is introduced into the cyclic skeleton.

[ first Cyclic Compound ]

As shown in the formula (1), the first cyclic compound has a cyclic skeleton including two or more dicarbonyl groups, and a metal atom (M1, M2) is introduced outside the cyclic skeleton by a coordinate bond.

In the first cyclic compound, two oxygen atoms forming a dicarbonyl group are coordinately bonded to a metal (M1), and two oxygen atoms forming another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bonded to a metal atom (M2). Wherein the metal atom (M1) is covalently bonded to n1 halogen atoms (Y1), and the metal atom (M2) is covalently bonded to n2 halogen atoms (Y2).

(X1 to X8)

As described above, if X1 to X8 are each one of an oxy group and an imino group, there is no particular limitation. That is, all of X1 to X8 may be oxy groups, all of X1 to X8 may be imino groups, and a part of X1 to X8 may be oxy groups and the rest may be imino groups.

Among them, it is preferable that all of X1 to X8 are oxy groups, or all of X1 to X8 are imino groups. This is because the first cyclic compound becomes more easily stretchable.

(R1、R2)

As described above, when R1 and R2 are each one of an ethylene group and a dicarbonyl group, there is no particular limitation. That is, both R1 and R2 may be ethylene, both R1 and R2 may be dicarbonyl, and one of R1 and R2 may be ethylene and the other may be dicarbonyl. Accordingly, the first cyclic compound has two to four dicarbonyl groups.

(M1、M2)

As described above, when M1 and M2 are each a metal element, there is no particular limitation. More specifically, as described above, there is no particular limitation on the metal atoms (metal elements) in which M1 and M2 are each a metal atom capable of coordinately bonding to two oxygen atoms. The types of M1 and M2 may be the same or different, for example.

Specifically, the metal element is, for example, tin (Sn), titanium (Ti), silicon (Si), copper (Cu), manganese (Mn), iron (Fe), niobium (Nb), nickel (Ni), cobalt (Co), aluminum (Al), zirconium (Zr), or the like. This is because the metal atoms (M1, M2) are easily coordinated to the cyclic skeleton. Accordingly, the first cyclic compound is easily expanded and contracted, and the potential of the electrode including the first cyclic compound is sufficiently increased.

(Y1、Y2)

As described above, when Y1 and Y2 are each a halogen element, there is no particular limitation. The type of Y1 and the type of Y2 may be the same or different, for example. The number of n 1Y 1 may be, for example, only one, or two or more. One kind or two or more kinds of such kinds may be used, and the same applies to the kinds of n 2Y 2.

Specifically, Y1 and Y2 are, for example, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), or the like. This is because the metal atoms (M1, M2) become easily coordinated to the cyclic skeleton. Accordingly, the first cyclic compound becomes easily stretchable and contractible, and the potential of the electrode including the first cyclic compound is sufficiently increased.

(n1、n2)

n1 represents the number of Y1 bonded to M1, and the value of n1 is determined depending on the type of M1. n2 represents the number of Y2 bonded to M2, and the value of n2 is determined depending on the type of M2. The value of n1 and the value of n2 may be the same as or different from each other, for example.

The value of n1 is not particularly limited as long as it is an integer determined according to the type of M1, and is, for example, 2 or 4, as described above. The value of n2 is not particularly limited as long as it is an integer determined according to the type of M2, and is, for example, 2 or 4, as described above.

[ second Ring-shaped Compound ]

As shown in formula (2), the second cyclic compound is a compound having a cyclic oxygen skeleton including two or more dicarbonyl groups, and having a metal atom (M3 to M6) introduced into the cyclic oxygen skeleton by a coordinate bond. More specifically, the second cyclic compound is a compound in which a metal atom (M3, M4) is introduced outside the cyclic oxygen skeleton by a coordinate bond, and a metal atom (M5, M6) is introduced inside the cyclic oxygen skeleton by a coordinate bond.

In the second cyclic compound, two oxygen atoms forming a dicarbonyl group are coordinately bonded to the metal atom (M3), and two oxygen atoms forming another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bonded to the metal atom (M4). Wherein the metal atom (M3) is covalently bonded to n3 halogen atoms (Y3), and the metal atom (M4) is covalently bonded to n4 halogen atoms (Y4).

In addition, in the second cyclic compound, two oxygen atoms located on both sides of R3 are coordinately bound to the metal atom (M5), and two oxygen atoms located on both sides of R4 are coordinately bound to the metal atom (M6). Wherein the metal atom (M5) is covalently bonded to n5 halogen atoms (Y5), and the metal atom (M6) is covalently bonded to n6 halogen atoms (Y6).

(R3、R4)

The details of R3 and R4 are the same as those of R1 and R2, respectively. That is, the second cyclic compound has two to four dicarbonyl groups.

(M3-M6)

The details regarding each of M3 to M6 are the same as those regarding each of M1 and M2. That is, as described above, there is no particular limitation if each of M3 to M6 is a metal atom (metal element) capable of coordinately bonding to two oxygen atoms. The types of M3 to M6 may be the same or different, for example. Of course, only some of M3 to M6 may be the same type.

(Y3-Y6)

The details regarding Y3 through Y6 are the same as those regarding Y1 and Y2, respectively. The types of Y3 to Y6 may be the same or different, for example. Of course, only some of Y3 to Y6 may be the same type. The number of n 3Y 3 may be, for example, only one, or two or more. One kind or two or more kinds of such kinds may be used, and the same applies to the kinds of n 4Y 4, n 5Y 5, and n 6Y 6.

(n3 to n6)

The details regarding n3 through n6 are the same as those regarding n1 and n2, respectively. The value of n3 is determined according to the kind of M3, and the value of n4 is determined according to the kind of M4. The value of n5 is determined according to the kind of M5, and the value of n6 is determined according to the kind of M6. The value of each of n3 to n6 is not particularly limited as long as it is an integer determined from M3 to M6, and is, for example, 2 or 4.

[ third Cyclic Compound ]

As shown in formula (3), the third cyclic compound has a cyclic nitrogen skeleton including two or more dicarbonyl groups, and a metal atom (M7 to M10) is introduced into the cyclic nitrogen skeleton by a coordinate bond or a covalent bond. More specifically, the third cyclic compound is a compound in which a metal atom (M7, M8) is introduced outside the cyclic nitrogen skeleton by a coordinate bond, and a metal atom (M9, M10) is introduced inside the cyclic nitrogen skeleton by a coordinate bond and a covalent bond.

In the third cyclic compound, two oxygen atoms forming a dicarbonyl group are coordinately bonded to a metal atom (M7), and two oxygen atoms forming another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bonded to a metal atom (M8). Wherein the metal atom (M7) is covalently bonded to n7 halogen atoms (Y7), and the metal atom (M8) is covalently bonded to n8 halogen atoms (Y8).

In addition, in the third cyclic compound, two nitrogen atoms located on both sides of R5 are covalently bonded to the metal atom (M9), the other two nitrogen atoms are coordinately bonded to the metal atom (M9), and two nitrogen atoms located on both sides of R6 are covalently bonded to the metal atom (M10), and the other two nitrogen atoms are coordinately bonded to the metal atom (M10). Wherein the metal atom (M9) is covalently bonded to n9 halogen atoms (Y9), and the metal atom (M10) is covalently bonded to n10 halogen atoms (Y10).

(R5，R6)

The details of R5 and R6 are the same as those of R1 and R2, respectively. That is, the third cyclic compound has two to four dicarbonyl groups.

(M7-M10)

The details regarding each of M7 to M10 are the same as those regarding each of M1 and M2. That is, as described above, there is no particular limitation on the metal atoms (metal elements) in which M7 and M8 are each a metal atom capable of coordinately bonding to two oxygen atoms. As described above, when M9 and M10 are each a metal atom (metal element) capable of covalently bonding to two nitrogen atoms and coordinately bonding to the other two nitrogen atoms, there is no particular limitation. The types of M7 to M10 may be the same or different, for example. Of course, only some of M7 to M10 may be the same type.

(Y7-Y10)

The details regarding Y7 through Y10 are the same as those regarding Y1 and Y2, respectively. The types of Y7 to Y10 may be the same or different, for example. Of course, only some of Y7 to Y10 may be the same type. The number of n 7Y 7 may be, for example, only one, or two or more. One kind or two or more kinds of such kinds may be used, and the same applies to the kinds of n 8Y 8, n 9Y 9, and n 10Y 10.

(n7 to n10)

The details regarding n7 through n10 are the same as those regarding n1 and n2, respectively. The value of n7 is determined according to the kind of M7, and the value of n8 is determined according to the kind of M8. The value of n9 is determined according to the kind of M9, and the value of n10 is determined according to the kind of M10. The value of each of n7 to n10 is not particularly limited as long as it is an integer determined from M7 to M10, and is, for example, 2 or 4.

