阅读说明：本技术 固体电解质材料和使用它的电池 (Solid electrolyte material and battery using the same ) 是由 田中良明 酒井章裕 浅野哲也 宫崎晃畅 于 2019-10-31 设计创作，主要内容包括：本公开提供一种具有高的锂离子传导率的固体电解质材料。本公开的固体电解质材料包含Li、M、O和X。M是选自Nb和Ta中的至少一种元素。X是选自Cl、Br和I中的至少一种元素。(The present disclosure provides a solid electrolyte material having high lithium ion conductivity. The solid electrolyte material of the present disclosure contains Li, M, O, and X. M is at least one element selected from Nb and Ta. X is at least one element selected from Cl, Br and I.)

1. A solid electrolyte material comprising Li, M, O and X,

wherein the content of the first and second substances,

m is at least one element selected from Nb and Ta,

x is at least one element selected from Cl, Br and I.

2. The solid electrolyte material according to claim 1,

x is at least one element selected from Cl and Br.

3. The solid electrolyte material according to claim 1 or 2,

x comprises Cl.

4. The solid electrolyte material according to any one of claims 1 to 3,

which contains a 1 st crystalline phase comprising a first crystalline phase,

in an X-ray diffraction pattern of the 1 st crystal phase obtained by X-ray diffraction measurement using Cu-Kalpha rays, a peak is present in at least one of a 1 st range in which a value of a diffraction angle 2 theta is 12.9 DEG or more and 14.1 DEG or less and a 2 nd range in which a value of a diffraction angle 2 theta is 24.0 DEG or more and 25.8 DEG or less.

5. The solid electrolyte material according to claim 4,

there is a peak in both the 1 st range and the 2 nd range.

6. The solid electrolyte material according to claim 4 or 5,

it further contains a 2 nd crystal phase different from the 1 st crystal phase.

7. The solid electrolyte material according to any one of claims 1 to 6,

the molar ratio Li/M of Li to M is 1.0 or more and 2.0 or less.

8. The solid electrolyte material according to any one of claims 1 to 6,

the molar ratio of O to X, O/X, is 0.1 to 0.25.

9. The solid electrolyte material according to any one of claims 1 to 3,

which contains a 3 rd crystalline phase comprising,

in an X-ray diffraction pattern of the 3 rd crystal phase obtained by X-ray diffraction measurement using Cu — K α rays, a peak is present in a 3 rd range in which a value of a diffraction angle 2 θ is 12.3 ° or more and 15.3 ° or less.

10. The solid electrolyte material according to claim 9,

it further contains a 4 th crystalline phase different from the 3 rd crystalline phase.

11. The solid electrolyte material according to any one of claims 1 to 3, 9 and 10,

which is represented by the following composition formula (1),

Li_xMO_yX_(5+x-2y)···(1)

wherein x and y satisfy the following equation:

x is more than 0.1 and less than 7.0, and y is more than 0.4 and less than 1.9.

12. The solid electrolyte material according to claim 11,

x and y satisfy the following equation:

x is more than or equal to 0.2 and less than or equal to 6.0, and y is more than or equal to 0.5 and less than or equal to 1.8.

13. The solid electrolyte material according to claim 12,

x satisfies the formula: x is more than or equal to 0.5 and less than or equal to 2.0.

14. The solid electrolyte material according to claim 13,

x satisfies the formula: x is more than or equal to 0.9 and less than or equal to 1.1.

15. A battery comprising a positive electrode, a negative electrode, and an electrolyte layer disposed between the positive electrode and the negative electrode,

at least one selected from the group consisting of the positive electrode, the negative electrode and the electrolyte layer, comprising the solid electrolyte material according to any one of claims 1 to 14.

Technical Field

The present disclosure relates to a solid electrolyte material and a battery using the same.

Background

Patent document 1 discloses an all-solid battery using a sulfide solid electrolyte material.

Prior art documents

Patent document 1: japanese patent laid-open publication No. 2011-129312

Disclosure of Invention

Problems to be solved by the invention

An object of the present disclosure is to provide a solid electrolyte material having high lithium ion conductivity.

Means for solving the problems

The solid electrolyte material of the present disclosure contains Li, M, O, and X, wherein M is at least one element selected from Nb and Ta, and X is at least one element selected from Cl, Br, and I.

ADVANTAGEOUS EFFECTS OF INVENTION

The present disclosure provides a solid electrolyte material having high lithium ion conductivity.

Drawings

Fig. 1 shows a cross-sectional view of a battery 1000 according to embodiment 2.

Fig. 2 shows a cross-sectional view of an electrode material 1100 according to embodiment 2.

Fig. 3 shows a schematic view of a press molding die 300 used for evaluating the ion conductivity of a solid electrolyte material.

FIG. 4 is a graph showing the temperature dependence of the ionic conductivity of the solid electrolyte material of sample 1-1.

FIG. 5 is a graph showing X-ray diffraction patterns of the solid electrolyte materials of samples 1-1 and 1-8.

FIG. 6 is a graph showing an X-ray diffraction pattern of the solid electrolyte material of samples 1-1 to 1-4.

FIG. 7 is a graph showing an X-ray diffraction pattern of the solid electrolyte material of samples 1-5 to 1-7.

Fig. 8 is a graph showing the initial discharge characteristics of the battery of sample 1-1.

FIG. 9 is a graph showing the temperature dependence of the ionic conductivity of the solid electrolyte material of sample 2-1.

FIG. 10 is a graph showing an X-ray diffraction pattern of a solid electrolyte material of samples 2-1 to 2-13.

FIG. 11 is a graph showing an X-ray diffraction pattern of a solid electrolyte material of samples 2-14 to 2-22.

FIG. 12 is a graph showing an X-ray diffraction pattern of a solid electrolyte material of samples 2-23 to 2-28.

FIG. 13 is a graph showing the initial discharge characteristics of the battery of sample 2-1.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

(embodiment 1)

The solid electrolyte material of embodiment 1 contains Li, M, O, and X. M is at least one element selected from Nb and Ta. X is at least one element selected from Cl, Br and I. The solid electrolyte material of embodiment 1 has high lithium ion conductivity.

The solid electrolyte material according to embodiment 1 can be used to obtain a battery having excellent charge and discharge characteristics. An example of such a battery is an all-solid-state secondary battery.

The solid electrolyte material according to embodiment 1 can maintain high lithium ion conductivity in a range of a temperature range (for example, a range of-30 ℃ to 80 ℃) where a battery is expected to be used. Therefore, the battery using the solid electrolyte material of embodiment 1 can stably operate even in an environment where there is a temperature change.

From the viewpoint of safety, it is desirable that the solid electrolyte material of embodiment 1 does not contain sulfur. The sulfur-free solid electrolyte material does not generate hydrogen sulfide even when exposed to the atmosphere, and therefore is excellent in safety. Note that the sulfide solid electrolyte material disclosed in patent document 1 generates hydrogen sulfide if exposed to the atmosphere.

In order to improve the ion conductivity of the solid electrolyte material, the solid electrolyte material of embodiment 1 may be substantially composed of Li, M, O, and X. "the solid electrolyte material of embodiment 1 is substantially composed of Li, M, O, and X" means that the molar ratio of the total amount of substances of Li, M, O, and X to the total amount of substances of all elements constituting the solid electrolyte material of embodiment 1 is 90% or more. For example, the molar ratio may be 95% or more.

In order to improve the ion conductivity of the solid electrolyte material, the solid electrolyte material of embodiment 1 may be composed of only Li, M, O, and X.

In order to improve the ion conductivity of the solid electrolyte material, X may contain iodine (i.e., I). The molar ratio of I to X may be 30% or less.

In order to improve the ion conductivity of the solid electrolyte material, in the solid electrolyte material of embodiment 1, X may be at least one element selected from Cl and Br.

In order to improve the ion conductivity of the solid electrolyte material, X may contain Cl.

Hereinafter, the following will describe example 1 and example 2 of the solid electrolyte material of embodiment 1. Example 1 of the solid electrolyte material of embodiment 1 is described as "1 st solid electrolyte material". Example 2 of the solid electrolyte material of embodiment 1 is described as "solid electrolyte material 2".

