阅读说明：本技术 电池单元、电池模块以及电池组 (Battery unit, battery module, and battery pack ) 是由 安藤翔 于 2021-06-03 设计创作，主要内容包括：本发明提供电池单元、电池模块以及电池组,可提高安全性。电池单元(10)包括二次电池(11)、第1捕集部(12)和第2捕集部(13)。二次电池(11)具有电池壳体(11a)和电解液,所述电池壳体(11a)具备气体排出阀(11a1),所述电解液被收容于电池壳体(11a)。第1捕集部(12)由在电池壳体(11a)的外侧以覆盖气体排出阀(11a1)的方式与气体排出阀(11a1)相对的网状材料构成。第2捕集部(13)是在第1捕集部(12)的更外侧以覆盖气体排出阀(11a1)的方式与气体排出阀(11a1)相对的由难燃材料构成的液体保持材料。电池模块(100)包括多个二次电池(11)、约束构件(102)和汇流条(104),电池组(200)包括封装壳体(202)和1个或多个电池模块(100)。(The invention provides a battery unit, a battery module and a battery pack, which can improve safety. The battery unit (10) includes a secondary battery (11), a1 st trap part (12), and a 2 nd trap part (13). A secondary battery (11) is provided with a battery case (11a) and an electrolyte, wherein the battery case (11a) is provided with a gas discharge valve (11a1), and the electrolyte is contained in the battery case (11 a). The first trap part (12) is made of a mesh material that faces the gas discharge valve (11a1) so as to cover the gas discharge valve (11a1) on the outside of the battery case (11 a). The 2 nd trap part (13) is a liquid holding material made of a flame-retardant material and facing the gas discharge valve (11a1) so as to cover the gas discharge valve (11a1) further outside the 1 st trap part (12). The battery module (100) includes a plurality of secondary batteries (11), a constraining member (102), and bus bars (104), and the battery pack (200) includes a package case (202) and 1 or more battery modules (100).)

1. A battery cell, wherein,

the battery cell includes a secondary battery, a1 st trap part and a 2 nd trap part,

the secondary battery has a battery case provided with a gas discharge valve, and an electrolyte contained in the battery case,

the 1 st trap part is formed of a mesh material that faces the gas discharge valve so as to cover the gas discharge valve on the outside of the battery case,

the 2 nd trap part is a liquid holding material made of a flame retardant material, which faces the gas discharge valve so as to cover the gas discharge valve, further outside the 1 st trap part.

2. The battery cell of claim 1,

the aperture ratio of the 1 st collecting portion is 25% or more and 75% or less.

3. The battery cell according to claim 1 or 2,

the 2 nd trap part is formed of any one of a sponge, a plush material, diatomaceous earth, and a fibrous material.

4. The battery cell according to any one of claims 1 to 3,

the 1 st trap part is separated from the gas discharge valve.

5. The battery cell according to any one of claims 1 to 4,

the 2 nd trap part is provided separately from the 1 st trap part.

6. The battery cell according to any one of claims 1 to 5,

the 1 st trap portion is supported by the battery case or the 2 nd trap portion.

7. The battery cell according to any one of claims 1 to 6,

the 2 nd trap portion is supported by the 1 st trap portion or the battery case.

8. A battery module, wherein,

the battery module includes a restraining member, bus bars, a1 st trapping part, a 2 nd trapping part, and a plurality of secondary batteries,

the plurality of secondary batteries each have a battery case, an electrolytic solution, a positive electrode terminal and a negative electrode terminal,

the battery case is provided with a gas discharge valve,

the electrolyte is contained in the battery case,

the positive terminal is disposed at a side surface of the battery case,

the negative terminal is disposed at a side surface of the battery case,

the restraining member is a member that restrains the plurality of secondary batteries in a predetermined configuration,

the bus bar connects the positive electrode terminal and the negative electrode terminal between a plurality of secondary batteries,

the 1 st trap part is formed of a mesh material that faces the gas discharge valve so as to cover the gas discharge valve on the outside of the battery case of each of the plurality of secondary batteries,

the 2 nd trap part is a liquid holding material made of a flame retardant material that faces the gas discharge valve so as to cover the gas discharge valve on the outer side of the 1 st trap part of each of the plurality of secondary batteries.