[ fourth Cyclic Compound ]

The fourth cyclic compound is a compound having a cyclic skeleton including four dicarbonyl groups and having a metal atom (M11 to M14) introduced into the cyclic skeleton by a coordinate bond, as shown in formula (4). More specifically, the fourth cyclic compound is a compound in which a metal atom (M11 to M14) is introduced to the outside of the cyclic skeleton by a coordinate bond.

In the fourth cyclic compound, two oxygen atoms forming a dicarbonyl group are coordinately bonded to a metal atom (M11), and two oxygen atoms forming another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bonded to a metal atom (M12). Wherein the metal atom (M11) is covalently bonded to n11 halogen atoms (Y11), and the metal atom (M12) is covalently bonded to n12 halogen atoms (Y12).

In the third cyclic compound, two oxygen atoms forming dicarbonyl groups different from the 4 dicarbonyl groups are coordinately bonded to the metal atom (M13), and two oxygen atoms forming other dicarbonyl groups disposed opposite to the dicarbonyl groups are coordinately bonded to the metal atom (M14). Wherein the metal atom (M13) is covalently bonded to n13 halogen atoms (Y13), and the metal atom (M14) is covalently bonded to n14 halogen atoms (Y14).

(X9 to X16)

The details about each of X9 to X16 are the same as those about each of X1 to X8. That is, it is preferable that all of X9 to X16 are oxy groups, or all of X9 to X16 are imino groups. This is because the fourth cyclic compound becomes more easily scalable.

(M11-M14)

The details regarding each of M11 to M14 are the same as those regarding each of M1 and M2. That is, as described above, there is no particular limitation if each of M11 to M14 is a metal atom (metal element) capable of coordinately bonding to two oxygen atoms. The types of M11 to M14 may be the same or different, for example. Of course, only some of M11 to M14 may be the same type.

(Y11-Y14)

The details regarding Y11 through Y14 are the same as those regarding Y1 and Y2, respectively. The types of Y11 to Y14 may be the same or different, for example. Of course, only some of Y11 to Y14 may be the same type. The number of n 11Y 11 may be, for example, only one, or two or more. One kind or two or more kinds of such kinds may be used, and the same applies to the kinds of n 12Y 12, n 13Y 13, and n 14Y 14.

(n11 to n14)

The details regarding n11 through n14 are the same as those regarding n1 and n2, respectively. The value of n11 is determined according to the kind of M11, and the value of n12 is determined according to the kind of M12. The value of n13 is determined according to the kind of M13, and the value of n14 is determined according to the kind of M14. The value of each of n11 to n14 is not particularly limited as long as it is an integer determined from M11 to M14, and is, for example, 2 or 4.

[ fifth Ring-shaped Compound ]

The fifth cyclic compound is a compound having a cyclic oxygen skeleton containing four dicarbonyl groups and having a metal atom (M15 to M20) introduced into the cyclic oxygen skeleton by a coordinate bond, as shown in formula (5). More specifically, the fifth cyclic compound is a compound in which a metal atom (M15 to M18) is introduced to the outside of the cyclic oxygen skeleton by a coordinate bond, and a metal atom (M19, M20) is introduced to the inside of the cyclic oxygen skeleton by a coordinate bond.

In the fifth cyclic compound, two oxygen atoms forming a dicarbonyl group are coordinately bonded to the metal atom (M15), and two oxygen atoms forming another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bonded to the metal atom (M16). Wherein the metal atom (M15) is covalently bonded to n15 halogen atoms (Y15), and the metal atom (M16) is covalently bonded to n16 halogen atoms (Y16).

In the fifth cyclic compound, two oxygen atoms forming dicarbonyl groups different from the four dicarbonyl groups are covalently bonded to the metal atom (M17), and two oxygen atoms forming other dicarbonyl groups disposed opposite to the dicarbonyl groups are coordinately bonded to the metal atom (M18). Wherein the metal atom (M17) is covalently bonded to n17 halogen atoms (Y17), and the metal atom (M18) is covalently bonded to n18 halogen atoms (Y18).

Further, in the fifth cyclic compound, two oxygen atoms located on both sides of the dicarbonyl group are coordinately bound to the metal atom (M19), and two oxygen atoms located on both sides of another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bound to the metal atom (M20). Wherein the metal atom (M19) is covalently bonded to n19 halogen atoms (Y19), and the metal atom (M20) is covalently bonded to n20 halogen atoms (Y20).

(M15-M20)

The details regarding each of M15 to M20 are the same as those regarding each of M1 and M2. That is, as described above, there is no particular limitation if each of M15 to M20 is a metal atom (metal element) capable of coordinately bonding to two oxygen atoms. The types of M15 to M20 may be the same or different, for example. Of course, only some of M15 to M20 may be the same type.

(Y15-Y20)

The details regarding Y15 through Y20 are the same as those regarding Y1 and Y2, respectively. The types of Y15 to Y20 may be the same or different, for example. Of course, only some of Y15 to Y20 may be the same type. The number of n 15Y 15 may be, for example, only one, or two or more. One kind or two or more kinds of such kinds may be used, and the same applies to the kinds of n 16Y 16, n 17Y 17, n 18Y 18, n 19Y 19, and n 20Y 20.

(n15 to n20)

The details regarding n15 through n20 are the same as those regarding n1 and n2, respectively. The value of n15 is determined according to the kind of M15, and the value of n16 is determined according to the kind of M16. The value of n17 is determined according to the kind of M17, and the value of n18 is determined according to the kind of M18. The value of n19 is determined according to the kind of M19, and the value of n20 is determined according to the kind of M20. The value of each of n15 to n20 is not particularly limited as long as it is an integer determined from M15 to M20, and is, for example, 2 or 4.

[ sixth Cyclic Compound ]

As shown in formula (6), the sixth cyclic compound is a compound having a cyclic nitrogen skeleton including four dicarbonyl groups, and having a metal atom (M21 to M26) introduced into the cyclic nitrogen skeleton by a coordinate bond and a covalent bond. More specifically, the sixth cyclic compound is a compound in which a metal atom (M21 to M24) is introduced to the outside of the cyclic nitrogen skeleton by a coordinate bond, and a metal atom ((M25, M26)) is introduced to the inside of the cyclic nitrogen skeleton by a coordinate bond and a covalent bond.

In the sixth cyclic compound, two oxygen atoms forming a dicarbonyl group are coordinately bonded to a metal atom (M21), and two oxygen atoms forming another dicarbonyl group disposed opposite to the dicarbonyl group are coordinately bonded to a metal atom (M22). Wherein the metal atom (M21) is covalently bonded to n21 halogen atoms (Y21), and the metal atom (M22) is covalently bonded to n22 halogen atoms (Y22).

In the sixth cyclic compound, two oxygen atoms forming dicarbonyl groups different from the four dicarbonyl groups are covalently bonded to the metal atom (M23), and two oxygen atoms forming other dicarbonyl groups disposed opposite to the dicarbonyl groups are coordinately bonded to the metal atom (M24). Wherein the metal atom (M23) is covalently bonded to n23 halogen atoms (Y23), and the metal atom (M24) is covalently bonded to n24 halogen atoms (Y24).

Further, in the sixth cyclic compound, two nitrogen atoms located on both sides of the dicarbonyl group are covalently bonded to the metal atom (M25), the other two nitrogen atoms are coordinately bonded to the metal atom (M25), two nitrogen atoms located on both sides of the other dicarbonyl group disposed opposite to the dicarbonyl group are covalently bonded to the metal atom (M26), and the other two nitrogen atoms are coordinately bonded to the metal atom (M26). Wherein the metal atom (M25) is covalently bonded to n25 halogen atoms (Y25), and the metal atom (M26) is covalently bonded to n26 halogen atoms (Y26).

(M21-M26)

The details regarding each of M21 to M26 are the same as those regarding each of M1 and M2. That is, as described above, there is no particular limitation if each of M21 to M24 is a metal atom (metal element) capable of coordinately bonding to two oxygen atoms. As described above, M25 and M26 are not particularly limited as long as each is a metal atom (metal element) capable of covalently bonding to two nitrogen atoms and coordinately bonding to the other two nitrogen atoms. The types of M21 to M26 may be the same or different, for example. Of course, only some of M21 to M26 may be the same type.

(Y21-Y26)

The details regarding Y21 through Y26 are the same as those regarding Y1 and Y2, respectively. The types of Y21 to Y26 may be the same or different, for example. Of course, only some of Y21 to Y26 may be the same type. The number of n 21Y 21 may be, for example, only one, or two or more. One kind or two or more kinds of such kinds may be used, and the same applies to the kinds of n 22Y 22, n 23Y 23, n 24Y 24, n 25Y 25, and n 26Y 26.