< No. 1 solid electrolyte Material >

The 1 st solid electrolyte material contains a 1 st crystal phase, and has a peak in at least one of a 1 st range in which a value of a diffraction angle 2 theta is 12.9 DEG or more and 14.1 DEG or less and a 2 nd range in which a value of a diffraction angle 2 theta is 24.0 DEG or more and 25.8 DEG or less in an X-ray diffraction pattern of the 1 st crystal phase obtained by X-ray diffraction measurement using Cu-Kalpha rays. The 1 st crystal phase has high lithium ion conductivity. The 1 st solid electrolyte material contains the 1 st crystalline phase, and thus easily forms a path for lithium ion diffusion. As a result, the 1 st solid electrolyte material has high lithium ion conductivity.

The X-ray diffraction pattern can be obtained by X-ray diffraction measurement using Cu — K α rays (wavelengths of 1.5405 and 1.5444, i.e., wavelengths of 0.15405nm and 0.15444nm) by the θ -2 θ method.

The 1 st solid electrolyte material can be used to obtain a battery having excellent charge and discharge characteristics.

The diffraction angle of a diffraction peak in an X-ray diffraction pattern is defined as an angle representing the maximum intensity of a mountain-shaped portion having an SN ratio (i.e., the ratio of signal S to background noise N) of 3 or more and a half-value width of 10 ° or less. The half-value width is defined as the maximum intensity of the diffraction peak is I_MAXWhen the intensity is I_MAXThe width represented by the difference between the two diffraction angles for a value of half.

In the X-ray diffraction pattern of the 1 st solid electrolyte material, a peak may be present in both the 1 st range and the 2 nd range. Such a 1 st crystal phase has higher lithium ion conductivity. Therefore, the 1 st solid electrolyte material containing the 1 st crystal phase has higher lithium ion conductivity.

In order to further improve the ion conductivity of the solid electrolyte material, the 1 st solid electrolyte material may further contain a 2 nd crystal phase different from the 1 st crystal phase. That is, the 1 st solid electrolyte material may further contain a 2 nd crystal phase having a peak at a diffraction angle 2 θ different from that of the 1 st crystal phase. By containing the 2 nd crystal phase in the 1 st solid electrolyte material, conduction of lithium ions between the 1 st crystal phases can be promoted. As a result, the 1 st solid electrolyte material has higher lithium ion conductivity.

The 2 nd crystal phase may be interposed between the 1 st crystal phase.

In order to improve the ionic conductivity of the solid electrolyte material, the molar ratio Li/M of Li to M may be 1.0 or more and 2.0 or less. By selecting the value of the molar ratio Li/M in this way, the Li concentration is optimized.

In order to improve the ion conductivity of the solid electrolyte material, the molar ratio O/X of O to X may be 0.1 or more and 0.25 or less. By selecting the value of the molar ratio O/X in this way, the 1 st crystal phase can be easily realized.

< 2 nd solid electrolyte Material >

The 2 nd solid electrolyte material contains a 3 rd crystal phase, and has a peak in a 3 rd range having a diffraction angle 2 theta value of 12.3 DEG or more and 15.3 DEG or less in an X-ray diffraction pattern of the 3 rd crystal phase obtained by X-ray diffraction measurement using Cu-Kalpha rays. The 3 rd crystal phase has high ion conductivity. The 2 nd solid electrolyte material contains the 3 rd crystal phase, and thus a path for lithium ion diffusion is easily formed. As a result, the 2 nd solid electrolyte material has high lithium ion conductivity.

The X-ray diffraction pattern of the 2 nd solid electrolyte material was measured in the same manner as the X-ray diffraction pattern of the 1 st solid electrolyte material.

The 2 nd solid electrolyte material is used to obtain a battery having excellent charge and discharge characteristics.

The diffraction angle of the peak in the X-ray diffraction pattern of the 2 nd solid electrolyte material is defined in the same manner as that of the 1 st solid electrolyte material.

In order to further improve the ion conductivity of the solid electrolyte material, the 2 nd solid electrolyte material may further contain a 4 th crystal phase different from the 3 rd crystal phase. That is, the 2 nd solid electrolyte material may further contain a 4 th crystal phase having a peak at a diffraction angle 2 θ different from that of the 3 rd crystal phase. By containing the 4 th crystal phase in the 2 nd solid electrolyte material, conduction of lithium ions between the 3 rd crystal phases can be promoted. As a result, the 2 nd solid electrolyte material has higher lithium ion conductivity.

The 4 th crystalline phase may be interposed between the 3 rd crystalline phases.

The 2 nd solid electrolyte material may be a material represented by the following composition formula (1).

Li_xMO_yX_(5+x-2y)···(1)

Wherein formula (1) satisfies the following formula:

x is more than 0.1 and less than 7.0, and y is more than 0.4 and less than 1.9.

The solid electrolyte material represented by the composition formula (1) has high lithium ion conductivity.

In order to further improve the ion conductivity of the solid electrolyte material, formula (1) may satisfy the following formula:

x is more than or equal to 0.2 and less than or equal to 6.0, and y is more than or equal to 0.5 and less than or equal to 1.8.

In order to further improve the ion conductivity of the solid electrolyte material, formula (1) may satisfy the formula: x is more than or equal to 0.5 and less than or equal to 2.0. Preferably satisfies the formula: x is more than or equal to 0.9 and less than or equal to 1.1.

The element X may be partially missing. Specifically, the composition ratio of the element X may be smaller than a value estimated from the molar ratio of the raw materials of the solid electrolyte material (i.e., (5+ X-2y) in the composition formula (1)). For example, the amount of deficiency of the element X is within 30% of 5+ X-2 y.

O (i.e., oxygen) may be partially deficient.

In the case where the element X or O is absent, the interaction between the lithium ion and the anion becomes small, and therefore the lithium ion conductivity is further improved.

The shape of the solid electrolyte material of embodiment 1 is not limited. Examples of such shapes are needle-like, spherical and oval-spherical. The solid electrolyte material of embodiment 1 may be particles. The solid electrolyte material of embodiment 1 may be formed to have a particle or plate shape.

When the solid electrolyte material of embodiment 1 is in the form of particles (for example, spheres), the median particle diameter of the solid electrolyte material may be 0.1 μm or more and 100 μm or less, or 0.5 μm or more and 10 μm or less. Thus, the solid electrolyte material of embodiment 1 has higher ion conductivity. In addition, the solid electrolyte material of embodiment 1 and other materials can be well dispersed.

The median diameter of the particles means a particle diameter corresponding to 50% by volume in a volume-based particle size distribution (d 50). The volume-based particle size distribution can be measured by a laser diffraction measuring apparatus or an image analyzing apparatus.

In the case where the solid electrolyte material of embodiment 1 is in the form of particles (for example, spheres), the median particle diameter of the solid electrolyte material may be smaller than that of the active material. Thus, the solid electrolyte material and the active material of embodiment 1 can be formed in a good dispersion state.

< method for producing solid electrolyte Material >

The solid electrolyte material of embodiment 1 can be produced by the following method.

Raw meal is prepared with the target composition. Examples of the raw material powder are an oxide, a hydroxide, a halide or an acid halide (acid halide).

For example, in a solid electrolyte material composed of Li, Nb, O and Cl, when the molar ratio Li/M and the molar ratio O/X at the time of raw material mixing are 2.0 and 0.2, respectively, Li is prepared at a molar ratio of 1:1₂O and NbCl₅. The element species of M and X are determined by selecting the species of the raw powder. The molar ratios of Li/M and O/X are determined by selecting the mixing ratio of the raw material powders.

As another example, the target composition is LiNbOCl₄(in the composition formula (1), the values of x and y are equal to 1.0 and 1.0, respectively), LiCl and NbOCl were prepared in a molar ratio of 1:1₃. The element species of M and X are determined by selecting the species of the raw powder. The values of x and y in the composition formula (1) are determined by selecting the mixing ratio of the raw material powders.

The reaction product is obtained by subjecting a mixture of raw material powders to a mechanochemical reaction with each other in a mixing device such as a planetary ball mill (i.e., by a mechanochemical grinding method). The reactants may be fired in vacuum or in an inert atmosphere (e.g., an argon atmosphere or a nitrogen atmosphere). Alternatively, the mixture may be fired in vacuum or in an inert gas atmosphere to obtain a reactant. By these methods, the solid electrolyte material of embodiment 1 is obtained.