9. The battery module of claim 8,

the aperture ratio of the 1 st collecting portion is 25% or more and 75% or less.

10. The battery module according to claim 8 or 9,

the 2 nd trap part is formed of any one of a sponge, a plush material, diatomaceous earth, and a fibrous material.

11. The battery module according to any one of claims 8 to 10,

the 1 st trap part is provided separately from the gas discharge valve of each of the plurality of secondary batteries.

12. The battery module according to any one of claims 8 to 11,

the 2 nd trap part is provided separately from the 1 st trap part.

13. The battery module according to any one of claims 8 to 12,

the 1 st trap part is supported by at least one of any of the battery cases of the plurality of secondary batteries, the restraining member, the bus bar, and the 2 nd trap part.

14. The battery module according to any one of claims 8 to 13,

the 2 nd trap portion is supported by at least one of any of the battery cases of the plurality of secondary batteries, the 1 st trap portion, the restraint member, and the bus bar.

15. A battery pack, wherein,

the battery pack includes:

1 or more battery modules according to any one of claims 8 to 12, respectively; a package case housing the 1 or more battery modules in a predetermined configuration.

16. The battery pack according to claim 15,

the 1 st trap part is supported by at least one of any of the battery cases of the plurality of secondary batteries, the restraint member, the bus bar, the package case, and the 2 nd trap part.

17. The battery pack according to claim 15 or 16,

the 2 nd trap part is supported by at least one of any of the battery cases of the plurality of secondary batteries, the restraint member, the bus bar, the package case, and the 1 st trap part.

Technical Field

The invention relates to a battery cell, a battery module and a battery pack.

Background

Japanese patent laid-open No. 2017-091762 discloses a cell structure in which a trapping filter of an electrode material and an electrolyte absorbing material are provided just below a safety valve provided at an upper portion of a battery cell inside a battery cell case. Here, the electrolyte absorbing material is disposed between the trapping filter and the safety valve. In this publication, even when the safety valve is opened, the battery cell can prevent the electrolyte present outside the electrode body from scattering to the outside of the case.

Japanese patent application laid-open No. 2008-117765 discloses a battery pack in which a battery is housed in a case and which has a path through which gas discharged from the battery flows. In this battery pack, the temperature of the gas is reduced by the passage and the gas is discharged to the outside. The path includes a bent portion that turns the gas flow direction. Therefore, when a spark is generated from the gas, the direction of the flow of the gas and the direction of the discharge of the spark can be separated at the bent portion. As a result, the gas can be suppressed from flowing with the spark, and the gas can be suppressed from reaching combustion. Further, it is disclosed that a spark trapping portion (Japanese: spark トラップ portion) is provided in the path.

The exhaust duct (1C) of the battery pack disclosed in this publication includes a connecting pipe (1H), a main pipe (1I), a gas cooling unit (1L), a spark collecting unit (1M), and an exhaust port (1P). This structure is shown in, for example, fig. 1 to 3 of the publication. The reference numerals in parentheses denote the reference numerals in this publication. The spark collecting section (1M) is disposed adjacent to the gas cooling section (1L). As the spark collecting section (1M), it is disclosed that a porous ceramic plate, a gel sheet, a copper mesh, an aluminum mesh, an SUS mesh, a cement plate or a gypsum plate is provided on the inner wall surface to collect sparks in the gas. In the battery pack disclosed in this publication, gas discharged from the battery is guided from the connecting pipe portion (1H) to the main pipe portion (1I), passes through the main pipe portion (1I), then passes through the gas cooling portion (1L), then passes through the spark collecting portion (1M), and is discharged to the outside of the case through the exhaust port (1P).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-

Patent document 2: japanese patent laid-open No. 2008-117765

Disclosure of Invention

Problems to be solved by the invention

In addition, a battery pack in which a plurality of secondary batteries are combined can be used as a driving power source for a vehicle that is intended to have a high output. The plurality of secondary batteries are connected by bus bars (japanese: バスバー) to constitute a battery module. In addition, a plurality of battery modules may be accommodated in the package case to constitute a battery pack. In a battery pack in which a plurality of battery modules are housed, it is desired to improve safety against a plurality of batteries in the battery pack that are linked to cause thermal runaway of 1 cell as a starting point.