(n21 to n26)

The details regarding n21 through n26 are the same as those regarding n1 and n2, respectively. The value of n21 is determined according to the kind of M21, and the value of n22 is determined according to the kind of M22. The value of n23 is determined according to the kind of M23, and the value of n24 is determined according to the kind of M24. The value of n25 is determined according to the kind of M25, and the value of n26 is determined according to the kind of M26. The value of each of n21 to n26 is not particularly limited as long as it is an integer determined from M21 to M26, and is, for example, 2 or 4.

[ hydration ]

Further, the first cyclic compound may be subjected to, for example, hydration. Specifically, in order to hydrate the metal atoms (M1, M2) introduced outside the cyclic skeleton, each metal atom may be attached to one or more molecules of water (H) by electrostatic force, hydrogen bond, or the like₂O)。

The hydration can be performed in this manner, and the same applies to, for example, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound. Specifically, in the second cyclic compound, for example, each metal atom (M3, M4) introduced outside the cyclic oxygen skeleton may be hydrated. In the third cyclic compound, for example, each metal atom (M7, M8) introduced outside the cyclic nitrogen skeleton may be hydrated. In the fourth cyclic compound, for example, each metal atom (M11 to M14) introduced outside the cyclic skeleton may be hydrated. In the fifth cyclic compound, for example, each metal atom (M15 to M18) introduced outside the cyclic oxygen skeleton may be hydrated. In the sixth cyclic compound, for example, each metal atom (M21 to M24) introduced outside the cyclic nitrogen skeleton may be hydrated.

The number of water molecules attached to each metal atom (M1 to M4, M7, M8, M11 to M18, M21 to M24) is not particularly limited, and is, for example, two.

[ preferred Cyclic Compound ]

Among them, the first cyclic compound is preferably a compound represented by the following formula (7). The second cyclic compound is preferably a compound represented by the following formula (8). The third cyclic compound is preferably a compound represented by the following formula (9). This is because the first cyclic compound, the second cyclic compound, and the third cyclic compound each become more easily extensible and contractible.

[ solution 3]

(X17 to X24 each represent an oxygen group or an imino group; M27 to M36 each represent a metal element; Y27 to Y36 each represent a halogen element; n27 to n36 each represent an integer.)

The compound represented by the formula (7) is a compound in which R1 and R2 are each an ethylene group in the first cyclic compound represented by the formula (1). The details regarding each of X17 to X24, M27, M28, Y27, Y28, n27, and n28 are the same as those regarding each of X1 to X8, M1, M2, Y1, Y2, n1, and n2, for example.

The compound represented by the formula (8) is a compound in which R3 and R4 are ethylene groups in the second cyclic compound represented by the formula (2). The details regarding each of M29 to M32, Y29 to Y32, n29 to n32 are the same as those regarding each of M3 to M6, Y3 to Y6, n3 to n6, for example.

The compound represented by the formula (9) is a compound in which R5 and R6 are ethylene groups in the third cyclic compound represented by the formula (3). The details regarding each of M33 to M36, Y33 to Y36, n33 to n36 are the same as those regarding each of M7 to M10, Y7 to Y10, n7 to n10, for example.

[ specific examples of Cyclic Compound ]

Specific examples of the cyclic compound are shown below. However, a series of specific examples described below may be hydrated as described above.

(first Cyclic Compound)

The first cyclic compound is, for example, a compound represented by each of the following formulae (1-1) to (1-24), or the like. The compounds represented by each of the formulae (1-1) to (1-12) are compounds in which X1 to X8 shown in the formula (1) are all oxy groups, and the compounds represented by each of the formulae (1-13) to (1-24) are compounds in which X1 to X8 shown in the formula (1) are all imino groups.

Further, in each of the formulae (1-1) to (1-11) and the formulae (1-13) to (1-23), for example, a case where Y1 and Y2 shown in the formula (1) are each chlorine is shown. However, as described above, Y1 and Y2 are not limited to chlorine, and may be fluorine, bromine, or iodine. Specifically, for example, as shown in formulas (1 to 12) and (1 to 24), respectively, Y1 and Y2 may be fluorine, respectively.

[ solution 4]

[ solution 5]

[ solution 6]

(second Ring Compound)

The second cyclic compound is, for example, a compound represented by each of the following formulae (2-1) to (2-12), or the like.

Further, in each of the formulae (2-1) to (2-11), there are shown cases where, for example, Y3 to Y6 shown in the formula (2) are each chlorine. However, as described above, since each of Y3 to Y6 is not limited to chlorine, for example, Y3 to Y6 may be fluorine as shown in formulas (2 to 12).

In addition, in each of the formulas (2-1) to (2-12), for example, a case where M5 and M6 shown in the formula (2) are each tin is shown. However, as described above, each of M5 and M6 is not limited to tin, and may be any of titanium, silicon, copper, manganese, iron, niobium, nickel, cobalt, aluminum, and zirconium.

[ solution 7]

[ solution 8]

(third Cyclic Compound)

The third cyclic compound is, for example, a compound represented by each of the following formulae (3-1) to (3-12), and the like.

Further, in each of the formulae (3-1) to (3-11), for example, cases where Y7 to Y10 shown in the formula (3) are each chlorine are shown. However, as described above, since each of Y7 to Y10 is not limited to chlorine, for example, Y7 to Y10 may be fluorine, respectively, as shown in formulas (3 to 12).

In each of the formulae (3-1) to (3-12), for example, M9 and M10 shown in the formula (3) are each tin. However, as described above, each of M9 and M10 is not limited to tin, and may be any of titanium, silicon, copper, manganese, iron, niobium, nickel, cobalt, aluminum, and zirconium.

[ solution 9]

[ solution 10]

(fourth cyclic Compound)

The fourth cyclic compound is, for example, a compound represented by each of the following formulae (4-1) to (4-24), and the like. The compounds represented by each of the formulae (4-1) to (4-12) are compounds in which X9 to X16 represented by the formula (4) are all oxy groups, and the compounds represented by each of the formulae (4-13) to (4-24) are compounds in which X9 to X16 represented by the formula (4) are all imino groups.

Further, in each of the formulae (4-1) to (4-11) and the formulae (4-13) to (4-23), there are shown cases where, for example, Y11 to Y14 shown in the formula (4) are each chlorine. However, as mentioned above, since each of Y11 to Y14 is not limited to chlorine, for example, as shown in formulas (4-12) and (4-24), respectively, Y11 to Y14 may also be fluorine, respectively.

[ solution 11]

[ solution 12]

[ solution 13]

[ solution 14]

[ solution 15]

(fifth Ring Compound)

The fifth cyclic compound is, for example, a compound represented by each of the following formulae (5-1) to (5-12), and the like.

Further, in each of the formulae (5-1) to (5-11), there are shown cases where, for example, Y15 to Y20 shown in the formula (5) are each chlorine. However, as described above, since each of Y15 to Y20 is not limited to chlorine, for example, Y15 to Y20 may be fluorine as shown in formulas (5 to 12).

In addition, in each of the formulas (5-1) to (5-12), for example, a case where M19 and M20 shown in the formula (5) are each tin is shown. However, as described above, each of M19 and M20 is not limited to tin, and may be any of titanium, silicon, copper, manganese, iron, niobium, nickel, cobalt, aluminum, and zirconium.

[ solution 16]

[ solution 17]

[ solution 18]

(sixth Cyclic Compound)

The sixth cyclic compound is, for example, a compound represented by each of the following formulae (6-1) to (6-12).

Further, in each of the formulae (6-1) to (6-11), there are shown cases where, for example, Y21 to Y26 shown in the formula (6) are each chlorine. However, as described above, since each of Y21 to Y26 is not limited to chlorine, for example, Y21 to Y26 may be fluorine as shown in formulas (6 to 12).

In addition, in each of the formulas (6-1) to (6-12), for example, a case where M25 and M26 shown in formula (6) are each tin is shown. However, as described above, each of M25 and M26 is not limited to tin, and may be any of titanium, silicon, copper, manganese, iron, niobium, nickel, cobalt, aluminum, and zirconium.

[ solution 19]

[ solution 20]

[ solution 21]

<1-2. production method >

The first cyclic compound, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound are each produced, for example, by the following processes.

[ first Cyclic Compound ]

In the case of producing a compound in which all of X1 to X8 shown in the formula (1) are oxy groups in the first cyclic compound, by allowing HO-C₂H₄-O-C₂H₄-O-C₂H₄-OH is reacted with Cl-C (═ O) -Cl, thereby obtaining a first oxygen-containing compound represented by formula (10-1). In this case, a catalyst such as benzene, dioxane, pyridine, or the like may be used, and the reaction temperature may be adjusted as necessary. Thereafter, the first oxygen-containing compound is reacted with a metal compound (MY)₂Or MY₄) And (4) reacting. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. The metal compound used herein is a compound containing, for example, a metal element (M) corresponding to M1 and M2 shown in formula (1) and an element (Y) corresponding to Y1 and Y2 shown in formula (1) as constituent elements, and may be a hydrate. Thereby, the first cyclic compound was obtained.