The solid electrolyte material of embodiment 1 can be made to have a target position of an X-ray diffraction peak (i.e., a crystal structure) by selecting the raw material powder, the mixing ratio of the raw material powders, and the reaction conditions.

The composition of the solid electrolyte material can be determined by, for example, ICP emission spectrometry, ion chromatography, inert gas melting-infrared absorption method, or EPMA (Electron Probe Micro Analyzer; Electron Probe microscopy). However, since the accuracy of measuring the oxygen amount is low, an error of about 10% may be included.

(embodiment 2)

Hereinafter, embodiment 2 will be described. The matters described in embodiment 1 are appropriately omitted.

The battery of embodiment 2 includes a positive electrode, an electrolyte layer, and a negative electrode. The electrolyte layer is disposed between the positive electrode and the negative electrode. At least one selected from the group consisting of a positive electrode, a negative electrode and an electrolyte layer contains the solid electrolyte material of embodiment 1. The battery of embodiment 2 has excellent charge and discharge characteristics.

Fig. 1 shows a cross-sectional view of a battery 1000 according to embodiment 2.

The battery 1000 includes a positive electrode 201, an electrolyte layer 202, and a negative electrode 203. The electrolyte layer 202 is disposed between the positive electrode 201 and the negative electrode 203.

The positive electrode 201 includes positive electrode active material particles 204 and solid electrolyte particles 100.

The electrolyte layer 202 contains an electrolyte material (e.g., a solid electrolyte material).

The negative electrode 203 contains negative electrode active material particles 205 and solid electrolyte particles 100.

The solid electrolyte particles 100 are particles containing the solid electrolyte material of embodiment 1. The solid electrolyte particles 100 may be particles containing the solid electrolyte material of embodiment 1 as a main component. The particles containing the solid electrolyte material of embodiment 1 as a main component refer to particles containing the solid electrolyte material of embodiment 1 as the largest component. The solid electrolyte particles 100 may be particles made of the solid electrolyte material according to embodiment 1.

The positive electrode 201 contains a material capable of occluding and releasing metal ions (e.g., lithium ions). The positive electrode 201 contains, for example, a positive electrode active material (for example, positive electrode active material particles 204).

Examples of the positive electrode active material are lithium-containing transition metal oxides, transition metal fluorides, polyanionic materials, fluorinated polyanionic materials, transition metal sulfides, transition metal oxysulfides, or transition metal oxynitrides. Examples of lithium-containing transition metal oxides are Li (NiCoAl) O₂、Li(NiCoMn)O₂Or LiCoO₂。

From the viewpoint of cost and safety of the battery, lithium phosphate may be used as the positive electrode active material.

When the positive electrode 201 contains the solid electrolyte material of embodiment 1 and X contains I (i.e., iodine), lithium iron phosphate can be used as the positive electrode active material. The solid electrolyte material of embodiment 1 containing I is easily oxidized. If lithium iron phosphate is used as the positive electrode active material, the oxidation reaction of the solid electrolyte material is suppressed. That is, formation of an oxide layer having low lithium ion conductivity can be suppressed. As a result, the battery has high charge and discharge efficiency.

The positive electrode 201 may contain not only the solid electrolyte material of embodiment 1 but also a transition metal oxyfluoride as a positive electrode active material. The solid electrolyte material according to embodiment 1 is difficult to form a resistive layer even if fluorinated with a transition metal oxyfluoride. As a result, the battery has high charge and discharge efficiency.

The transition metal oxyfluoride contains oxygen and fluorine. As an example, the transition metal oxyfluoride may be represented by the composition formula Li_pMe_qO_mF_nThe compound shown in the specification. Wherein Me is at least one element selected from the group consisting of Mn, Co, Ni, Fe, Al, Cu, V, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, W, B, Si and P, and satisfies the following formula: p is more than or equal to 0.5 and less than or equal to 1.5, q is more than or equal to 0.5 and less than or equal to 1.0, m is more than or equal to 1 and less than 2, and q is more than or equal to 0n is less than or equal to 1. An example of such a transition metal oxyfluoride is Li_1.05(Ni_0.35Co_0.35Mn_0.3)_0.95O_1.9F_0.1。

The median diameter of the positive electrode active material particles 204 may be 0.1 μm or more and 100 μm or less. When the median diameter of the positive electrode active material particles 204 is 0.1 μm or more, the positive electrode active material particles 204 and the solid electrolyte particles 100 can be formed in a good dispersion state in the positive electrode 201. This improves the charge/discharge characteristics of the battery. When the median diameter of the positive electrode active material particles 204 is 100 μm or less, the lithium diffusion rate in the positive electrode active material particles 204 increases. Therefore, the battery can operate with high output.

The median particle diameter of the positive electrode active material particles 204 may be larger than the solid electrolyte particles 100. This enables the positive electrode active material particles 204 and the solid electrolyte particles 100 to be in a good dispersion state.

In the positive electrode 201, the ratio of the volume of the positive electrode active material particles 204 to the total of the volume of the positive electrode active material particles 204 and the volume of the solid electrolyte particles 100 may be 0.30 or more and 0.95 or less from the viewpoint of the energy density and the output of the battery.

Fig. 2 shows a cross-sectional view of an electrode material 1100 according to embodiment 2. The electrode material 1100 is contained in the positive electrode 201, for example. In order to prevent the electrode active material particles 206 from reacting with the solid electrolyte particles 100, a coating layer 216 may be formed on the surface of the electrode active material particles 206. This can suppress an increase in the reaction overvoltage of the battery. Examples of the coating material contained in the coating layer 216 include a sulfide solid electrolyte, an oxide solid electrolyte, or a halide solid electrolyte.

In the case where the solid electrolyte particles 100 are sulfide solid electrolytes, the coating material may be the solid electrolyte material of embodiment 1, and X is at least one element selected from Cl and Br. Such a solid electrolyte material of embodiment 1 is less likely to be oxidized than a sulfide solid electrolyte. As a result, the reaction overvoltage of the battery can be suppressed from rising.

In the case where the solid electrolyte particle 100 is the solid electrolyte material of embodiment 1, and X contains I, the coating material may be the solid electrolyte material of embodiment 1, and X is at least one element selected from Cl and Br. The solid electrolyte material of embodiment 1 not containing I is less likely to be oxidized than the solid electrolyte material of embodiment 1 containing I. Therefore, the battery has high charge-discharge efficiency.

In the case where the solid electrolyte particles 100 are the solid electrolyte material of embodiment 1, and X contains I, the coating material may contain an oxide solid electrolyte. The oxide solid electrolyte may be lithium niobate having excellent stability even at a high potential. Thus, the battery has high charge and discharge efficiency.

The positive electrode 201 may be composed of a 1 st positive electrode layer containing a 1 st positive electrode active material and a 2 nd positive electrode layer containing a 2 nd positive electrode active material. Here, the 2 nd positive electrode layer is disposed between the 1 st positive electrode layer and the electrolyte layer 202, the 1 st positive electrode layer and the 2 nd positive electrode layer contain the solid electrolyte material of embodiment 1 including I, and the coating layer 216 is formed on the surface of the 2 nd positive electrode active material. With the above technical configuration, the solid electrolyte material of embodiment 1 contained in the electrolyte layer 202 can be inhibited from being oxidized by the 2 nd positive electrode active material. As a result, the battery has a high charge capacity. Examples of the coating material contained in the coating layer 206 include a sulfide solid electrolyte, an oxide solid electrolyte, a polymer solid electrolyte, and a halide solid electrolyte. However, when the coating material is a halide solid electrolyte, I is not contained as a halogen element. The 1 st positive electrode active material may be the same material as the 2 nd positive electrode active material, or may be a material different from the 2 nd positive electrode active material.

The thickness of the positive electrode 201 may be 10 μm or more and 500 μm or less from the viewpoint of energy density and output of the battery.

The electrolyte layer 202 contains an electrolyte material. The electrolyte material is, for example, a solid electrolyte material. The electrolyte layer 202 may be a solid electrolyte layer. The solid electrolyte material contained in the electrolyte layer 202 may contain the solid electrolyte material of embodiment 1. The solid electrolyte material contained in the electrolyte layer 202 may be composed of only the solid electrolyte material of embodiment 1.