Means for solving the problems

The battery cell disclosed herein includes a secondary battery, a1 st trap part, and a 2 nd trap part. The secondary battery has a battery case provided with a gas discharge valve, and an electrolyte contained in the battery case. The 1 st trap part is made of a mesh material that faces the gas discharge valve so as to cover the gas discharge valve on the outside of the battery case. The 2 nd trap part is a liquid holding material made of a nonflammable material (japanese: nonflammable material) facing the gas discharge valve so as to cover the gas discharge valve further outside the 1 st trap part.

In this battery cell, the 1 st trap part and the 2 nd trap part can suppress scattering of the electrolyte and the spark contained in the gas discharged when the gas discharge valve is opened. Therefore, safety against the occurrence of thermal runaway in a chain manner can be improved.

From the viewpoint of improving safety, the aperture ratio of the 1 st trap part may be, for example, 25% or more and 75% or less. The 2 nd collecting part may be made of any one of a sponge, a plush material (Japanese: ウール material), diatomaceous earth, and a fiber material. The 1 st trap part may be separate from the gas discharge valve. The 2 nd trap part may be provided separately from the 1 st trap part. The 1 st trap portion may be supported by the battery case or the 2 nd trap portion. The 2 nd trap portion may be supported by the 1 st trap portion or the battery case.

The battery module disclosed herein includes a restraint member, a bus bar, a1 st trapping part, a 2 nd trapping part, and a plurality of secondary batteries. The plurality of secondary batteries each have a battery case, an electrolyte, a positive electrode terminal, and a negative electrode terminal, the battery case is provided with a gas discharge valve, the electrolyte is contained in the battery case, the positive electrode terminal is provided on a side surface of the battery case, and the negative electrode terminal is provided on a side surface of the battery case. The restraining member is a member that restrains the plurality of secondary batteries in a predetermined configuration. The bus bar connects the positive terminal and the negative terminal between the plurality of secondary batteries. The 1 st trap part is formed of a mesh material that faces the gas discharge valve so as to cover the gas discharge valve on the outer side of the battery case of each of the plurality of secondary batteries. The 2 nd trap part is a liquid holding material made of a flame retardant material facing the gas discharge valve so as to cover the gas discharge valve on the outer side of the 1 st trap part of each of the plurality of secondary batteries.

In this battery module, the 1 st trap part and the 2 nd trap part can suppress scattering of the electrolyte and the spark contained in the gas discharged when the gas discharge valve is opened. Therefore, it is possible to improve safety against the thermal runaway occurring in the other secondary batteries of the battery module in a chain manner with the thermal runaway of 1 secondary battery as a starting point.

Here, the aperture ratio of the 1 st collecting portion may be 25% or more and 75% or less. The 2 nd collecting part may be formed of any one of a sponge, a plush material, diatomaceous earth, and a fibrous material. The 1 st trap part may be provided separately from the gas discharge valves of the plurality of secondary batteries. The 2 nd trap part may be provided separately from the 1 st trap part. The 1 st trap part may be supported by at least one of any of the battery cases of the plurality of secondary batteries, the restraining member, the bus bar, and the 2 nd trap part. The 2 nd collecting portion may be supported by at least one of any of the battery cases of the plurality of secondary batteries, the 1 st collecting portion, the constraining member, and the bus bar.

The battery pack disclosed herein may include 1 or more battery modules and a package case that accommodates the 1 or more battery modules in a predetermined configuration. The 1 st collecting portion may be supported by at least one of any of the battery cases of the plurality of secondary batteries, the restraining member, the bus bar, the package case, and the 2 nd collecting portion. The 2 nd collecting portion may be supported by at least one of any of the battery cases of the plurality of secondary batteries, the restraining member, the bus bar, the package case, and the 1 st collecting portion.

With this battery pack, scattering of electrolyte and sparks contained in gas discharged when the gas discharge valve is opened can be suppressed by the 1 st trap and the 2 nd trap. Therefore, it is possible to improve safety against the thermal runaway of 1 secondary battery being a starting point for the other secondary batteries in the battery module to be caused in a chain manner.

Drawings

Fig. 1 is a schematic diagram illustrating a battery cell 10 disclosed herein.

Fig. 2 is a schematic diagram showing the battery module 100.

Fig. 3 is a schematic diagram showing the battery pack 200.