In the case of producing a compound in which all of X1 to X8 shown in the formula (1) are imino groups in the first cyclic compound, by reacting H₂N-C₂H₄-NH-C₂H₄-NH-C₂H₄-NH₂And H₅C₂-O-C(＝O)-C(＝O)-O-C₂H₅Thereby obtaining a first nitrogen-containing compound represented by the formula (10-2). In this case, a catalyst such as sodium hydroxide or the like may be used, and the reaction temperature may be adjusted as necessary. Thereafter, the first nitrogen-containing compound is reacted with the above-mentioned metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. Thereby, the first cyclic compound was obtained.

[ solution 22]

[ second Ring-shaped Compound ]

In the case of producing the second cyclic compound, after the first oxygen-containing compound is reacted with the metal compound, the reactant is further reacted with the metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. Here, the former metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M5 and M6 shown in formula (2) and an element corresponding to each of Y5 and Y6 shown in formula (2), and may be a hydrate. On the other hand, the latter metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M3 and M4 shown in formula (2) and an element corresponding to each of Y3 and Y4 shown in formula (2), and may be a hydrate. Accordingly, a second cyclic compound was obtained.

[ third Cyclic Compound ]

In the case of producing the third cyclic compound, after the first nitrogen-containing compound is reacted with the metal compound, the reactant is further reacted with the metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. Here, the former metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M9 and M10 shown in formula (3) and an element corresponding to each of Y9 and Y10 shown in formula (3), and may be a hydrate. On the other hand, the latter metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M7 and M8 shown in formula (3) and an element corresponding to each of Y7 and Y8 shown in formula (3), and may be a hydrate. Accordingly, a third cyclic compound is obtained.

[ fourth Cyclic Compound ]

In the case of producing a fourth cyclic compound in which all of X9 to X16 shown in formula (4) are oxy groups, by reacting HO-C₂H₄-O-C₂H₄-O-C₂H₄-OH is reacted with Cl-C (═ O) -Cl, thereby obtaining a second oxygen-containing compound represented by formula (10-3). In this case, examples can be usedSuch as benzene, dioxane, pyridine, etc., and the reaction temperature may also be adjusted as necessary. Thereafter, the second oxygen-containing compound is reacted with the metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. The metal compound used herein is a compound containing, as constituent elements, for example, a metal element corresponding to each of M11 to M14 shown in formula (4) and an element corresponding to each of Y11 to Y14 shown in formula (4), and may also be a hydrate. Accordingly, a fourth cyclic compound was obtained.

In the case of producing a compound in which all of X9 to X16 shown in the formula (4) are imino groups as the fourth cyclic compound, by reacting H₂N-C₂H₄-NH-C₂H₄-NH-C₂H₄-NH₂And H₅C₂-O-C(＝O)-C(＝O)-O-C₂H₅Thereby obtaining a second nitrogen-containing compound represented by the formula (10-4). In this case, a catalyst such as sodium hydroxide or the like may be used, and the reaction temperature may be adjusted as necessary. Thereafter, the second nitrogen-containing compound is reacted with the above-mentioned metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. Accordingly, a fourth cyclic compound was obtained.

[ fifth Ring-shaped Compound ]

In the case of producing the fifth cyclic compound, after the second oxygen-containing compound is reacted with the metal compound, the reactant is further reacted with the metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. Here, the former metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M19 and M20 shown in formula (5) and an element corresponding to each of Y19 and Y20 shown in formula (5), and may be a hydrate. On the other hand, the latter metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M15 to M18 shown in formula (5) and an element corresponding to each of Y15 to Y18 shown in formula (5), and may also be a hydrate. Accordingly, a fifth cyclic compound was obtained.

[ sixth Cyclic Compound ]

In the case of producing the sixth cyclic compound, after the second nitrogen-containing compound is reacted with the metal compound, the reactant is further reacted with the metal compound. In this case, a catalyst such as methanol or the like may be used, and the reaction temperature may be adjusted as necessary. Here, the former metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M25 and M26 shown in formula (6) and an element corresponding to each of Y25 and Y26 shown in formula (6), and may be a hydrate. On the other hand, the latter metal compound is a compound containing, as constituent elements, for example, a metal element corresponding to each of M21 to M24 shown in formula (6) and an element corresponding to each of Y21 to Y24 shown in formula (6), and may be a hydrate. Accordingly, a sixth cyclic compound was obtained.

<1-3 > action and Effect

The cyclic compound includes any one of or two or more of a first cyclic compound, a second cyclic compound, a third cyclic compound, a fourth cyclic compound, a fifth cyclic compound, and a sixth cyclic compound. In this case, as described above, the cyclic compound can be smoothly inserted into the deintercalating electrode reactant and the like by the internal space (ligand field) of the cyclic skeleton and the metal atom (M1 to M26) introduced into the cyclic skeleton. Further, the cyclic compound has excellent stretchability due to the stretchability of the cyclic skeleton, and the potential of the electrode containing the cyclic compound is increased due to the metal atom introduced into the cyclic skeleton. This can improve the characteristics of an electrochemical device or the like including the cyclic compound.

In particular, when M1 to M26 represented by formulae (1) to (6) are each tin or the like, the metal atoms (M1 to M26) become easily coordinated to the cyclic skeleton. Accordingly, the cyclic compound is easily expanded and contracted, and the potential of the electrode including the cyclic compound is sufficiently increased, whereby a higher effect can be obtained.

In addition, when Y1 to Y26 shown in formulae (1) to (6) are each fluorine or the like, the metal atoms (M1 to M26) become easily coordinated to the cyclic skeleton. Accordingly, the cyclic compound is easily expanded and contracted, and the potential of the electrode including the cyclic compound is sufficiently increased, whereby a higher effect can be obtained.

In addition, if all of X1 to X8 shown in formula (1) are oxy groups or imino groups, and all of X9 to X16 shown in formula (4) are oxy groups or imino groups, each of the first cyclic compound and the fourth cyclic compound becomes more easily scalable, and thus higher effects can be obtained.

Further, when the first cyclic compound is a compound represented by formula (7), the second cyclic compound is a compound represented by formula (8), and the third cyclic compound is a compound represented by formula (9), the first cyclic compound, the second cyclic compound, and the third cyclic compound are more easily expanded and contracted, respectively, and thus higher effects can be obtained.

<2 > lithium ion secondary battery and negative electrode (cylindrical type) for lithium ion secondary battery

Next, an electrode for a lithium ion secondary battery (hereinafter simply referred to as "negative electrode") according to an embodiment of the present technology and a lithium ion secondary battery (hereinafter simply referred to as "lithium ion secondary battery") according to an embodiment of the present technology, which use the above cyclic compound, will be described.

The negative electrode is a part (one component) of a lithium ion secondary battery described below, and the negative electrode will be described below.

The lithium ion secondary battery described here is a secondary battery that obtains a battery capacity (capacity of the negative electrode 22 described later) by utilizing, for example, an intercalation/deintercalation phenomenon of lithium.

As for a plurality of candidates listed in a series of specific examples, materials, forming methods, and the like, which will be described below as appropriate, only one of them may be used, or two or more of them may be combined with each other.

<2-1. constitution >

Fig. 1 shows a sectional structure of the lithium-ion secondary battery, and fig. 2 enlarges the sectional structure of a main portion (wound electrode body 20) of the lithium-ion secondary battery shown in fig. 1. Here, only a part of the wound electrode body 20 is shown in fig. 2.

This lithium ion secondary battery is, for example, a cylindrical lithium ion secondary battery in which a battery element (wound electrode assembly 20) is housed inside a cylindrical battery can 11 as shown in fig. 1.

Specifically, the lithium ion secondary battery includes, for example, a pair of insulating plates 12 and 13 and a wound electrode assembly 20 inside a battery can 11. The wound electrode assembly 20 is, for example, a structure in which the cathode 21 and the anode 22 are laminated on each other with the separator 23 interposed therebetween, and then the cathode 21, the anode 22, and the separator 23 are wound. The wound electrode body 20 is impregnated with an electrolytic solution as a liquid electrolyte.

The battery can 11 has, for example, a hollow cylindrical structure with one end closed and the other end open, and contains a metal material such as iron. The surface of the battery can 11 may be plated with a metal material such as nickel. The insulating plates 12 and 13 are arranged so as to extend in a direction intersecting the wound peripheral surface of the wound electrode assembly 20, for example, and sandwich the wound electrode assembly 20 therebetween.

