Electrode body

Abstract

To easily vent gas inside an electrode body to the outside.SOLUTION: An electrode body 1 includes a first current collector 10, a first mixture layer 20, a second current collector 30, a second mixture layer 40, and a separator 50. The first mixture layer 20 is provided on the first current collector 10. The second mixture layer 40 is provided on the second current collector 30. The separator 50 is disposed between the first mixture layer 20 and the second mixture layer 40. The second mixture layer 40 includes a groove portion 41. The groove portion 41 extends along the surface direction of the first mixture layer 20. A ventilation portion 100 is formed at a position in contact with the groove portion 41.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an electrode body.

Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-357836) discloses a battery including an electrode body. The battery includes an element in which a positive electrode and a negative electrode are overlapped with each other via a separator, and the separator is adhered to the positive electrode and the negative electrode via an adhesive layer. A groove whose end reaches the end side of the electrode is formed on the composite material surface of the positive electrode to which the separator is adhered via the adhesive layer. Patent Document 1 describes that since the solvent volatilized from the adhesive layer for adhering the separator to the electrode is quickly discharged to the outside through the groove formed on the composite material surface of the electrode, the solvent does not remain inside the battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] With the use and deterioration of the battery, gas may be generated due to side reactions in the composite material layer of the electrode body. The gas may inhibit the battery reaction by remaining in the composite material layer.

[0005] In the electrode body disclosed in Patent Document 1, the gas generated on the negative electrode side when viewed from the separator cannot pass through the groove formed in the positive electrode composite material layer on the opposite side. Therefore, the gas generated inside this electrode body may be difficult to be discharged to the outside.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide an electrode body capable of easily discharging gas generated inside the electrode body to the outside.

Means for Solving the Problems

[0007] (1) An electrode body according to an aspect of the present disclosure includes a first current collector, a first composite layer, a second current collector, a second composite layer, and a separator. The first composite layer is provided on the first current collector. The second composite layer is provided on the second current collector. The separator is disposed between the first composite layer and the second composite layer. The second composite layer has a groove portion extending along the surface direction of the first composite layer. A ventilation portion is formed at a position in contact with the groove portion.

[0008] According to the configuration of (1) above, by providing the groove portion, the ventilation portion can be easily formed as described above. Then, the gas generated inside the electrode body can be easily discharged to the outside through the ventilation portion.

[0009] (2) In the configuration of (1) above, the groove portion may be provided such that the second current collector is exposed toward the separator side.

[0010] According to the configuration of (2) above, the cross-sectional area of the groove portion becomes larger in the extending direction of the groove portion. As a result, the gas flow path in the ventilation portion can be enlarged.

[0011] (3) In the configuration of (2) above, the first composite layer may be a negative electrode composite layer, and the second composite layer may be a positive electrode composite layer.

[0012] According to the configuration of (3) above, even when the groove portion is provided such that the second current collector is exposed toward the separator side, it is possible to suppress the prevention of metals such as metallic lithium in the second current collector.

[0013] (4) In any one of the configurations of (1) to (3) above, the separator may have a first ventilation portion as a ventilation portion through which gas can flow from the first composite layer side to the second composite layer side.

[0014] According to the configuration of (4) above, the gas retained in the first composite material layer moves to the groove portion through the first ventilation portion. The gas that has moved to the groove portion can further move along the groove portion. Therefore, the gas generated in the first composite material layer can be easily discharged to the outside.

[0015] (5) In the configuration of (4) above, the separator may be composed of a plurality of divided separators arranged side by side in the plane direction of the first composite material layer. Each end of the plurality of divided separators may be arranged at a position corresponding to the groove portion. The first ventilation portion may be the ends of the plurality of divided separators, and may be configured such that gas can flow from the first composite material layer side through between these ends to the second composite material layer side. According to the configuration of (5) above, the first ventilation portion can be easily formed.

[0016] (6) In the configuration of (5) above, the ends of the plurality of divided separators may overlap each other.