Detailed Description

One embodiment of the battery cell, the battery module, and the battery pack disclosed herein is described below. The embodiments described herein are, of course, not intended to limit the invention specifically. The present invention is not limited to the embodiments described herein unless otherwise specified.

Battery unit 10

Fig. 1 is a schematic diagram illustrating a battery cell 10 disclosed herein. As shown in fig. 1, the battery unit 10 includes a secondary battery 11, a1 st trap part 12, and a 2 nd trap part 13.

Secondary battery 11

The secondary battery 11 includes a battery case 11a and an electrolyte. The secondary battery 11 may be, for example, a nonaqueous electrolyte secondary battery. In the secondary battery 11, an electrode body and an electrolyte solution are housed inside a battery case 11 a. The battery case 11a is provided with a gas discharge valve 11a 1. In the present embodiment, the battery case 11a is a so-called rectangular case made of a substantially rectangular parallelepiped case. A positive electrode terminal 21 and a negative electrode terminal 22 are mounted on the battery case 11 a.

Gas discharge valve 11a1

The gas discharge valve 11a1 is designed such that: when a large amount of gas is generated in the battery case 11a and the internal pressure rises, the gas discharge valve 11a1 is broken and opened before other portions of the battery case 11 a. When the internal pressure of the battery case 11a rises to a certain extent, the gas-discharge valve 11a1 of the battery case 11a opens. This suppresses the internal pressure of the battery case 11a from rising to a certain level or more.

Battery module 100

Fig. 2 is a schematic diagram showing the battery module 100. Fig. 3 is a schematic diagram showing the battery pack 200. In fig. 2, the 1 st collecting part 12 and the 2 nd collecting part 13 are not shown. As shown in fig. 2, the battery module 100 includes a plurality of secondary batteries 11, a constraining member 102, and bus bars 104.

Each of the plurality of secondary batteries 11 constituting the battery module 100 has a battery case 11a, and the battery case 11a is provided with a gas discharge valve 11a 1. Although not shown, the electrode body and the electrolyte are housed in the battery case 11 a. The battery case 11a is provided with a positive electrode terminal 21 and a negative electrode terminal 22, respectively. In the battery module 100, as shown in fig. 2, a plurality of secondary batteries 11 are arranged. In the embodiment shown in fig. 2, each of the plurality of secondary batteries 11 has a rectangular battery case 11 a. The plurality of secondary batteries 11 are rectangular battery cases 11a arranged so that their wide surfaces face each other.

The battery case 11a is provided with a gas discharge valve 11a1 on one side surface. The plurality of secondary batteries 11 are arranged in a state in which the orientation of the battery case 11a is aligned so that the gas discharge valves 11a1 are oriented in the same direction. Although not shown, a separator may be disposed between the plurality of secondary batteries 11. The separator may have a function of forming a flow path for the refrigerant or insulating heat between the secondary batteries 11.

The restraining member 102 restrains the plurality of secondary batteries 11 of the battery module 100. In the form shown in fig. 2, the restraining member 102 has restraining plates 102a, 102b that are overlapped at both ends of the arranged plurality of secondary batteries 11. Restraint bands 102c are provided on the restraint plates 102a and 102 b. By applying tension to the restraint band 102c, a predetermined restraint pressure is applied to the plurality of secondary batteries 11 constituting the battery module 100.

The bus bar 104 electrically connects the positive terminal 21 and the negative terminal 22 between the plurality of secondary batteries 11 of the battery module 100. In other words, the bus bars 104 electrically connect the plurality of secondary batteries 11 of the battery module 100. The plurality of secondary batteries 11 of the battery module 100 may be connected in series, for example.

Battery pack 200

The battery pack 200 includes a package housing 202 and 1 or more battery modules 100, and the package housing 202 accommodates 1 or more battery modules 100 in a predetermined configuration. The package housing 202 may be a housing having a desired mechanical strength. In the package case 202, a cooling device such as a cooling fan, a refrigerant circulation device, a control device for controlling charging and discharging of the battery modules 100 in the battery pack 200, sensors for acquiring current values, voltage values, temperatures, and the like of the battery modules 100 in the battery pack 200, and the like may be appropriately housed.