For example, the battery cover 14, the safety valve mechanism 15, and the thermistor element (PTC element) 16 are riveted to the open end of the battery can 11 via a seal 17, and the open end of the battery can 11 is sealed. The battery cover 14 is formed of the same material as that of the battery can 11, for example. The safety valve mechanism 15 and the thermistor element 16 are provided inside the battery cover 14, and the safety valve mechanism 15 is electrically connected to the battery cover 14 via the thermistor element 16. In the safety valve mechanism 15, for example, when the internal pressure of the battery can 11 becomes a constant value or more due to internal short circuit, external heating, or the like, the disk plate 15A is reversed to cut the electrical connection between the battery cover 14 and the wound electrode body 20. In order to prevent abnormal heat generation due to a large current, the resistance of the thermistor element 16 increases in response to a temperature increase. The sealing material 17 is made of, for example, an insulating material. The surface of the sealing member 17 may be coated with, for example, asphalt.

A center pin 24, for example, is inserted into a space 20C provided at the winding center of the wound electrode body 20. The center pin 24 may be omitted. A positive electrode lead 25 is connected to the positive electrode 21, and the positive electrode lead 25 is made of a conductive material such as aluminum. The positive electrode lead 25 is electrically connected to the battery lid 14 via, for example, the safety valve mechanism 15. A negative electrode lead 26 is connected to the negative electrode 22, and the negative electrode lead 26 contains a conductive material such as nickel. The negative electrode lead 26 is electrically connected to the battery can 11, for example.

[ Positive electrode ]

The positive electrode 21 includes, for example, a positive electrode current collector 21A and a positive electrode active material layer 21B provided on the positive electrode current collector 21A as shown in fig. 2. The positive electrode active material layer 21B may be provided on only one surface of the positive electrode current collector 21A, or may be provided on both surfaces of the positive electrode current collector 21A. In fig. 2, for example, a case where the positive electrode active material layer 21B is provided on both surfaces of the positive electrode current collector 21A is shown.

(Positive electrode collector)

The positive electrode current collector 21A contains a conductive material such as aluminum.

(Positive electrode active Material layer)

The positive electrode active material layer 21B contains a positive electrode material capable of inserting and extracting lithium as a positive electrode active material. The positive electrode active material layer 21B may further contain other materials such as a positive electrode binder and a positive electrode conductive agent.

(Positive electrode Material)

The positive electrode material contains, for example, a lithium compound, which is a generic term for a compound containing lithium as a constituent element. This is because a high energy density can be obtained. The type of the lithium compound is not particularly limited, and examples thereof include a lithium composite oxide and a lithium phosphate compound.

The lithium composite oxide is a generic term for oxides containing lithium and one or two or more other elements as constituent elements, and has a crystal structure of, for example, a layered rock salt type, a spinel type, or the like. The lithium phosphate compound is a generic term for a phosphate compound containing lithium and one or two or more other elements as constituent elements, and has a crystal structure such as an olivine type.

The other element is an element other than lithium. The kind of the other elements is not particularly limited, and among them, elements belonging to groups 2 to 15 in the long period periodic table are preferable. This is because a high voltage can be obtained. Specifically, the other elements are, for example, nickel, cobalt, manganese, iron, and the like.

The lithium composite oxide having a layered rock salt type crystal structure is, for example, LiNiO₂、LiCoO₂、LiCo_0.98Al_0.01Mg_0.01O₂、LiNi_0.5Co_0.2Mn_0.3O₂、LiNi_0.8Co_0.15Al_0.05O₂、LiNi_0.33Co_0.33Mn_0.33O₂、Li_1.2Mn_0.52Co_0.175Ni_0.1O₂And Li_1.15(Mn_0.65Ni_0.22Co_0.13)O₂And the like. The lithium composite oxide having a spinel-type crystal structure is, for example, LiMn₂O₄And the like. The lithium phosphate compound having an olivine-type crystal structure is, for example, LiFePO₄、LiMnPO₄、LiFe_0.5Mn_0.5PO₄And LiFe_0.3Mn_0.7PO₄And the like.

(Positive electrode Binder and Positive electrode conductive agent)

The positive electrode binder includes, for example, a synthetic rubber, a polymer compound, and the like. The synthetic rubber is, for example, styrene-butadiene rubber. The polymer compound is, for example, polyvinylidene fluoride, polyimide, or the like.

The positive electrode conductive agent contains a conductive material such as a carbon material. The carbon material is, for example, graphite, carbon black, acetylene black, ketjen black, or the like. The positive electrode conductive agent may be a metal material, a conductive polymer, or the like.

[ negative electrode ]

The anode 22 includes, for example, an anode current collector 22A and an anode active material layer 22B provided on the anode current collector 22A as shown in fig. 2. The anode active material layer 22B may be provided on only one surface of the anode current collector 22A, or may be provided on both surfaces of the anode current collector 22A, for example. Fig. 2 shows, for example, a case where the anode active material layer 22B is provided on both sides of the anode current collector 22A.

(negative electrode collector)

The negative electrode current collector 22A contains a conductive material such as copper. The surface of the negative electrode current collector 22A is preferably roughened by an electrolytic method or the like. This is because the adhesion of the anode active material layer 22B to the anode current collector 22A is improved by the anchor effect.

(negative electrode active material layer)

The anode active material layer 22B contains an anode material capable of inserting and extracting lithium as an anode active material. Here, the anode active material layer 22B may further contain other materials such as an anode binder and an anode conductive agent.

In order to prevent lithium metal from being accidentally deposited from the surface of the negative electrode 22 during charging, the capacity of the chargeable negative electrode material is preferably larger than the discharge capacity of the positive electrode 21. That is, the electrochemical equivalent of the anode material is preferably larger than that of the cathode 21.

(negative electrode Material)

The negative electrode material contains the above cyclic compound. That is, the negative electrode material contains any one of or two or more of the first cyclic compound, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound. The first cyclic compound, the second cyclic compound, the third cyclic compound, the fourth cyclic compound, the fifth cyclic compound, and the sixth cyclic compound may be each of only one kind or two or more kinds.

(other negative electrode Material)

In addition, other anode materials may be contained in the anode material, for example, together with the cyclic compound. The kind of the other material is not particularly limited, and examples thereof include carbon materials, metal materials, and the like.

The carbon material is a general term for a material containing carbon as a constituent element. This is because the crystal structure of the carbon material does not change substantially when lithium is intercalated and deintercalated, and therefore a high energy density can be stably obtained. In addition, this is because the carbon material also functions as an anode conductive agent, and therefore the conductivity of the anode active material layer 22B is improved.

Examples of the carbon material include easily graphitizable carbon, hardly graphitizable carbon, and graphite. Among them, the (002) plane spacing in the non-graphitizable carbon is preferably 0.37nm or more, and the (002) plane spacing in the graphite is preferably 0.34nm or less.

More specifically, examples of the carbon material include pyrolytic carbons, cokes, glassy carbon fibers, calcined organic polymer compounds, activated carbon, and carbon blacks. The coke includes, for example, pitch coke, needle coke, petroleum coke, or the like. The organic polymer compound calcined body is a calcined body obtained by calcining (carbonizing) a polymer compound such as a phenol resin or a furan resin at an appropriate temperature. The carbon material may be, for example, low-crystalline carbon heat-treated at a temperature of about 1000 ℃ or lower, or amorphous carbon. The shape of the carbon material is, for example, a fiber shape, a spherical shape, a granular shape, a scaly shape, or the like.

The metal-based material is a generic term including a material containing one or two or more of a metal element and a metalloid element as a constituent element. This is because a high energy density can be obtained.

The metal-based material may be a simple substance, an alloy, a compound, a mixture of two or more of these, or a material containing one or two or more phases of these. The alloy includes not only a compound composed of two or more metal elements but also a compound including one or two or more metal elements and one or two or more nonmetal elements. The alloy may contain one or two or more kinds of non-metallic elements. The structure of the metallic material is, for example, a solid solution, a eutectic crystal (eutectic mixture), an intermetallic compound, or a coexistent substance of two or more of these.

The metal element and the metalloid element are each an element capable of forming an alloy with lithium. Specifically, examples of the metal element and the metalloid element include magnesium, boron, aluminum, gallium, indium, silicon, germanium, tin, lead, bismuth, cadmium, silver, zinc, hafnium, zirconium, yttrium, palladium, platinum, and the like.

Among these, silicon and tin are preferable, and silicon is more preferable. This is because the ability to intercalate and deintercalate lithium is excellent, and therefore a high energy density can be remarkably obtained.

Specifically, the metal-based material may be a simple substance of silicon, a silicon alloy, a silicon compound, a tin simple substance, a tin alloy, a tin compound, a mixture of two or more of these, or a material containing one or more phases of these. Since the simple substance described here is merely a simple substance in the general sense, the simple substance may contain a trace amount of impurities. That is, the purity of the simple substance is not necessarily limited to 100%.