The solid electrolyte material contained in the electrolyte layer 202 may be composed of only a solid electrolyte material different from the solid electrolyte material of embodiment 1. An example of a solid electrolyte material different from that of embodiment 1 is Li₂MgX’₄、Li₂FeX’₄、Li(Al,Ga,In)X’₄、Li₃(Al,Ga,In)X’₆Or LiI. Wherein X' is at least one element selected from F, Cl, Br and I.

The electrolyte layer 202 may contain not only the solid electrolyte material of embodiment 1 but also a solid electrolyte material different from the solid electrolyte material of embodiment 1.

The thickness of the electrolyte layer 202 may be 1 μm or more and 100 μm or less. When the thickness of the electrolyte layer 202 is 1 μm or more, the positive electrode 201 and the negative electrode 203 are less likely to be short-circuited. When the thickness of the electrolyte layer 202 is 100 μm or less, the battery can operate at high output.

The anode 203 contains a material capable of occluding and releasing metal ions (e.g., lithium ions). The negative electrode 203 contains, for example, a negative electrode active material (for example, negative electrode active material particles 205).

Examples of the negative electrode active material include a metal material, a carbon material, an oxide, a nitride, a tin compound, or a silicon compound. The metal material may be a simple metal or an alloy. Examples of the metallic material are lithium metal or lithium alloy. Examples of carbon materials are natural graphite, coke, incompletely graphitized carbon, carbon fibers, spherical carbon, artificial graphite or amorphous carbon. Preferable examples of the negative electrode active material include silicon (i.e., Si), tin (i.e., Sn), a silicon compound, and a tin compound from the viewpoint of capacity density.

The negative electrode active material may be selected according to the reduction resistance of the solid electrolyte material contained in the negative electrode 203. When the negative electrode 203 contains the solid electrolyte material according to embodiment 1, a negative electrode active material that can be used isA material capable of occluding and releasing lithium ions at 0.27V or more with respect to lithium. If the anode active material is such a material, the solid electrolyte material of embodiment 1 contained in the anode 203 can be suppressed from being reduced. As a result, the battery has high charge and discharge efficiency. Examples of such materials are titanium oxide, indium metal or lithium alloys. An example of titanium oxide is Li₄Ti₅O₁₂、LiTi₂O₄Or TiO₂。

The median diameter of the negative electrode active material particles 205 is 0.1 μm or more and 100 μm or less. When the median diameter of the negative electrode active material particles 205 is 0.1 μm or more, the negative electrode active material particles 205 and the solid electrolyte particles 100 can be formed in a good dispersion state in the negative electrode 203. This improves the charge/discharge characteristics of the battery. When the median diameter of the negative electrode active material particles 205 is 100 μm or less, the lithium diffusion rate in the negative electrode active material particles 205 increases. Thereby, the battery can operate with high output.

The median particle diameter of the anode active material particles 205 may be larger than that of the solid electrolyte particles 100. This enables the negative electrode active material particles 205 and the solid electrolyte particles 100 to be in a good dispersion state.

In the negative electrode 203, the ratio of the volume of the negative electrode active material particles 205 to the total of the volume of the negative electrode active material particles 205 and the volume of the solid electrolyte particles 100 may be 0.30 or more and 0.95 or less from the viewpoint of the energy density and output of the battery.

The electrode material 1100 shown in fig. 2 may be included in the negative electrode 202. In order to prevent the solid electrolyte particles 100 from reacting with the negative electrode active material (i.e., the electrode active material particles 206), a coating layer 216 may be formed on the surface of the electrode active material particles 206. Thus, the battery has high charge and discharge efficiency. Examples of the coating material contained in the coating layer 216 include a sulfide solid electrolyte, an oxide solid electrolyte, a polymer solid electrolyte, and a halide solid electrolyte.

In the case where the solid electrolyte particle 100 is the solid electrolyte material of embodiment 1, the coating material may be a sulfide solidA bulk electrolyte, an oxide solid electrolyte or a polymer solid electrolyte. An example of a sulfide solid electrolyte is Li₂S-P₂S₅. An example of an oxide solid electrolyte is tri-lithium phosphate. An example of the polymer solid electrolyte is a composite compound of polyethylene oxide and a lithium salt. An example of such a polymer solid electrolyte is lithium bis (trifluoromethanesulfonyl) imide.

The thickness of the negative electrode 203 may be 10 μm or more and 500 μm or less from the viewpoint of energy density and output of the battery.

At least one selected from the positive electrode 201, the electrolyte layer 202, and the negative electrode 203 may contain a solid electrolyte material different from that of embodiment 1 for the purpose of improving ion conductivity. Examples of the solid electrolyte material different from the solid electrolyte material of embodiment 1 are a sulfide solid electrolyte, an oxide solid electrolyte, a halide solid electrolyte, or an organic polymer solid electrolyte.

In the present disclosure, "sulfide solid electrolyte" refers to a sulfur-containing solid electrolyte. The "oxide solid electrolyte" refers to a solid electrolyte containing oxygen. The oxide solid electrolyte may contain anions other than oxygen (but other than sulfur anions and halogen anions). The "halide solid electrolyte" refers to a solid electrolyte containing a halogen element and containing no sulfur. The halide solid electrolyte may contain not only a halogen element but also oxygen.

An example of a sulfide solid electrolyte is Li₂S-P₂S₅、Li₂S-SiS₂、Li₂S-B₂S₃、Li₂S-GeS₂、Li_3.25Ge_0.25P_0.75S₄Or Li₁₀GeP₂S₁₂。

Examples of oxide solid electrolytes are:

(i)LiTi₂(PO₄)₃or an element substitution body thereof,

(ii)(LaLi)TiO₃such as a perovskite-type solid electrolyte,

(iii)Li₁₄ZnGe₄O₁₆、Li₄SiO₄、LiGeO₄or an element substitution body thereof,

(iv)Li₇La₃Zr₂O₁₂or an elemental substitution thereof, or

(v)Li₃PO₄Or an N-substitution thereof.

An example of a halide solid electrolyte material is Li_aMe’_bY_cZ₆The compound shown in the specification. Wherein, satisfy the following equation: a + mb +3c is 6 and c > 0. Me' is at least one selected from metallic elements and semimetallic elements other than Li and Y. Z is at least one element selected from F, Cl, Br and I. The value of m represents the valence of Me'.

"half-metal elements" are B, Si, Ge, As, Sb and Te.

The "metal element" is all elements contained in groups 1 to 12 of the periodic table (except hydrogen) and all elements contained in groups 13 to 16 of the periodic table (except B, Si, Ge, As, Sb, Te, C, N, P, O, S and Se).

Me' may be at least one element selected from Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta and Nb.

An example of a halide solid electrolyte is Li₃YCl₆Or Li₃YBr₆。

In the case where the electrolyte layer 202 contains the solid electrolyte material of embodiment 1, the anode 203 may contain a sulfide solid electrolyte material. Thereby, the solid electrolyte material and the anode active material of embodiment 1 are inhibited from contacting each other with respect to the sulfide solid electrolyte material in which the anode active material is electrochemically stable. As a result, the internal resistance of the battery decreases.

Examples of the organic polymer solid electrolyte material include a high molecular compound and a lithium salt compound. The polymer compound may have an ethylene oxide structure. The polymer compound having an ethylene oxide structure can contain a large amount of lithium salt, and thus has higher ionic conductivity.

An example of the lithium salt is LiPF₆、LiBF₄、LiSbF₆、LiAsF₆、LiSO₃CF₃、LiN(SO₂CF₃)₂、LiN(SO₂C₂F₅)₂、LiN(SO₂CF₃)(SO₂C₄F₉) Or LiC (SO)₂CF₃)₃. A lithium salt selected from these may be used alone. Alternatively, a mixture of two or more lithium salts selected from these may also be used.

At least one selected from the positive electrode 201, the electrolyte layer 202, and the negative electrode 203 may contain a nonaqueous electrolyte solution, a gel electrolyte, or an ionic liquid for the purpose of facilitating the transfer of lithium ions and improving the output characteristics of the battery.