Here, the gas discharge valve 11a1 is designed to: when a large amount of gas is generated in the battery case 11a and the internal pressure rises, the gas discharge valve 11a1 is broken and opened before other portions of the battery case 11 a. When the gas discharge valve 11a1 is opened, gas may be forcibly ejected from the gas discharge valve 11a 1. When the gas discharge valve 11a1 is opened, heat generation of the secondary battery 11 may be accompanied. Therefore, the gas discharged from the gas discharge valve 11a1 may contain volatilized electrolyte. The electrolyte contained in the ejected gas may be atomized. Various flame retardant measures have been taken with respect to the electrolyte. However, from the viewpoint of improving safety, it is desirable to suppress the electrolyte discharged from the gas-discharge valve 11a1 from scattering in the case of the battery pack.

Further, as for the factor of gas generation in the battery case 11a, it is assumed that a sharp metal piece penetrates into the battery or the like at the time of vehicle collision. As a test assuming such a phenomenon, for example, a nail penetration test in which a nail is inserted into a battery may be used. In the nail penetration test, a nail is inserted into the battery case 11a so as to penetrate the electrode body. In the spike test, the positive electrode and the negative electrode of the electrode assembly housed inside the battery case 11a are short-circuited. Therefore, a spike test can be used as a test for intentionally short-circuiting the positive electrode and the negative electrode of the electrode assembly housed inside. On the other hand, in a state where the secondary battery 11 is sufficiently charged, a large potential difference exists between the positive electrode and the negative electrode. In a phenomenon involving a short circuit between the positive electrode and the negative electrode having a large potential difference, rapid heat generation due to the short circuit may be assumed, and gas may be rapidly generated in the battery case 11 a. Therefore, the spike test can be performed in an overcharged state of the battery (for example, a state in which the SOC is 100% or more). Here, SOC means State of Charge.

Various structures have been proposed for stopping the reaction associated with the short circuit by melting the separator of the secondary battery 11 sandwiched between the positive electrode and the negative electrode and closing the opening, for example, with respect to the heat generation of the secondary battery 11. In addition, although the case where a flame-retardant solvent is used as the electrolyte solution has been examined, here, even if gas is generated suddenly in the battery case 11a due to a short circuit between the positive electrode and the negative electrode of the electrode assembly housed in the battery case 11a, the gas discharge valve 11a1 is opened, and therefore the battery case 11a is not damaged greatly. On the other hand, when the gas discharge valve 11a1 is opened, a large amount of gas is generated in the battery case 11a, and the internal pressure rises. Therefore, the gas is forcibly discharged from the gas discharge valve 11a 1. The gas is ejected together with the electrolyte. In addition, when a short circuit occurs inside the battery case 11a, sparks may be generated. Therefore, the gas discharged from the gas discharge valve 11a1 is not necessarily accompanied by sparks.

The 1 st trap part 12

The 1 st trap 12 faces the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 on the outside of the battery case 11 a. The 1 st trap 12 is made of a mesh material. Therefore, the 1 st trap part 12 may be configured to allow the passage of the gas and to trap the spark when the gas is accompanied by the spark. In order to achieve such a function, for example, the aperture ratio of the 1 st trap part 12 may be adjusted.

Here, the opening ratio of the 1 st trap part 12 may be set to a level that allows smooth discharge of the gas and traps sparks in the case where the gas accompanies sparks. From this viewpoint, the inventors can set the aperture ratio of the 1 st trap part 12 to, for example, 25% or more, preferably 40% or more. The aperture ratio of the first trap part 12 may be, for example, 75% or less, and preferably 60% or less. The first collecting section 12 is not limited to the lattice-shaped mesh material. For example, a mesh material in a hexagonal lattice shape may be used. The aperture ratio of the 1 st collecting section 12 can be defined as the ratio of the area of the opening to the entire net. Further, the 1 st trap 12 may be configured to allow the gas to be discharged from the gas discharge valve 11a1 and to trap sparks when sparks are included in the gas discharged from the gas discharge valve 11a 1. From this viewpoint, the 1 st collecting part 12 can be selected from an appropriate mesh material. The opening ratio, thickness, and the like of the mesh material used in the 1 st collecting part 12 are not limited unless otherwise specified.

Here, for example, a metal mesh can be used for the 1 st collecting part 12. In this case, for example, a mesh of metal such as aluminum, copper, stainless steel, brass, and inconel may be used. In addition, a mesh material made of heat-resistant ceramics may be used for the 1 st trap part 12.