The alloy of silicon contains, for example, tin, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, chromium, and the like as constituent elements other than silicon. The silicon compound contains, for example, carbon, oxygen, and the like as a constituent element other than silicon. The compound of silicon may contain, for example, a series of constituent elements described for the alloy of silicon as constituent elements other than silicon.

Alloys of silicon and compounds of silicon, e.g. SiB₄、SiB₆、Mg₂Si、Ni₂Si、TiSi₂、MoSi₂、CoSi₂、NiSi₂、CaSi₂、CrSi₂、Cu₅Si、FeSi₂、MnSi₂、NbSi₂、TaSi₂、VSi₂、WSi₂、ZnSi₂、SiC、Si₃N₄、Si₂N₂O and SiO_v(v is more than 0 and less than or equal to 2), and the like. Where v may also range, for example, from 0.2 < v < 1.4.

The alloy of tin contains, for example, silicon, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, chromium, and the like as a constituent element other than tin. The tin compound contains carbon, oxygen, or the like as a constituent element other than tin. The tin compound may contain, for example, a series of constituent elements described for tin alloy as constituent elements other than tin.

Alloys of tin and compounds of tin are examplesSuch as SnO_w(0＜w≤2)、SnSiO₃And Mg₂Sn, and the like.

Among them, the negative electrode material preferably contains one or both of a carbon material and a metal material together with the cyclic compound. In this case, the negative electrode material may contain a carbon material together with the cyclic compound, may contain a metal material together with the cyclic compound, or may contain a carbon material and a metal material together with the cyclic compound. This is because a high theoretical capacity (battery capacity) can be obtained, and the anode active material layer 22B becomes sufficiently less likely to expand and contract at the time of charge and discharge.

The mixing ratio of the cyclic compound to the carbon material and the metal material is not particularly limited. Among them, the weight ratio of the cyclic compound to the cyclic compound, the carbon material, and the metal-based material (i.e., the weight of the cyclic compound/(the weight of the cyclic compound + the weight of the carbon material + the weight of the metal-based material)) is preferably 0.01 to 0.99, and more preferably 0.05 to 0.90. This is because the anode active material layer 22B sufficiently suppresses expansion and contraction at the time of charge and discharge and a high battery capacity can be obtained.

(negative electrode Binder and negative electrode conductive agent)

Details regarding the anode binder are the same as those regarding, for example, the cathode binder. The details regarding the negative electrode conductive agent are the same as those regarding the positive electrode conductive agent, for example.

(method of Forming negative electrode active Material layer)

The method of forming the anode active material layer 22B is not particularly limited, and examples thereof include a coating method, a vapor phase method, a liquid phase method, a flame spray method, and a firing method (sintering method). The coating method is, for example, a method of coating the negative electrode current collector 22A with a solution obtained by dissolving or dispersing a mixture of a negative electrode active material in a particulate (powder) form and a negative electrode binder or the like in an organic solvent or the like. The vapor phase method is, for example, a physical deposition method, a Chemical deposition method, and the like, and more specifically, a vacuum evaporation method, a sputtering method, an ion plating method, a laser ablation method, a thermal Chemical vapor deposition method, a Chemical vapor deposition method (CVD), a plasma Chemical vapor deposition method, and the like. The liquid phase method is, for example, a plating method or an electroless plating method. The flame spraying method is a method of spraying the negative electrode active material in a molten state or a semi-molten state onto the negative electrode current collector 22A. The firing method is, for example, a method in which the solution is applied to the negative electrode current collector 22A by a coating method, and then the solution (coating film) is heat-treated at a temperature higher than the melting point of the negative electrode binder or the like, and more specifically, an atmospheric firing method, a reaction firing method, a hot press firing method, or the like.

[ separator ]

The separator 23 is interposed between the positive electrode 21 and the negative electrode 22, for example, as shown in fig. 2, and allows lithium ions to pass therethrough while preventing short-circuiting due to contact between the electrodes. The separator 23 may be a porous film made of, for example, a synthetic resin, a ceramic, or the like, or a laminated film in which two or more kinds of porous films are laminated. The synthetic resin is, for example, polyethylene or the like.

In particular, the separator 23 may include, for example, the porous film (base material layer) and a polymer compound layer provided on the base material layer. The polymer compound layer may be provided on only one surface of the base material layer, or may be provided on both surfaces of the base material layer. This is because the separator 23 has improved adhesion to each of the cathode 21 and the anode 22, and therefore the wound electrode assembly 20 is less likely to be distorted. Accordingly, the decomposition reaction of the electrolytic solution is suppressed, and the leakage of the electrolytic solution impregnated in the base material layer is also suppressed. Accordingly, even if charge and discharge are repeated, the resistance of the lithium ion secondary battery becomes hard to increase, and the lithium ion secondary battery becomes hard to swell.

The polymer compound layer contains a polymer compound such as polyvinylidene fluoride. This is because the physical strength is excellent and the electrochemical stability is also excellent. The polymer compound layer may contain insulating particles such as inorganic particles. This is because of the improved safety. The kind of the inorganic particles is not particularly limited, and examples thereof include alumina and aluminum nitride.

[ electrolyte ]

As described above, the wound electrode body 20 is impregnated with the electrolyte solution. Therefore, the electrolyte solution is impregnated into, for example, the separator 23, and the cathode 21 and the anode 22, respectively.

The electrolyte solution contains a solvent and an electrolyte salt. The electrolyte may further contain various additives, for example.

(solvent)

The solvent includes, for example, a nonaqueous solvent (organic solvent), and the electrolyte containing the nonaqueous solvent is a so-called nonaqueous electrolyte. Examples of the nonaqueous solvent include cyclic carbonates, chain carboxylates, lactones, and nitrile (mononitrile) compounds. This is because excellent battery capacity, cycle characteristics, storage characteristics, and the like can be obtained.

The cyclic carbonate is, for example, ethylene carbonate, propylene carbonate, butylene carbonate, or the like. The chain carbonate is, for example, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, or the like. The chain carboxylic acid ester is, for example, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, methyl isobutyrate, methyl pivalate, ethyl pivalate, or the like. Lactones are, for example, γ -butyrolactone and γ -valerolactone. The nitrile compound is, for example, acetonitrile, methoxyacetonitrile, 3-methoxypropionitrile or the like.

Examples of the nonaqueous solvent include 1, 2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1, 3-dioxolane, 4-methyl-1, 3-dioxolane, 1, 3-dioxane, 1, 4-dioxane, N-dimethylformamide, N-methylpyrrolidone, N-methyl-2-oxazolidinone, N' -dimethyl-2-imidazolidinone, nitromethane, nitroethane, sulfolane, and dimethyl sulfoxide. Since the same advantages can be obtained.

The nonaqueous solvent may be an unsaturated cyclic carbonate, a halogenated carbonate, a sulfonate, an acid anhydride, a polynitrile compound, a diisocyanate compound, a phosphate, or the like. This is because the chemical stability of the electrolyte is improved.

Examples of the unsaturated cyclic carbonate include vinylene carbonate (1, 3-dioxol-2-one), vinyl ethylene carbonate (4-ethylene-1, 3-dioxolan-2-one), and methylene ethylene carbonate (4-methylene-1, 3-dioxolan-2-one). Halogenated carbonates are, for example, 4-fluoro-1, 3-dioxolan-2-one, 4, 5-difluoro-1, 3-dioxolan-2-one, fluoromethyl methyl carbonate, carbonBis (fluoromethyl) acid ester, difluoromethyl methyl carbonate, and the like. The sulfonate ester is, for example, 1, 3-propane sultone, 1, 3-propene sultone, or the like. The acid anhydride is, for example, succinic anhydride, ethanedisulfonic anhydride, sulfobenzoic anhydride, or the like. The polynitrile compound is, for example, succinonitrile or the like. Diisocyanate compounds such as OCN-C₆H₁₂-NCO and the like. The phosphate ester is, for example, trimethyl phosphate.

(electrolyte salt)

The electrolyte salt is, for example, a lithium salt. The electrolyte salt may further contain a salt other than a lithium salt, for example. The other salt is, for example, a salt of a light metal other than lithium.

The lithium salt is, for example, lithium hexafluorophosphate (LiPF)₆) Lithium tetrafluoroborate (LiBF)₄) Lithium bis (fluorosulfonylimide) (LiN (SO)₂F)₂) Lithium bistrifluoromethanesulfonylimide (LiN (CF)₃SO₂)₂) Lithium difluorophosphate (LiPF)₂O₂) And lithium monofluorophosphate (Li)₂PFO₃) And the like.

The content of the electrolyte salt is not particularly limited, and is, for example, 0.3mol/kg to 3.0mol/kg relative to the solvent.