The nonaqueous electrolytic solution contains a nonaqueous solvent and a lithium salt dissolved in the nonaqueous solvent. Examples of the nonaqueous solvent include a cyclic carbonate solvent, a chain carbonate solvent, a cyclic ether solvent, a chain ether solvent, a cyclic ester solvent, a chain ester solvent, or a fluorine solvent. Examples of the cyclic carbonate solvent are ethylene carbonate, propylene carbonate or butylene carbonate. Examples of the chain carbonate solvent are dimethyl carbonate, ethyl methyl carbonate or diethyl carbonate. Examples of cyclic ether solvents are tetrahydrofuran, 1, 4-dioxane or 1, 3-dioxolane. Examples of the chain ether solvent are 1, 2-dimethoxyethane or 1, 2-diethoxyethane. An example of a cyclic ester solvent is gamma-butyrolactone. An example of the chain ester solvent is methyl acetate. Examples of fluorosolvents are fluoroethylene carbonate, methyl fluoropropionate, fluorobenzene, fluoroethyl methyl carbonate or dimethyl fluorocarbonate. A nonaqueous solvent selected from these may be used alone. Alternatively, a mixture of two or more nonaqueous solvents selected from these may also be used.

An example of the lithium salt is LiPF₆、LiBF₄、LiSbF₆、LiAsF₆、LiSO₃CF₃、LiN(SO₂CF₃)₂、LiN(SO₂C₂F₅)₂、LiN(SO₂CF₃)(SO₂C₄F₉) Or LiC (SO)₂CF₃)₃. A lithium salt selected from these may be used alone. Alternatively, a mixture of two or more lithium salts selected from these may also be used. The concentration of the lithium salt is, for example, in the range of 0.5 mol/liter or more and 2 mol/liter or less.

As the gel electrolyte, a polymer material impregnated with a nonaqueous electrolytic solution can be used. Examples of polymeric materials are polyoxyethylene, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, or polymers with ethylene oxide groups.

Examples of cations contained in ionic liquids are:

(i) aliphatic linear quaternary salts such as tetraalkyl amines or tetraalkyl phosphonium,

(ii) aliphatic cyclic ammonium such as pyrrolidinium, morpholinium, imidazolinium, tetrahydropyrimidinium, piperazinium or piperidinium, or

(iii) Nitrogen-containing heterocyclic aromatic cations such as pyridinium or imidazolium.

An example of the anion contained in the ionic liquid is PF₆ ^-、BF₄ ^-、SbF₆ ^-、AsF₆ ^-、SO₃CF₃ ^-、N(SO₂CF₃)₂ ^-、N(SO₂C₂F₅)₂ ^-、N(SO₂CF₃)(SO₂C₄F₉)^-Or C (SO)₂CF₃)₃ ^-。

The ionic liquid may contain a lithium salt.

At least one selected from the positive electrode 201, the electrolyte layer 202, and the negative electrode 203 may contain a binder for the purpose of improving the adhesion between particles.

Examples of binders are polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, aramid resins, polyamides, polyimides, polyamideimides, polyacrylonitrile, polyacrylic acid, polymethyl acrylate, polyethyl acrylate, polyhexamethylene acrylate, polymethacrylic acid, polymethyl methacrylate, polyethyl methacrylate, polyhexamethylene methacrylate, polyvinyl acetate, polyvinylpyrrolidone, polyether, polyethersulfone, hexafluoropropylene, styrene-butadiene rubber or carboxymethylcellulose. As the binder, a copolymer may also be used. Examples of the binder include copolymers of two or more materials selected from the group consisting of tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, pentafluoropropylene, fluoromethyl vinyl ether, acrylic acid, and hexadiene. Mixtures of two or more selected from the above materials may also be used.

At least one selected from the positive electrode 201 and the negative electrode 203 may contain a conductive assistant for the purpose of improving electron conductivity.

Examples of the conductive assistant are:

(i) graphites such as natural graphites and artificial graphites,

(ii) carbon blacks such as acetylene black and ketjen black,

(iii) conductive fibers such as carbon fibers or metal fibers,

(iv) the carbon fluoride is used as a raw material,

(v) the class of metal powders such as aluminum and the like,

(vi) conductive whiskers such as zinc oxide and potassium titanate,

(vii) a conductive metal oxide such as titanium oxide, or

(viii) And a conductive polymer compound such as polyaniline, polypyrrole, or polythiophene.

For cost reduction, the conductive auxiliary agent (i) or (ii) may be used.

Examples of the shape of the battery according to embodiment 2 include coin type, cylindrical type, square type, sheet type, button type, flat type, and laminated type.

(examples)

Hereinafter, the present disclosure will be described in more detail with reference to embodiment 1 and embodiment 2.

(embodiment 1)

(sample 1-1)

[ production of solid electrolyte Material ]

In a dry atmosphere having a dew point of-30 ℃ or lower (hereinafter referred to as "dry atmosphere"), 1:1 Li is used as a raw material powder₂O:NbCl₅Molar ratio prepared Li₂O and NbCl₅. These raw material powders are pulverized and mixed during grinding to obtain a mixed powder. The resultant mixed powder was ground by a planetary ball mill at 600rpm for 24 hours. Thus, a powder of the solid electrolyte material of sample 1-1 containing a crystal phase composed of Li, Nb, O and Cl was obtained. In the solid electrolyte material of sample 1-1, the molar ratio Li/Nb is 2.0 and the molar ratio O/Cl is 0.2.

[ evaluation of ion conductivity ]

Fig. 3 shows a schematic view of a press-molding die 300 used for evaluating the ion conductivity of a solid electrolyte material.

The press mold 300 includes a frame 301, a punch lower portion 302, and a punch upper portion 303. The frame 301 is made of insulating polycarbonate. Punch upper 303 and punch lower 302 are both formed of an electronically conductive stainless steel.

The ion conductivity of the solid electrolyte material of sample 1-1 was measured by the following method using a press mold 300 shown in fig. 3.

In a dry atmosphere, the powder of the solid electrolyte material of sample 1-1 (i.e., in fig. 3, the powder 401 of the solid electrolyte material) is filled into the inside of the pressure-forming die 300. Inside the press mold 300, a pressure of 300MPa is applied to the solid electrolyte material of sample 1-1 using a punch lower portion 302 and a punch upper portion 303. Thus, an ion conductivity measuring cell of sample 1-1 was obtained.

The lower punch 302 and the upper punch 303 are connected to a potentiostat (Princeton Applied Research, VersaSTAT4) equipped with a frequency response analyzer in a state where pressure is Applied. The punch upper portion 303 is connected to the working electrode and the potential measuring terminal. The punch lower portion 302 is connected to the counter electrode and the reference electrode. The ionic conductivity of the solid electrolyte material of sample 1-1 was measured at room temperature by electrochemical impedance measurement. As a result, the ionic conductivity measured at 22 ℃ was 2.2 mS/cm.

[ evaluation of temperature stability of Ionic conductivity ]

FIG. 4 is a graph showing the temperature dependence of the ionic conductivity of the solid electrolyte material of sample 1-1. The results shown in FIG. 4 were measured by the following method.

The ion conductivity measuring unit of sample 1-1 was placed in a thermostatic bath. The ionic conductivity was measured in both the temperature-increasing and temperature-decreasing processes in the range of-30 ℃ to 80 ℃.

As shown in FIG. 4, no sharp change in ion conductivity was observed in the range of-30 ℃ to 80 ℃, and the solid electrolyte material of sample 1-1 maintained high lithium ion conductivity.

[ X-ray diffraction ]

FIG. 5 is a graph showing an X-ray diffraction pattern of the solid electrolyte material of sample 1-1. The results shown in FIG. 5 were measured by the following method.

The X-ray diffraction pattern of the solid electrolyte material of sample 1-1 was measured using an X-ray diffraction apparatus (RIGAKU, MiniFlex600) in a dry atmosphere having a dew point of-45 ℃ or lower. As the X-ray source, Cu — K α rays (wavelengths 1.5405 and 1.5444) were used.

The solid electrolyte material of sample 1-1 has diffraction peaks at 13.8 ° (i.e., 1 st range) and 24.5 ° (i.e., 2 nd range). Therefore, the solid electrolyte material of sample 1-1 contains the 1 st crystal phase having high lithium ion conductivity.

The solid electrolyte material of sample 1-1 has a diffraction peak derived from LiCl. Therefore, the solid electrolyte material of sample 1-1 also contains the 2 nd crystal phase different from the 1 st crystal phase.