In addition, the 1 st trap part 12 may be provided so as not to prevent the gas discharge valve 11a1 of the battery case 11a from being opened. For example, the 1 st trap 12 may be provided separately from the gas discharge valve 11a1 to such an extent that the opening of the gas discharge valve 11a1 is not hindered. For example, the 1 st trap part 12 may be supported by the battery case 11 a. Specifically, the positive electrode terminal and the negative electrode terminal provided in the battery case 11a may be attached.

As shown in fig. 2, in the battery module 100, the 1 st trap 12 may be opposed to the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 on the outside of the battery case 11a of each of the plurality of secondary batteries 11 in the battery module 100. In this case, the 1 st collecting part 12 may be made of a mesh material. The 1 st trap 12 may be provided separately from the gas discharge valves 11a1 of the plurality of secondary batteries 11. When the gas discharge valve 11a1 of each of the plurality of secondary batteries 11 is opened, the 1 st trap 12 does not interfere with the gas discharge valve 11a 1.

In the battery module 100, the 1 st trap part 12 may be supported by at least one of the battery case 11a, the constraining member 102, and the bus bar 104. That is, the 1 st trap part 12 may be supported by the constraining member 102, the bus bar 104, or the like, instead of being supported only by the battery case 11 a. As shown in fig. 3, in the battery pack 200, the 1 st collecting part 12 may be further attached to the package case 202.

In the present embodiment, the 1 st trap 12 is provided separately from the gas discharge valve 11a 1. The 1 st trap part 12 does not necessarily have to be separated from the gas discharge valve 11a1 unless otherwise mentioned. For example, the 1 st trap 12 may be in contact with the gas discharge valve 11a1 in the initial state. In this case, the 1 st trap 12 may include a configuration that is deformed by being pressed by the gas discharge valve 11a1 when the gas discharge valve 11a1 is opened. In this respect, in the battery module 100, the 1 st trap part 12 may be partially in contact with any of the gas discharge valves 11a1 of the plurality of secondary batteries 11 in the battery module 100.

The 2 nd trap part 13

The 2 nd trap 13 faces the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 further outside the 1 st trap 12. The 2 nd trap 13 is a liquid holding material made of a flame retardant material. The 2 nd trap 13 may be, for example, a sponge, a plush material, diatomaceous earth, a fibrous material, or the like. The 2 nd trap part 13 is provided separately from the 1 st trap part 12. The 2 nd trap 13 may be supported by the 1 st trap 12 or the battery case 11a, for example.

In the embodiment shown in fig. 1, the 1 st collecting portion 12 and the 2 nd collecting portion 13 are respectively attached to a support structure 14 attached to the battery case 11 a. The 1 st trap 12 is separated from the gas discharge valve 11a1 by a predetermined distance. The 2 nd trap part 13 may be separated from the 1 st trap part 12 by a predetermined distance. In the present embodiment, the 1 st trap 12 is disposed above the gas discharge valve 11a1 at a distance of 2cm from the gas discharge valve 11a 1. The 2 nd trap 13 is disposed above the gas discharge valve 11a1 at a distance of 4cm from the gas discharge valve 11a 1. The distance K1 from the gas discharge valve 11a1 to the 1 st trap part 12 and the distance K2 from the gas discharge valve 11a1 to the 2 nd trap part 13 are not limited to the illustrated distances and may be changed as appropriate. In this respect, in the battery module 100 as well, the 2 nd trap part 13 may be provided separately from the 1 st trap part 12 (see fig. 3).

For example, in the present embodiment, a gap S1 is left between the 1 st collecting portion 12 and the 2 nd collecting portion 13. In this case, the gas discharged from the gas discharge valve 11a1 passes through the 1 st trap 12 and is discharged from the gap S1 between the 1 st trap 12 and the 2 nd trap 13. Therefore, the gas smoothly escapes from the gas-discharge valve 11a 1. The 2 nd collecting portion 13 and the 1 st collecting portion 12 are disposed in close proximity to each other with a gap S1 therebetween. Therefore, the mist of the electrolyte solution contained in the gas passing through the 1 st trap part 12 is trapped by the 2 nd trap part 13. In this respect, the gap S1 between the 1 st collecting element 12 and the 2 nd collecting element 13 may be approximately 5mm or more and 30mm or less.