<2-2. work >

The lithium ion secondary battery operates, for example, as follows. At the time of charging, lithium ions are extracted from the cathode 21, and the lithium ions are inserted into the anode 22 via the electrolytic solution. Lithium ions are extracted from the anode 22 at the time of discharge, and are inserted into the cathode 21 via the electrolytic solution.

<2-3. production method >

The lithium ion secondary battery is manufactured by, for example, the following process.

[ preparation of Positive electrode ]

First, a positive electrode active material is mixed with a positive electrode binder, a positive electrode conductive agent, and the like as necessary to prepare a positive electrode mixture. Subsequently, the positive electrode mixture is dispersed or dissolved in an organic solvent or the like, thereby obtaining a paste-like positive electrode mixture slurry. Finally, after the positive electrode mixture slurry is applied to both surfaces of the positive electrode current collector 21A, the positive electrode mixture slurry is dried to form the positive electrode active material layer 21B. After that, the positive electrode active material layer 21B may also be compression molded using a roll press or the like. In this case, the positive electrode active material layer 21B may be heated, or compression molding may be repeated a plurality of times.

[ preparation of negative electrode ]

The anode active material layer 22B is formed on both sides of the anode current collector 22A by the same procedure as the preparation procedure of the cathode 21 described above. Specifically, a negative electrode active material containing a cyclic compound is mixed with a negative electrode binder, a negative electrode conductive agent, and the like as needed to prepare a negative electrode mixture, and then the negative electrode mixture is dispersed in an organic solvent or the like to obtain a paste-like negative electrode mixture slurry. Subsequently, the negative electrode mixture slurry is applied to both surfaces of the negative electrode current collector 22A, and then the negative electrode mixture slurry is dried. Accordingly, the anode active material layer 22B is formed, thereby preparing the anode 22. After that, the anode active material layer 22B may also be compression molded.

[ preparation of electrolyte ]

The electrolyte salt is added to the vehicle and the vehicle is stirred. Accordingly, the electrolyte salt is dissolved, and an electrolytic solution is prepared.

[ Assembly of lithium ion Secondary Battery ]

First, the cathode lead 25 is connected to the cathode current collector 21A using a welding method or the like, and the anode lead 26 is connected to the anode current collector 22A using a welding method or the like. Subsequently, after the cathode 21 and the anode 22 are laminated on each other through the separator 23, the cathode 21, the anode 22, and the separator 23 are wound to form a wound body. Subsequently, the center pin 24 is inserted into the space 20C provided at the winding center of the winding body.

Subsequently, the wound body is accommodated in the battery can 11 together with the insulating plates 12 and 13 in a state where the wound body is sandwiched between the pair of insulating plates 12 and 13. In this case, the positive electrode lead 25 is connected to the safety valve mechanism 15 using a welding method or the like, and the negative electrode lead 26 is connected to the battery can 11 using a welding method or the like. Subsequently, the electrolyte solution is injected into the battery can 11, whereby the wound body is impregnated with the electrolyte solution. The cathode 21, the anode 22, and the separator 23 are thereby impregnated with the electrolytic solutions, respectively, to form the wound electrode assembly 20.

Finally, the battery cover 14, the safety valve mechanism 15, and the thermistor element 16 are mounted on the open end portion of the battery can 11 by caulking the open end portion of the battery can 11 via the seal 17. Thus, the wound electrode assembly 20 is enclosed inside the battery can 11, and the lithium-ion secondary battery is completed.

<2-4 > Effect and Effect

According to the cylindrical lithium ion secondary battery, the negative electrode 22 contains a cyclic compound. In this case, the anode 22 becomes easy to be inserted and extracted with lithium, expansion and contraction of the anode active material layer 22B at the time of charge and discharge are suppressed, and the potential of the anode 22 is increased. Thereby, excellent battery characteristics can be obtained.

In particular, when the anode 22 contains one or both of a carbon material and a metal material together with the cyclic compound and the weight ratio thereof is 0.01 to 0.99, the expansion and contraction of the anode active material layer 22B during charge and discharge are sufficiently suppressed and a high battery capacity can be obtained, thereby obtaining a higher effect.

In addition, since the negative electrode 22 used for the cylindrical lithium ion secondary battery contains the cyclic compound, the battery characteristics of the lithium ion secondary battery can be improved for the above reasons.

Other actions and effects of the cylindrical lithium ion secondary battery and the negative electrode 22 are the same as those of the cyclic compound.

<3. lithium ion secondary battery and negative electrode for lithium ion secondary battery (laminate film type) >

Next, other lithium ion secondary batteries and other negative electrodes will be described. In the following description, the components of the cylindrical lithium-ion secondary battery (see fig. 1 and 2) already described are referred to as needed.

Fig. 3 shows a three-dimensional configuration of another lithium ion secondary battery, and fig. 4 enlarges a sectional configuration of a main portion (wound electrode body 30) of the lithium ion secondary battery along the line IV-IV shown in fig. 3. Fig. 4 shows a state in which the wound electrode assembly 30 and the exterior member 40 are separated from each other.

<3-1. constitution >

This lithium ion secondary battery is, for example, a laminate film type lithium ion secondary battery in which a battery element (wound electrode assembly 30) is housed inside a film-shaped exterior member 40 having flexibility (or flexibility), as shown in fig. 4.

The wound electrode body 30 is, for example, a structure in which the positive electrode 33, the negative electrode 34, the separator 35, and the electrolyte layer 36 are wound after the positive electrode 33 and the negative electrode 34 are laminated with the separator 35 and the electrolyte layer 36 interposed therebetween. The surface of the wound electrode body 30 is protected by, for example, a protective tape 37. The electrolyte layer 36 is, for example, interposed between the positive electrode 33 and the separator 35, and between the negative electrode 34 and the separator 35.

The positive electrode lead 31 is connected to the positive electrode 33, and the positive electrode lead 31 is led out from the inside to the outside of the exterior member 40. The positive electrode lead 31 is formed of, for example, the same material as the positive electrode lead 25, and the positive electrode lead 31 has, for example, a sheet shape, a mesh shape, or the like.

The negative electrode lead 32 is connected to the negative electrode 34, and the negative electrode lead 32 is led out from the inside to the outside of the exterior member 40. The lead-out direction of the negative electrode lead 32 is the same as the lead-out direction of the positive electrode lead 31, for example. The material for forming the negative electrode lead 32 is, for example, the same as the material for forming the negative electrode lead 26, and the shape of the negative electrode lead 32 is, for example, the same as the shape of the positive electrode lead 31.

[ exterior component ]

The exterior member 40 is, for example, a single film that can be folded in the direction of arrow R shown in fig. 3. A recess 40U for accommodating the wound electrode assembly 30, for example, is provided in a part of the exterior member 40.

The exterior member 40 is, for example, a laminate (laminated film) in which a fusion-bonded layer, a metal layer, and a surface protection layer are laminated in this order from the inside to the outside. In the manufacturing process of the lithium ion secondary battery, for example, the outer sheathing members 40 are folded so that the welded layers face each other through the wound electrode assembly 30, and then the outer peripheral edges of the welded layers are welded to each other. The weld layer is a film containing a polymer compound such as polypropylene. The metal layer is a metal foil containing a metal material such as aluminum. The surface protection layer is a film containing a polymer compound such as nylon. The exterior member 40 includes, for example, two laminated films, and the two laminated films may be bonded to each other with an adhesive, for example.

An adhesive film 41 is inserted between the exterior member 40 and the positive electrode lead 31, for example, to prevent the entry of outside air. The adhesive film 41 is made of a material having adhesion to the positive electrode lead 31, and the material is, for example, a polyolefin resin such as polypropylene.

For example, an adhesive film 42 having the same function as the adhesive film 41 is inserted between the exterior member 40 and the negative electrode lead 32. The material for forming the adhesion film 42 is the same as the material for forming the adhesion film 41, except that it has adhesion to the negative electrode lead 32 instead of the positive electrode lead 31.

[ Positive electrode, negative electrode, and separator ]

The cathode 33 includes, for example, a cathode current collector 33A and a cathode active material layer 33B, and the anode 34 includes, for example, an anode current collector 34A and an anode active material layer 34B. The positive electrode current collector 33A, the positive electrode active material layer 33B, the negative electrode current collector 34A, and the negative electrode active material layer 34B have the same configurations as the positive electrode current collector 21A, the positive electrode active material layer 21B, the negative electrode current collector 22A, and the negative electrode active material layer 22B, for example. That is, the negative electrode 34 contains a cyclic compound, more specifically, contains one or two or more of a first cyclic compound, a second cyclic compound, a third cyclic compound, a fourth cyclic compound, a fifth cyclic compound, and a sixth cyclic compound. The configuration of the diaphragm 35 is the same as that of the diaphragm 23, for example.