[0017] According to the configuration of (6) above, since the ends overlap each other, even when the separator has the first ventilation portion, a short circuit between the first composite material layer and the second composite material layer or the second current collector can be suppressed.

[0018] (7) In any one of the configurations of (4) to (6) above, the groove portion may linearly extend along the plane direction of the first composite material layer. The first ventilation portion may form a slit extending along the groove portion.

[0019] According to the configuration of (7) above, the gas flow in the groove portion is likely to become a flow along the linearly extending direction of the groove portion. Therefore, the direction of gas flow in the groove portion is stabilized. At the same time, the cross-sectional area of the flow path in the first ventilation portion can be greatly expanded.

[0020] (8) In any one of the configurations (1) to (3) above, a second ventilation part may be formed as the ventilation part. The second ventilation part may be composed of a first part disposed at a position corresponding to the groove part in the separator and a second part which is a part of the first combined material layer facing the first part. The second ventilation part may be configured such that gas can flow between the first part and the second part along the extending direction of the groove part.

[0021] According to the configuration of (8) above, the gas staying in the first combined material layer can move along the extending direction of the groove part in the second ventilation part. Therefore, the gas generated in the first combined material layer can be easily discharged.

[0022] (9) In the configuration of (8) above, the separator may be composed of a plurality of divided separators arranged side by side in the plane direction of the first combined material layer. The ends of the plurality of divided separators may form the first part while overlapping each other.

[0023] According to the configuration of (9) above, at least one of the ends is easily separated from the first combined material layer. Therefore, it is easy to secure a gap between the first part and the second part, and gas can flow more easily in the second ventilation part.

[0024] (10) In the configuration of (9) above, the groove part may be provided such that the second current collector is exposed toward the separator side. One of the ends of the plurality of divided separators may be welded to the second current collector.

[0025] According to the configuration of (10) above, the gas flow path in the second ventilation part can be formed more stably.

[0026] (11) In the configuration of (6) or (9) above, a part of the overlapping parts of the ends of the plurality of divided separators may be welded to each other.

[0027] According to the configuration of (11) above, even when the separator is composed of a plurality of divided separators, the above welding can suppress the short circuit between the first composite layer and the second composite layer or the second current collector through the ends.

Advantages of the Invention

[0028] According to the present disclosure, the gas generated inside the electrode body can be easily discharged to the outside.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0030] Hereinafter, the electrode body according to each embodiment of the present disclosure will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[0031] (Embodiment 1) FIG. 1 is a plan view showing an electrode body according to Embodiment 1. FIG. 2 is a partial cross-sectional view of the electrode body of FIG. 1 seen in the direction of the arrow of line II-II.

[0032] As shown in FIGS. 1 and 2, the electrode body 1 includes a first current collector 10, a first composite layer 20, a second current collector 30, a second composite layer 40, and a separator 50. And, in the electrode body 1, a plurality of ventilation portions 100 are formed.

[0033] The electrode body 1 according to the present disclosure may be an electrode body 1 used in a battery such as a non-aqueous electrolyte secondary battery. The electrode body 1 may be used in the battery in a wound state. A plurality of electrode bodies 1 may be used in the battery in a stacked state with each other. The electrode body 1 may be used in the battery in a zigzag folded state.

[0034] The electrode body 1 may be housed, for example, in a case (not shown) filled with an electrolytic solution or a laminate film (not shown). Thereby, a power storage cell or a power storage device including the electrode body 1 and the case or the laminate film may be manufactured. The power storage cell or the power storage device may be mounted on a vehicle.

[0035] As shown in FIGS. 1 and 2, the first current collector 10 extends in a planar shape. The first current collector 10 has an outer shape in the form of a plate, a sheet, or a foil. In the present embodiment, the first current collector 10 is in the form of a foil. When viewed from a direction orthogonal to the surface direction of the first current collector 10, the first current collector 10 has a rectangular outer shape.

[0036] The first current collector 10 is formed of metal. In the present embodiment, the first current collector 10 is formed of copper.