In the present embodiment, the 2 nd collecting portion 13 is provided separately from the 1 st collecting portion 12. The 2 nd trap part 13 does not necessarily have to be separated from the 1 st trap part 12 as long as it is not specifically mentioned. For example, in order to allow the gas passing through the 1 st trap part 12 to escape, the gas may be discharged to the outside through a gap between the 2 nd trap part 13 and the 1 st trap part 12. From this viewpoint, the 2 nd collecting part 13 may be in contact with the 1 st collecting part 12 in the initial state. The 2 nd collecting part 13 may partially contact the 1 st collecting part 12. In the battery module 100, the gas discharged from the gas discharge valve 11a1 and passing through the 1 st trap part 12 in each of the plurality of secondary batteries 11 in the battery module 100 can pass through the gap between the 2 nd trap part 13 and the 1 st trap part 12 and be discharged to the outside. In this respect, the 1 st trap part 12 and the 2 nd trap part 13 may have a desired gap therebetween. The 2 nd trap 13 may partially contact any 1 st trap 12 of the plurality of secondary batteries 11 in the battery module 100. Further, a spacer for maintaining the gap may be disposed between the 1 st collecting portion 12 and the 2 nd collecting portion 13. In this case, although not shown, the separator may be provided with a passage through which the gas escapes to the outside.

In the battery module 100, the 2 nd trap part 13 may be supported by at least one of any of the battery cases 11a of the plurality of secondary batteries 11, the restraining member 102, the bus bar 104, and the 1 st trap part 12. That is, the 2 nd trap part 13 may be supported by the constraining member 102, the bus bar 104, the 1 st trap part 12, and the like, instead of being supported only by the battery case 11 a. As shown in fig. 3, in the battery pack 200, the 2 nd trap part 13 may be further attached to the package case 202.

In the case where the 2 nd collecting part 13 is supported by any one of the battery case 11a, the constraining member 102, the bus bar 104, and the package case 202, the 1 st collecting part 12 may be supported by the 2 nd collecting part 13. In addition, as shown in fig. 3, when a plurality of battery modules 100 are housed in the battery pack 200, the 1 st collecting part 12 and the 2 nd collecting part 13 of the battery pack 200 may be provided for each battery module 100. When the battery pack 200 houses a plurality of battery modules 100, the 1 st collecting part 12 and the 2 nd collecting part 13 of the battery pack 200 may be members provided in 1 number for each of the plurality of battery modules 100.

As described above, the battery unit 10 disclosed herein includes the secondary battery 11, the 1 st trap part 12, and the 2 nd trap part 13, as shown in fig. 1. The secondary battery 11 includes a battery case 11a and an electrolyte, the battery case 11a includes a gas discharge valve 11a1, and the electrolyte is contained in the battery case 11 a. The 1 st trap 12 is made of a mesh material that faces the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 on the outside of the battery case 11 a. The 2 nd trap 13 is a liquid holding material made of a flame retardant material facing the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 further outside the 1 st trap 12.

In the battery cell 10, the 1 st trap part 12 and the 2 nd trap part 13 can suppress scattering of the electrolyte and sparks contained in the gas discharged when the gas discharge valve 11a1 is opened. Therefore, safety against the occurrence of thermal runaway in a chain manner can be improved.

As shown in fig. 2 and 3, the battery module 100 disclosed herein includes a constraining member 102, a bus bar 104, a1 st collecting portion 12, a 2 nd collecting portion 13, and a plurality of secondary batteries 11. Each of the plurality of secondary batteries 11 has a battery case 11a, an electrolyte solution, a positive electrode terminal 21, and a negative electrode terminal 22, the battery case 11a includes a gas discharge valve 11a1, the electrolyte solution is contained in the battery case 11a, the positive electrode terminal 21 is provided on a side surface of the battery case 11a, and the negative electrode terminal 22 is provided on a side surface of the battery case 11 a. The restraining member 102 is a member that restrains the plurality of secondary batteries 11 in a predetermined configuration. The bus bar 104 connects the positive terminal 21 and the negative terminal 22 between the plurality of secondary batteries 11. The 1 st trap 12 is made of a mesh material that faces the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 on the outside of the battery case 11a of each of the plurality of secondary batteries 11. The 2 nd trap 13 is a liquid holding material made of a flame retardant material that faces the gas discharge valve 11a1 so as to cover the gas discharge valve 11a1 on the outer side of the 1 st trap 12 of each of the plurality of secondary batteries 11.