[ production of Battery ]

In an argon atmosphere having a dew point of-60 ℃ or lower (hereinafter referred to as "dry argon atmosphere"), the solid electrolyte material of sample 1-1 and LiCoO as a positive electrode active material were mixed₂Preparation was performed at a volume ratio of 50: 50. These materials were mixed in a mortar to obtain a mixture.

The solid electrolyte material (100mg) of sample 1-1 and the above mixture (10.8mg) were stacked in this order in an insulating cylinder having an inner diameter of 9.5mm to obtain a laminate. A pressure of 360MPa was applied to the laminate to form a solid electrolyte layer and a positive electrode. The thickness of the solid electrolyte layer was 500 μm.

Subsequently, a Li-In alloy having a thickness of 200 μm was laminated on the solid electrolyte layer to obtain a laminate. A pressure of 80MPa was applied to the laminate to form a negative electrode.

Current collectors formed of stainless steel are attached to the positive and negative electrodes, and current collecting leads are attached to the current collectors.

Finally, the inside of the insulating cylinder is isolated from the outside atmosphere by an insulating sleeve, and the inside of the cylinder is sealed.

Thus, a battery of sample 1-1 was obtained.

[ Charge/discharge test ]

Fig. 8 is a graph showing the initial discharge characteristics of the battery of sample 1-1. The results shown in FIG. 8 were measured by the following method.

The cell of sample 1-1 was placed in a thermostatic bath at 25 ℃.

At 80. mu.A/cm²The battery of sample 1-1 was charged until a voltage of 3.6V was reached. This current density corresponds to a 0.05C rate. Then, the concentration was adjusted to 80. mu.A/cm²The cell of sample 1-1 was discharged until a voltage of 2.5V was reached. This current density corresponds to a 0.05C rate.

As a result of the charge and discharge test, the battery of sample 1-1 had an initial discharge capacity of 1.01 mAh.

(sample 1-2)

As the raw material powder, 1:1:1 Li was used₂O:NbCl₅:NbOCl₃Molar ratio prepared Li₂O、NbCl₅And NbOCl₃. Except for this, a solid electrolyte material of sample 1-2 was obtained in the same manner as in sample 1-1. In the solid electrolyte material of sample 1-2, the molar ratio Li/Nb is 1.0 and the molar ratio O/Cl is 0.25.

The ion conductivity of the solid electrolyte material of sample 1-2 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 0.65 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 1-2 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 6. The solid electrolyte material of sample 1-2 had diffraction peaks at 14.1 ° (i.e., 1 st range) and 24.0 ° (i.e., 2 nd range). In addition, the solid electrolyte material of sample 1-2 also has a diffraction peak derived from LiCl. Therefore, the solid electrolyte material of sample 1-2 contains the 1 st crystal phase and the 2 nd crystal phase.

(samples 1 to 3)

As the raw material powder, 1:2 Li was used₂O:NbCl₅Molar ratio prepared Li₂O and NbCl₅. Except for this, the solid electrolyte material of sample 1-3 was obtained in the same manner as in sample 1-1. In the solid electrolyte material of samples 1 to 3, the molar ratio Li/Nb was 1.0 and the molar ratio O/Cl was 0.1.

The ion conductivity of the solid electrolyte material of sample 1-3 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 1.4X 10^-3mS/cm。

The X-ray diffraction of the solid electrolyte material of sample 1-3 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 6. The solid electrolyte materials of samples 1 to 3 had diffraction peaks at 14.1 ° (i.e., 1 st range). In addition, the solid electrolyte materials of samples 1 to 3 also have NbCl-derived materials₅The diffraction peak of (1). Therefore, the solid electrolyte material of samples 1 to 3 contains the 1 st crystal phase and the 2 nd crystal phase.

(samples 1 to 4)

A mixed powder of the raw material powders was obtained in the same manner as in sample 1-1. The mixed powder was fired at 300 ℃ for 12 hours in an argon atmosphere. Thus, solid electrolyte materials of samples 1 to 4 were obtained. In the solid electrolyte materials of samples 1 to 4, the molar ratio Li/Nb was 2.0 and the molar ratio O/Cl was 0.20.

The ion conductivity of the solid electrolyte material of sample 1-4 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 7.0X 10^-2mS/cm。

The X-ray diffraction of the solid electrolyte material of sample 1-4 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 6. The solid electrolyte materials of samples 1 to 4 had diffraction peaks at 24.0 ° (i.e., 1 st range). In addition, the solid electrolyte materials of samples 1 to 4 also have diffraction peaks derived from LiCl. Therefore, the solid electrolyte material of samples 1 to 4 contains the 1 st crystal phase and the 2 nd crystal phase.

(samples 1 to 5)

A mixed powder of the raw material powders was obtained in the same manner as in sample 1-1. The mixed powder was ground at 300rpm for 24 hours. Thus, solid electrolyte materials of samples 1 to 5 were obtained. In the solid electrolyte materials of samples 1 to 5, the molar ratio Li/Nb was 2.0 and the molar ratio O/Cl was 0.20.

The ion conductivity of the solid electrolyte material of sample 1-5 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 0.37 mS/cm.

The X-ray diffraction of sample 1-5 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 7. The solid electrolyte materials of samples 1 to 5 had diffraction peaks at 13.3 ° (i.e., 1 st range) and 24.5 ° (i.e., 2 nd range). In addition, the solid electrolyte materials of samples 1 to 5 also have diffraction peaks derived from LiCl. Therefore, the solid electrolyte material of samples 1 to 5 contained the 1 st crystal phase and the 2 nd crystal phase.

(samples 1 to 6)

As the raw material powder, 1:1 ratio of LiOH to TaCl was used₅The molar ratio of LiOH to TaCl was prepared₅. Except for this, the solid electrolyte material of sample 1-6 was obtained in the same manner as sample 1-1. In the solid electrolyte materials of samples 1 to 6, the molar ratio Li/Ta was 1.0 and the molar ratio O/Cl was 0.25.

The ion conductivity of the solid electrolyte material of sample 1-6 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 3.0 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 1-6 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 7. The solid electrolyte materials of samples 1 to 6 had diffraction peaks at 12.9 ° (i.e., 1 st range) and 25.8 ° (i.e., 2 nd range). In addition, the solid electrolyte materials of samples 1 to 6 also have diffraction peaks derived from LiCl. Therefore, the solid electrolyte material of samples 1 to 6 contained the 1 st crystal phase and the 2 nd crystal phase.

(samples 1 to 7)

As the raw material powder, LiOH: NbCl in a ratio of 2:1:1₅:TaCl₅LiOH and NbCl were prepared in a molar ratio₅And TaCl₅. Except for this, the solid electrolyte materials of samples 1 to 7 were obtained in the same manner as in sample 1 to 1. In the solid electrolyte materials of samples 1 to 7, the molar ratio Li/(Nb, Ta) was 1.0, and the molar ratio O/Cl was 0.25.

The ion conductivity of the solid electrolyte material of sample 1-7 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 2.0 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 1-7 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 7. The solid electrolyte materials of samples 1 to 7 had diffraction peaks at 13.1 ° (i.e., 1 st range) and 25.0 ° (i.e., 2 nd range). In addition, the solid electrolyte materials of samples 1 to 7 also have diffraction peaks derived from LiCl. Therefore, the solid electrolyte material of samples 1 to 7 contained the 1 st crystal phase and the 2 nd crystal phase.

(samples 1 to 8)

As the starting powder, 1:1 LiCl: NbCl was used₅LiCl and NbCl were prepared in molar ratio₅. Except for this, the solid electrolyte materials of samples 1 to 8 were obtained in the same manner as in sample 1 to 1. In the solid electrolyte materials of samples 1 to 8, the molar ratio Li/Nb was 1.0 and the molar ratio O/Cl was 0.0.

The ion conductivity of the solid electrolyte material of sample 1 to 8 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 9.5X 10^-5mS/cm。

The X-ray diffraction of the solid electrolyte material of sample 1 to 8 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 5. The solid electrolyte materials of samples 1 to 8 have no diffraction peak in the 1 st and 2 nd ranges.

The solid electrolyte materials of samples 1-1 to 1-8 were shown in table 1 with respect to the constituent elements, the molar ratios, and the measurement results.

[ Table 1]

(examination)

As is clear from Table 1, the solid electrolyte materials of samples 1-1 to 1-7 had 1X 10-ions at room temperature³High ionic conductivity of mS/cm or more. The solid electrolyte materials of samples 1-1 to 1-7 have higher ion conductivity than the solid electrolyte materials of samples 1-8.