[0037] The first composite material layer 20 is provided on the first current collector 10. The first composite material layer 20 extends in a planar shape along the surface direction of the first current collector 10. When viewed from a direction orthogonal to the surface direction of the first composite material layer 20, the first composite material layer 20 has a rectangular outer shape. The outer shape of the first composite material layer 20 follows the outer shape of the first current collector 10.

[0038] In the present embodiment, the first composite material layer 20 is a negative electrode composite material layer. The negative electrode composite material layer contains a negative electrode active material, a binder, and the like. Examples of the negative electrode active material include graphite and the like.

[0039] The second current collector 30 extends substantially parallel to the first current collector 10. The second current collector 30 and the first current collector 10 have a plate-like, sheet-like, or foil-like outer shape. In the present embodiment, the first current collector 10 is foil-like. When viewed from a direction orthogonal to the plane direction of the second current collector 30, the outer edge of the second current collector 30 substantially overlaps with the outer edge of the first current collector 10. The outer shape of the second current collector 30 has a substantially rectangular outer shape.

[0040] The second current collector 30 is formed of metal. In the present embodiment, the second current collector 30 is formed of aluminum or an aluminum alloy.

[0041] The second composite material layer 40 is provided on the second current collector 30. The second composite material layer 40 extends in a planar shape along the plane direction of the first composite material layer 20. When viewed from a direction orthogonal to the plane direction of the first composite material layer 20, the outer edge of the second composite material layer 40 is located inside the outer edge of the first composite material layer 20. Thereby, when the electrode body 1 is used in a lithium-ion battery or the like, precipitation of metallic lithium on the first current collector 10 can be suppressed.

[0042] As shown in FIG. 1, in the present embodiment, the second composite material layer 40 has a plurality of groove portions 41. The plurality of groove portions 41 extend along the plane direction of the first composite material layer 20. Specifically, the plurality of groove portions 41 linearly extend along the plane direction of the first composite material layer 20. Thereby, the flow of gas in the groove portion 41 tends to be a flow along the linearly extending direction of the groove portion 41. Therefore, the direction in which the gas flows in the groove portion 41 becomes stable. The flow of gas in the groove portion 41 will be described later.

[0043] In FIG. 1, as the plane direction of the first composite material layer 20, a first direction D1 and a second direction D2 are shown. The second direction D2 is a direction orthogonal to the first direction D1. The plurality of groove portions 41 extend parallel to the second direction D2. The plurality of groove portions 41 extend from one edge to the other edge of the second composite material layer 40 in the second direction D2.

[0044] As shown in FIG. 2, in the present embodiment, the plurality of groove portions 41 are provided such that the second current collector 30 is exposed toward the separator 50 side in each of the plurality of groove portions 41. As a result, the cross-sectional area of the groove portion 41 becomes larger in the extending direction of the groove portion 41.

[0045] The second composite material layer 40 has a plurality of divided second composite material layers 40D. The plurality of divided second composite material layers 40D are arranged in the first direction D1. A pair of adjacent divided second composite material layers 40D are arranged with the groove portion 41 therebetween.

[0046] However, the groove portion 41 does not necessarily have to be provided such that the second current collector 30 is exposed by the groove portion 41. In other words, the groove portion 41 may have a concave groove outer shape that opens at least toward the separator 50 side.

[0047] It is preferable that only one first composite material layer 20 is provided for the plurality of divided second composite material layers 40D described above. Thereby, the energy density of the electrode body 1 can be improved. Further, it is preferable that no groove or the like is formed in the first composite material layer 20 such that the first current collector 10 is exposed at a position corresponding to the groove portion 41. Thereby, the energy density of the electrode body 1 can be improved.

[0048] In the present embodiment, the second composite material layer 40 is a positive electrode composite material layer. Thereby, even when the groove portion 41 is provided such that the second current collector 30 is exposed toward the separator 50 side, precipitation of a metal such as metallic lithium in the second current collector 30 can be suppressed. The positive electrode composite material layer contains a positive electrode active material, a binder, and the like. Examples of the positive electrode active material include LiCoO2, LiNo2, LiMn2O4, and the like. Note that the first composite material layer 20 may be a positive electrode composite material layer and the second composite material layer 40 may be a negative electrode composite material layer.