[ electrolyte layer ]

The electrolyte layer 36 also contains a polymer compound together with an electrolytic solution. The electrolyte layer 36 described here is a so-called gel-like electrolyte, and the electrolyte solution is held by a polymer compound in the electrolyte layer 36. This is because high ionic conductivity (for example, 1mS/cm or more at room temperature) can be obtained and also leakage of the electrolytic solution is prevented. The electrolyte layer 36 may further contain other materials such as various additives.

(electrolyte and Polymer Compound)

The electrolyte solution has the same structure as that of the electrolyte solution used in the cylindrical secondary battery. The polymer compound may be a homopolymer, a copolymer, or both, for example. The homopolymer is, for example, polyvinylidene fluoride or the like, and the copolymer is, for example, a copolymer of vinylidene fluoride and hexafluoropropylene or the like.

In the electrolyte layer 36 as a gel-like electrolyte, the solvent contained in the electrolytic solution is a broad concept including not only a liquid material but also an ion-conductive material capable of dissociating an electrolyte salt. Accordingly, when a polymer compound having ion conductivity is used, the polymer compound is also included in the solvent.

[ use of electrolyte ]

In addition, an electrolytic solution may be used as it is instead of the electrolyte layer 36. In this case, the wound electrode body 30 (the cathode 33, the anode 34, and the separator 35) is impregnated with the electrolytic solution.

<3-2. working >

The lithium ion secondary battery operates, for example, as follows. At the time of charging, lithium ions are extracted from the cathode 33, and the lithium ions are inserted into the anode 34 via the electrolyte layer 36. At the time of discharge, lithium ions are extracted from the negative electrode 34, and the lithium ions are inserted into the positive electrode 33 via the electrolyte layer 36.

<3-3. production method >

The lithium ion secondary battery provided with the electrolyte layer 36 is manufactured by, for example, three processes described below.

[ first Process ]

First, the cathode 33 is prepared by the same procedure as that of the cathode 21, and the anode 34 is prepared by the same procedure as that of the anode 22. That is, in the case of preparing the positive electrode 33, the positive electrode active material layer 33B is formed on both surfaces of the positive electrode current collector 33A, and in the case of preparing the negative electrode 34, the negative electrode active material layer 34B is formed on both surfaces of the negative electrode current collector 34A.

Subsequently, the electrolytic solution was prepared by the same procedure as the preparation method of the electrolytic solution for the cylindrical secondary battery. Subsequently, after the electrolyte solution is mixed with the polymer compound, the organic solvent, and the like, the mixture is stirred to prepare a precursor solution. Subsequently, after the positive electrode 33 is coated with the precursor solution, the precursor solution is dried to form the electrolyte layer 36, and after the negative electrode 34 is coated with the precursor solution, the precursor solution is dried to form the electrolyte layer 36. Subsequently, the cathode lead 31 is connected to the cathode current collector 33A using a welding method or the like, and the anode lead 32 is connected to the anode current collector 34A using a welding method or the like. Subsequently, after the cathode 33 and the anode 34 are laminated on each other via the separator 35, the cathode 33, the anode 34, and the separator 35 are wound, thereby forming the wound electrode body 30. Subsequently, a protective tape 37 is attached to the surface of the wound electrode body 30.

Finally, after the exterior member 40 is folded so as to sandwich the wound electrode assembly 30, the outer peripheral edges of the exterior member 40 are bonded to each other by a heat welding method or the like. In this case, the adhesive film 41 is inserted between the positive electrode lead 31 and the exterior member 40, and the adhesive film 42 is inserted between the negative electrode lead 32 and the exterior member 40. Accordingly, the wound electrode assembly 30 is enclosed inside the exterior member 40, and the lithium-ion secondary battery is completed.

[ second Process ]

First, after the cathode 33 and the anode 34 are prepared, the cathode lead 31 is connected to the cathode 33, and the anode lead 32 is connected to the anode 34. Subsequently, after the cathode 33 and the anode 34 are laminated on each other via the separator 35, the cathode 33, the anode 34, and the separator 35 are wound to form a wound body. Subsequently, a protective tape 37 is attached to the surface of the wound body. Subsequently, after the exterior member 40 is folded so as to sandwich the roll body, the remaining outer peripheral edge portions of the exterior member 40 other than the outer peripheral edge portion of one side are bonded to each other by a heat welding method or the like, and the roll body is accommodated inside the bag-like exterior member 40.

Subsequently, the electrolytic solution, the monomer as a raw material of the polymer compound, and the polymerization initiator are mixed with other materials such as a polymerization inhibitor as necessary, and then the mixture is stirred to prepare the composition for an electrolyte. Subsequently, the electrolyte composition is injected into the bag-shaped exterior member 40, and then the exterior member 40 is sealed by a heat-sealing method or the like. Finally, the monomer is thermally polymerized to form a polymer compound. Accordingly, the electrolyte solution is held by the polymer compound, and the electrolyte layer 36 is formed. Accordingly, the wound electrode assembly 30 is enclosed inside the exterior member 40, and the lithium-ion secondary battery is completed.

[ third Process ]

First, a wound body was prepared in the same manner as in the second process described above, except that the separator 35 having a polymer compound layer formed on a base material layer was used, and then the wound body was housed inside the bag-like exterior member 40. Subsequently, after the electrolyte solution is injected into the exterior member 40, the opening of the exterior member 40 is sealed by a heat welding method or the like. Finally, the exterior member 40 is heated while applying a weight to the exterior member 40, whereby the separator 35 is brought into close contact with each of the positive electrode 33 and the negative electrode 34 via the polymer compound layer. Accordingly, the polymer compound layer impregnated with the electrolytic solution is gelled, and the electrolyte layer 36 is formed. Accordingly, the wound electrode assembly 30 is enclosed inside the exterior member 40, and the lithium-ion secondary battery is completed.

In this third process, the lithium-ion secondary battery becomes less likely to swell than in the first process. In the third step, the solvent and the monomer (raw material of the polymer compound) are less likely to remain in the electrolyte layer 36 than in the second step, and the positive electrode 33, the negative electrode 34, and the separator 35 are each sufficiently adhered to the electrolyte layer 36.

<3-4 > Effect and Effect

According to the multilayer film lithium ion secondary battery, since the negative electrode 34 contains the cyclic compound, excellent battery characteristics can be obtained for the same reason as described for the cylindrical lithium ion secondary battery. In addition, since the negative electrode 34 contains a cyclic compound, the battery characteristics of the lithium-ion secondary battery can be improved.

Other operations and effects of the multilayer film type lithium ion secondary battery are similar to those of the cylindrical type lithium ion secondary battery.

<4 > use of Cyclic Compound

The use of the cyclic compound is not particularly limited, and the cyclic compound can be applied to an electrochemical device and the like utilizing the intercalation and deintercalation phenomenon of an electrode reactant, as described above. The type of electrochemical device is not particularly limited, and examples thereof include a capacitor and the like, in addition to the lithium ion secondary battery. The cyclic compound is not limited to a lithium ion secondary battery using lithium as an electrode reactant, and may be applied to other secondary batteries using electrode reactants other than lithium. The cyclic compound can be applied to applications other than electrochemical devices.

<5. use of lithium ion secondary battery and negative electrode for lithium ion secondary battery >

The use of the lithium ion secondary battery is described below, for example. Since the use of the negative electrode is the same as that of the lithium ion secondary battery, the use of the negative electrode will be collectively described below. The negative electrode can be applied to secondary batteries other than lithium ion secondary batteries, electrochemical devices other than secondary batteries, and applications other than electrochemical devices.

The application of the lithium ion secondary battery is not particularly limited as long as it is a machine, equipment, appliance, device, system (an assembly of a plurality of pieces of equipment and the like) and the like that can be used as a driving power source, an electric power storage source for storing electric power, and the like. The lithium ion secondary battery used as a power source may be a main power source or an auxiliary power source. The main power source is a power source that is preferentially used regardless of the presence or absence of other power sources. The auxiliary power supply may be, for example, a power supply used in place of the main power supply, or may be a power supply that is switched with the main power supply as needed. When a lithium ion secondary battery is used as the auxiliary power supply, the type of the main power supply is not limited to the lithium ion secondary battery.

The applications of the lithium ion secondary battery are, for example, as follows. Electronic devices (including portable electronic devices) such as video cameras, digital still cameras, mobile phones, notebook personal computers, cordless phones, stereo headphones, portable radios, portable televisions, and portable information terminals. Portable living appliances such as electric shavers. A standby power supply, and a storage device such as a memory card. Electric tools such as drills and saws. A battery pack is mounted as a detachable power supply on a notebook personal computer or the like. Medical electronic devices such as cardiac pacemakers and hearing aids. Electric vehicles such as electric vehicles (including hybrid vehicles). And a power storage system such as a household battery system for storing electric power as needed. Of course, the lithium ion secondary battery may be used for other applications than the above-described applications.