Comparing samples 1-2 and 1-3 with samples 1-8, it is understood that the solid electrolyte material has high ion conductivity if the molar ratio O/X is 0.1 or more and 0.25 or less. When the molar ratio O/X is 0.25, the ion conductivity is further improved as compared with the samples 1-3 in the samples 1-2.

Comparing samples 1-1, 1-2, and 1-5 to 1-7 with samples 1-3 and 1-4, it is understood that a solid electrolyte material having a peak in both the 1 st range and the 2 nd range has higher ion conductivity in the X-ray diffraction pattern than a solid electrolyte material having a peak in only one of the 1 st range and the 2 nd range.

It is understood that, when M contains Ta, the solid electrolyte material has higher ion conductivity as compared with sample 1-2 in samples 1-6 and 1-7.

As shown in fig. 4, the solid electrolyte material of sample 1-1 maintains high lithium ion conductivity in the range of the expected use temperature of the battery.

As shown in fig. 8, the battery of sample 1-1 was charged and discharged at room temperature.

(embodiment 2)

(sample 2-1)

[ production of solid electrolyte Material ]

In a dry atmosphere, 1:1 LiCl: NbOCl was used as a raw material powder₃LiCl and NbOCl were prepared in molar ratio₃. These raw material powders were pulverized and mixed in a mortar to obtain a mixed powder. The resulting mixed powder was subjected to a milling treatment at 600rpm for 24 hours using a planetary ball mill. Thus, a powder of the solid electrolyte material of sample 2-1 containing a crystal phase composed of Li, Nb, O and Cl was obtained. x and y have values of1.0 and 1.0.

[ evaluation of ion conductivity ]

The ion conductivity of the solid electrolyte material of sample 2-1 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 5.70 mS/cm.

[ evaluation of temperature stability of Ionic conductivity ]

FIG. 9 is a graph showing the temperature dependence of the ionic conductivity of the solid electrolyte material of sample 2-1. The results shown in FIG. 9 were measured in the same manner as in sample 1-1.

As shown in FIG. 9, no sharp change in the ionic conductivity was observed in the range of-30 ℃ to 80 ℃, and the solid electrolyte material of sample 2-1 maintained high lithium ion conductivity.

[ X-ray diffraction ]

FIG. 10 is a graph showing an X-ray diffraction pattern of the solid electrolyte material of sample 2-1. In the measurement of X-ray diffraction, the same experiment as in sample 1-1 was carried out.

The solid electrolyte material of sample 2-1 had a diffraction peak at 13.9 ° (i.e., 3 rd range). Therefore, the solid electrolyte material of sample 2-1 contains the 3 rd crystal phase having high lithium ion conductivity.

The solid electrolyte material of sample 2-1 also had a diffraction peak derived from LiCl. Therefore, the solid electrolyte material of sample 2-1 also contains the 4 th crystal phase different from the 3 rd crystal phase.

[ production of Battery ]

The solid electrolyte material of sample 2-1 and LiCoO as a positive electrode active material were mixed in a dry argon atmosphere₂Preparation was performed at a volume ratio of 50: 50. These materials were mixed in a mortar to obtain a mixture.

The solid electrolyte material (100mg) of sample 2-1 and the above mixture (10.6mg) were stacked in this order in an insulating cylinder having an inner diameter of 9.5mm to obtain a laminate. A pressure of 360MPa was applied to the laminate to form a solid electrolyte layer and a positive electrode. The thickness of the solid electrolyte layer was 500 μm.

In addition to the above, a battery of sample 2-1 was obtained in the same manner as in sample 1-1.

[ Charge/discharge test ]

FIG. 13 is a graph showing the initial discharge characteristics of the battery of sample 2-1. The results shown in FIG. 13 were measured by the following method.

The cell of sample 2-1 was placed in a thermostatic bath at 25 ℃.

At 80. mu.A/cm²The battery of sample 1-1 was charged until a voltage of 3.6V was reached. This current density corresponds to a 0.05C rate. Then, the concentration was adjusted to 80. mu.A/cm²The cell of sample 2-1 was discharged until a voltage of 2.5V was reached. This current density corresponds to a 0.05C rate.

As a result of the charge-discharge test, the battery of sample 2-1 had an initial discharge capacity of 1.06 mAh.

(sample 2-2)

As a starting powder, 1.1:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-2 was obtained in the same manner as in sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2-1 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 5.23 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-2 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte material of sample 2-2 has a diffraction peak at 13.9 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte material of sample 2-2 contains the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-3)

As a starting powder, 1.5:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-3 was obtained in the same manner as in sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2-3 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 3.25 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-3 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte material of sample 2-3 had a diffraction peak at 13.9 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte material of sample 2-3 contains the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-4)

As a starting powder, LiCl: NbOCl 2:1 was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-4 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2-4 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 1.73 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-4 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 4 had diffraction peaks at 14.0 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte material of samples 2 to 4 contained the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-5)

As a starting powder, 3:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-5 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2-5 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 0.44 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-5 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 5 had diffraction peaks at 14.0 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte material of samples 2 to 5 contained the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-6)

As a starting powder, 4:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Removing deviceIn a manner similar to that of sample 2-1, a solid electrolyte material of sample 2-6 was obtained.

The ion conductivity of the solid electrolyte material of sample 2-6 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 0.25 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-6 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 6 had diffraction peaks at 13.7 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 6 contained the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-7)

As a starting powder, 5:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-7 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2 to 7 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 0.12 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-7 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 7 had diffraction peaks at 13.4 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 7 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 8)

As a starting powder, 6:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-8 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2 to 8 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 8.06X 10^-2mS/cm。

The X-ray diffraction of the solid electrolyte material of sample 2 to 8 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 8 had diffraction peaks at 14.1 ° (i.e., 3 rd range). Therefore, the solid electrolyte material of samples 2 to 8 contained the 3 rd crystal phase.

(sample 2-9)

As a starting powder, 0.9:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-9 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2 to 9 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 5.60 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2-9 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 9 had diffraction peaks at 13.8 ° (i.e., 3 rd range). Therefore, the solid electrolyte material of samples 2 to 9 contained the 3 rd crystal phase.

(sample 2-10)

As a starting powder, 0.8:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-10 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 10 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 2.83 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2 to 10 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 10 had diffraction peaks at 13.8 ° (i.e., 3 rd range). Therefore, the solid electrolyte material of samples 2 to 10 contained the 3 rd crystal phase.

(samples 2 to 11)

As a starting powder, 0.5:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-11 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of sample 2 to 11 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 1.20 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2 to 11 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 11 had diffraction peaks at 13.8 ° (i.e., 3 rd range). Therefore, the solid electrolyte material of samples 2 to 11 contained the 3 rd crystal phase.

(samples 2 to 12)

As a starting powder, 0.3:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-12 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 13 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 0.16 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2 to 12 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 12 had diffraction peaks at 13.8 ° (i.e., 3 rd range). Therefore, the solid electrolyte material of samples 2 to 12 contained the 3 rd crystalline phase.

(samples 2 to 13)

As a starting powder, 0.2:1 LiCl: NbOCl was used₃LiCl and NbOCl were prepared in molar ratio₃. Except for this, a solid electrolyte material of sample 2-13 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 13 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 3.29X 10^-2mS/cm。

The X-ray diffraction of the solid electrolyte material of samples 2 to 13 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 10. The solid electrolyte materials of samples 2 to 13 had diffraction peaks at 13.9 ° (i.e., 3 rd range). Therefore, the solid electrolyte materials of samples 2 to 13 contained the 3 rd crystal phase.

(samples 2 to 14)

As the raw material powder, 0.5:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-14 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 14 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 7.70 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 14 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 14 had diffraction peaks at 13.9 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 14 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 15)

As the raw material powder, LiCl/Li in a ratio of 0.5:0.25:1 was used₂O:NbOCl₃LiCl and Li were prepared in a molar ratio₂O and NbOCl₃. Except for this, a solid electrolyte material of sample 2-15 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 15 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 1.75 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2 to 15 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 15 had diffraction peaks at 14.0 ° (i.e., 3 rd range). Therefore, the solid electrolyte materials of samples 2 to 15 contained the 3 rd crystal phase.