[0049] As shown in FIG. 2, the separator 50 is disposed between the first composite material layer 20 and the second composite material layer 40. The separator 50 separates the first current collector 10 and the first composite material layer 20 from the second current collector 30 and the second composite material layer 40. The separator 50 is made of an insulating material. The separator 50 may be a porous membrane. In the present embodiment, the separator 50 has minute voids that allow the permeation of ions such as lithium ions.

[0050] A plurality of first vent portions 110 are formed in the separator 50 as a plurality of vent portions 100. The first vent portions 110 are configured such that gas can flow from the first composite material layer 20 side to the second composite material layer 40 side. A plurality of first vent portions 110 are formed at positions corresponding to the respective plurality of groove portions 41. The first vent portions 110 form slits extending along the corresponding groove portions 41. Thereby, the cross-sectional area of the flow path in the first vent portions 110 can be greatly increased. The specific configuration of the slit will be described later.

[0051] In the present embodiment, the separator 50 is composed of a plurality of divided separators 50D. The plurality of divided separators 50D are arranged side by side in the plane direction of the first composite material layer 20. Specifically, the plurality of divided separators 50D are arranged side by side in the first direction D1. The end portions of the plurality of divided separators 50D adjacent to each other in the first direction D1 overlap each other.

[0052] Next, a pair of adjacent divided separators 50A and 50B among the plurality of divided separators 50D will be described. A pair of divided separators 50D other than these pair of divided separators 50A and 50B may also have the same configuration as the pair of divided separators 50A and 50B.

[0053] In this embodiment, the end portions 52A and 52B of each of the plurality of divided separators 50A and 50B are arranged at positions corresponding to the groove portion 41. In this embodiment, the first ventilation portion 110 is specifically the end portions 52A and 52B of the plurality of divided separators 50A and 50B. The first ventilation portion 110 is configured such that gas can flow from the first composite material layer 20 side through between these end portions 52A and 52B to the second composite material layer 40 side. Thereby, the first ventilation portion 110 can be easily formed. The slit formed by the first ventilation portion 110 is the gap between the end portions 52A and 52B. Note that the separator 50 may be formed of one member. When the separator 50 is formed of one member, the slit formed by the first ventilation portion 110 may be a through hole penetrating the separator 50.

[0054] In this embodiment, the end portions 52A and 52B are positioned so as to overlap the groove portion 41 in a direction orthogonal to the plane direction of the first composite material layer 20. Thereby, even if the width of the groove portion 41 decreases due to the volume change of the second composite material layer 40, it is possible to suppress the short circuit between the first composite material layer 20 and the second composite material layer 40. Note that the edges of the end portions 52A and 52B may be arranged flush with both end edges of the groove portion 41 in the first direction D1, respectively.

[0055] The end portions 52A and 52B of the plurality of divided separators 50A and 50B overlap each other. By overlapping the end portions 52A and 52B in this way, even when the separator 50 has the first ventilation portion 110, it is possible to suppress the short circuit between the first composite material layer 20 and the second composite material layer 40 or the second current collector. Further, by overlapping the end portions 52A and 52B with each other, at least one of the end portions 52A and 52B is easily separated from the first composite material layer 20. However, the end portions 52A and 52B of the plurality of divided separators 50A and 50B may face each other in the first direction D1.

[0056] The overlapping portions of the plurality of divided separators 50A and 50B are preferably located in the central region CA of the groove portion 41. Thereby, even if manufacturing errors occur in the dimensions of the plurality of divided separators 50A and 50B, it is possible to prevent either one of the end portions 52A and 52B of the divided separators 50A and 50B from being unable to be disposed in the groove portion 41. The central region CA of the groove portion 41 is a region excluding the two regions OA on both sides when the groove portion 41 is divided into four regions in the first direction D1. Note that the overlapping portions of the plurality of divided separators 50A and 50B may be in other regions OA other than the central region CA of the groove portion 41.