In the battery module 100, the 1 st trap part 12 and the 2 nd trap part 13 can suppress scattering of the electrolyte and sparks contained in the gas discharged when the gas discharge valve 11a1 is opened. Therefore, safety is improved in that thermal runaway occurs in the other secondary batteries 11 of the battery module 100 in a chain manner starting from the thermal runaway of 1 secondary battery 11.

In addition, the battery pack 200 disclosed herein may include a package case 202 and 1 or more battery modules 100, as shown in fig. 3, the package case 202 accommodating 1 or more battery modules 100 in a predetermined configuration. The 1 st trap part 12 may be supported by at least one of any of the battery cases 11a of the plurality of secondary batteries 11, the restraint member 102, the bus bar 104, the package case 202, and the 2 nd trap part 13. The 2 nd trap part 13 may be supported by at least one of the battery case 11a, the constraining member 102, the bus bar 104, the package case 202, and the 1 st trap part 12, which are arbitrary ones of the battery cases 11a of the plurality of secondary batteries 11.

In the assembled battery 200, the scattering of the electrolyte and sparks contained in the gas discharged when the gas discharge valve 11a1 is opened can be suppressed by the 1 st trap part 12 and the 2 nd trap part 13. Therefore, in the assembled battery 200, safety against thermal runaway occurring in the other secondary batteries 11 in the assembled battery 200 in a chain manner with the thermal runaway of 1 secondary battery 11 as a starting point is improved.

For example, the effects of the battery cell 10, the battery module 100, and the battery pack 200 disclosed herein can be confirmed by, for example, the following abuse tests.

For example, 5-cell modules as shown in fig. 2 were produced. Then, a thermal interlock test triggered by a short circuit of the central single body was performed by inserting a nail into the central single body.

Here, in a thermal interlocking test by a barbed nail, a nail having an axis diameter of 6mm and a tip angle of 60 degrees was prepared. Here, the nail was made of SUS 440C. The battery case 11a is made of aluminum and is adapted to be pierced with nails. In the nail penetration test, the speed of the nail was set to 2 mm/sec. Here, two or more types of battery cells having different structures of the electrolyte solution and the electrode body may be prepared. Further, the starting SOC (State of Charge) is set to 100%. The conditions for charging to SOC 100% may be predetermined for each of the two cells.

In this case, the test can be performed when the 1 st collecting element 12 and the 2 nd collecting element 13 are not provided, when only the 1 st collecting element 12 is provided, and when the 1 st collecting element 12 and the 2 nd collecting element 13 are provided. A mesh material made of, for example, stainless steel may be used for the 1 st trap part 12. For example, glass wool may be used for the 2 nd trap 13.

According to the findings obtained by the present inventors, the effects of the case where both the 1 st trap part 12 and the 2 nd trap part 13 are provided can be confirmed by such tests. According to the findings obtained by the present inventors, when both the 1 st trap part 12 and the 2 nd trap part 13 are provided, it is confirmed that scattering of the electrolytic solution contained in the gas ejected from the central cell which becomes a trigger is suppressed to be small and heat generation in the chain of the battery module 100 is suppressed or delayed as compared with the other cases. Here, the longer the time before the occurrence of the interlocking heat generation of the battery module 100, and the more suppressed the interlocking heat generation of the battery module 100, the higher the safety of the battery cell 10 and the battery module 100 is evaluated.

In the above, various battery cells, battery modules, and battery packs disclosed herein have been described. Unless otherwise mentioned, the embodiments of the battery cell, the battery module, and the battery pack, and the like, which are exemplified herein, do not limit the present invention.

Description of the reference numerals

10. A battery cell; 11. a secondary battery; 11a, a battery case; 11a1, gas vent valve; 12. the 1 st trap part; 13. a 2 nd trap part; 14. a support structure; 21. a positive terminal; 22. a negative terminal; 100. a battery module; 102. a binding member; 102a, 102b, a restraint plate; 102c, a restraining band; 104. a bus bar; 200. a battery pack; 202. a package housing; s1, clearance.