(samples 2 to 16)

As the raw material powder, 1.6:1 of LiOH: NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-16 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 16 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 0.16 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 16 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 16 had diffraction peaks at 12.7 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 16 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 17)

As the raw material powder, 1.8:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-17 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 17 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 5.86X 10^-2mS/cm。

The X-ray diffraction of the solid electrolyte material of samples 2 to 17 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 17 had diffraction peaks at 12.3 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 17 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 18)

As the raw material powder, 0.9:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-18 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 18 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 8.60 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 18 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 18 had diffraction peaks at 13.9 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was observed. Therefore, the solid electrolyte materials of samples 2 to 18 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 19)

As the raw material powder, 0.8:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, the solid electrolyte material of sample 2-19 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 19 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 3.85 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 19 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 19 had diffraction peaks at 14.0 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 19 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 20)

As the raw material powder, 0.7:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-20 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 20 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 1.26 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 20 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 20 had diffraction peaks at 14.1 ° (i.e., 3 rd range). In addition, also from LiCl and NbCl₅The diffraction peak of (1). Therefore, the solid electrolyte materials of samples 2 to 20 contained the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-21)

As the raw material powder, 0.6:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-21 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 21 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 0.10 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 21 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 21 had diffraction peaks at 14.2 ° (i.e., 3 rd range). In addition, also from LiCl and NbCl₅The diffraction peak of (1). Therefore, the solid electrolyte materials of samples 2 to 21 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 22)

As the raw material powder, 0.5:1 ratio of LiOH to NbCl was used₅LiOH and NbCl were prepared in molar ratio₅. Except for this, a solid electrolyte material of sample 2-22 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 22 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 1.61X 10^-4mS/cm。

The X-ray diffraction of the solid electrolyte material of samples 2 to 22 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 11. The solid electrolyte materials of samples 2 to 22 had diffraction peaks at 14.0 ° (i.e., 3 rd range). In addition, also from LiCl and NbCl₅The diffraction peak of (1). Therefore, the solid electrolyte materials of samples 2 to 22 contained the 3 rd crystal phase and the 4 th crystal phase.

(sample 2-23)

As a raw material powder, 1:1 ratio of LiOH to NbBr was used₅The molar ratio of LiOH to NbBr was prepared₅. Except for this, a solid electrolyte material of sample 2-23 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 23 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 0.40 mS/cm.

The X-ray diffraction of the solid electrolyte material of sample 2 to 23 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 12. The solid electrolyte materials of samples 2 to 23 had diffraction peaks at 13.0 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiBr was also observed. Therefore, the solid electrolyte materials of samples 2 to 23 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 24)

As the raw material powder, LiOH: NbCl in a ratio of 1:0.5:0.5 was used₅:NbBr₅LiOH and NbCl were prepared in a molar ratio₅And NbBr₅. Except for this, a solid electrolyte material of sample 2-24 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 24 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 0.87 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 24 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 12. The solid electrolyte materials of samples 2 to 24 had diffraction peaks at 13.3 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was observed. Therefore, the solid electrolyte materials of samples 2 to 24 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 25)

As the raw material powder, 1:1 ratio of LiOH to TaCl was used₅The molar ratio of LiOH to TaCl was prepared₅. Except for this, a solid electrolyte material of sample 2-25 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 25 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 5.20 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 25 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 12. The solid electrolyte materials of samples 2 to 25 had diffraction peaks at 12.8 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 25 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 26)

As the raw material powder, 0.9:1 ratio of LiOH to TaCl was used₅The molar ratio of LiOH to TaCl was prepared₅. Except for this, a solid electrolyte material of sample 2-26 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 26 was measured in the same manner as in sample 1 to 1. As a result, the ionic conductivity measured at 22 ℃ was 7.68 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 26 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 12. The solid electrolyte materials of samples 2 to 26 had diffraction peaks at 14.4 ° (i.e., 3 rd range). Therefore, the solid electrolyte materials of samples 2 to 26 contain the 3 rd crystal phase.

(samples 2 to 27)

As the raw material powder, 1:1 Li was used₂O:TaCl₅Molar ratio prepared Li₂O and TaCl₅. Otherwise, a solid electrolyte of sample 2-27 was obtained in the same manner as in sample 2-1A material.

The ion conductivity of the solid electrolyte material of samples 2 to 27 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 1.40 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 27 was measured in the same manner as in sample 1-1. The measurement results are shown in FIG. 12. The solid electrolyte materials of samples 2 to 27 had diffraction peaks at 15.3 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiCl was also observed. Therefore, the solid electrolyte materials of samples 2 to 27 contained the 3 rd crystal phase and the 4 th crystal phase.

(samples 2 to 28)

As a raw material powder, 1:1 ratio of LiOH to TaBr was used₅The molar ratio of LiOH to TaBr was prepared₅. Except for this, a solid electrolyte material of sample 2 to 28 was obtained in the same manner as sample 2-1.

The ion conductivity of the solid electrolyte material of samples 2 to 28 was measured in the same manner as in sample 1-1. As a result, the ionic conductivity measured at 22 ℃ was 0.33 mS/cm.

The X-ray diffraction of the solid electrolyte material of samples 2 to 28 was measured in the same manner as in sample 1 to 1. The measurement results are shown in FIG. 12. The solid electrolyte materials of samples 2 to 28 had diffraction peaks at 12.5 ° (i.e., 3 rd range). In addition, the diffraction peak derived from LiBr was also observed. Therefore, the solid electrolyte materials of samples 2 to 28 contained the 3 rd crystal phase and the 4 th crystal phase.

The types of elements M and X, the values of X and y, and the measurement results of the solid electrolyte materials of samples 2-1 to 2-22 are shown in Table 2. The types of elements M and X, the values of X and y, and the measurement results of the solid electrolyte materials of samples 2-23 to 2-28 are shown in Table 3.

[ Table 2]

[ Table 3]

(examination)

As is clear from tables 2 and 3, the solid electrolyte materials of samples 2-1 to 2-28 had a density of 1X 10 at room temperature^-4High ionic conductivity of mS/cm or more. The solid electrolyte materials of samples 2-1 to 2-28 have higher ion conductivity than the solid electrolyte materials of samples 1-8.

As is clear from comparison of samples 2-1 to 2-4 and 2-9 to 2-11 with samples 2-5 to 2-8, 2-12 and 2-13, the solid electrolyte material has higher ion conductivity if the value of x is 0.5 or more and 2.0 or less. As is clear from comparison of samples 2-1 to 2-3, 2-9 and 2-10 with samples 2-4 to 2-8, 2-12 and 2-13, the ion conductivity is further improved when the value of x is 0.8 or more and 1.5 or less. As is clear from comparison of samples 2-1, 2-2 and 2-9 with samples 2-3 and 2-10, the ion conductivity is further improved when the value of x is 0.9 or more and 1.1 or less.

Comparing samples 2-1, 2-14, and 2-16 to 2-19, it is found that when the value of x is equal to the value of y, the solid electrolyte material has higher ion conductivity if the values of x and y are 0.8 or more and 1.0 or less.

It is understood that when samples 2-1 and 2-24 are compared with samples 2-23 or when samples 2-25 are compared with samples 2-28, the solid electrolyte material has higher ion conductivity when X contains Cl.

Comparing samples 2-1, 2-4, 2-18, and 2-23 with samples 2-25, 2-27, 2-26, and 2-28, it is understood that the solid electrolyte material has higher ion conductivity in the case where M contains Nb.

The solid electrolyte material of sample 2-1 maintained high lithium ion conductivity in the range of the expected use temperature of the battery.

The battery of sample 2-1 was charged and discharged at room temperature.

As described above, the solid electrolyte material of the present disclosure has high lithium ion conductivity and is therefore suitable for providing a battery having excellent charge and discharge characteristics.

Industrial applicability

The solid electrolyte material of the present disclosure is useful, for example, for an all-solid lithium ion secondary battery.

Description of the reference numerals

100 solid electrolyte plasmid

201 positive electrode

202 electrolyte layer

203 negative electrode

204 positive electrode active material particle

205 negative electrode active material particle

206 electrode active material particle

216 coating layer

300 compression molding die

301 framework

Lower part of 302 punch press

303 upper part of punch press

401 powder of solid electrolyte material

1000 cell

1100 electrode material