[0057] A part of the overlapping portions of the end portions 52A and 52B of the plurality of divided separators 50A and 50B may be welded to each other. Thereby, even when the separator 50 is composed of the plurality of divided separators 50A and 50B, the above welding can prevent the first composite material layer 20 and the second composite material layer 40 or the second current collector 30 from being short-circuited to each other through the space between the end portions 52A and 52B. However, a part of the end portions 52A and 52B of the plurality of divided separators 50A and 50B may be provided with non-welded portions. Thereby, in the overlapping portions of the plurality of divided separators 50A and 50B, gas can flow from the first composite material layer 20 side through the space between the end portions 52A and 52B to the second composite material layer 40 side.

[0058] In the electrode body 1, the number of the plurality of divided separators 50D may be the same as the number of the plurality of divided second composite material layers 40D. Thereby, it is possible to easily form the plurality of first vent portions 110 so as to correspond to the plurality of groove portions 41 one by one. As a result, it is possible to finely discharge gas (details will be described later) at a plurality of locations via the groove portion 41 and the first vent portion 110. The number of the plurality of divided separators 50D may be different from the number of the plurality of divided second composite material layers 40D.

[0059] Furthermore, in the electrode body 1 according to the present embodiment, a second ventilation portion 120 is formed as the ventilation portion 100. The second ventilation portion 120 is composed of a first portion 121 disposed at a position corresponding to the groove portion 41 in the separator 50 and a second portion 122 which is a portion of the first composite layer 20 facing the first portion 121. The second ventilation portion 120 is configured such that gas can flow between the first portion 121 and the second portion 122 along the extending direction of the groove portion 41. Specifically, the second ventilation portion 120 is configured such that gas can flow between the first portion 121 and the second portion 122 along the second direction D2.

[0060] In the present embodiment, the ends 52A and 52B of the plurality of divided separators 50A and 50B overlap each other and constitute the first portion 121. Specifically, the first portion 121 is the first ventilation portion 110.

[0061] As described above, in the electrode body 1 according to the present embodiment, both the first ventilation portion 110 and the second ventilation portion 120 are formed as the ventilation portion 100. However, only one of the first ventilation portion 110 and the second ventilation portion 120 may be formed.

[0062] For example, when no gap is formed between the separator 50 and the first composite layer 20, the second ventilation portion 120 is not formed. However, even in such a case, the ends 52A and 52B of the plurality of divided separators 50A and 50B constituting the first ventilation portion 110 face each other in the first direction D1, so that the first ventilation portion 110 can be formed. Also, in the above case, the separator 50 may be formed of a single member, and the first ventilation portion 110 may be formed by forming the above-described slit penetrating the separator 50.

[0063] Further, for example, when the ends 52A and 52B of the divided separators 50A and 50B are entirely welded to each other along the second direction D2, the first ventilation portion 110 is not formed. Even in such a case, the second ventilation portion 120 can be formed because the ends 52A of the divided separators 50A and 50B overlap each other.

[0064] Next, the gas flow path when gas is generated in the first composite material layer 20 of the electrode body 1 will be described. FIG. 3 is a partial cross-sectional view of the electrode body schematically showing the gas generated inside the electrode body according to Embodiment 1. In FIG. 3, it is shown in the same cross-sectional view as FIG. 2. In FIG. 3, the gas G generated in the first composite material layer 20 is shown. Also, the moving direction of the gas G is schematically shown by the arrow attached to the gas G.

[0065] As shown in FIG. 3, the gas G generated in the first composite material layer 20 stays between the separator 50 and the first composite material layer 20. Specifically, it stays between the first portion 121 and the second portion 122 in the second ventilation portion 120. Then, the gas G further moves to the groove portion 41 through between the end portions 52A and 52B in the first ventilation portion 110. The gas G that has moved to the groove portion 41 moves along the second direction D2 (see FIG. 1). Then, the gas G can be discharged to the outside of the electrode body 1 from either one end in the second direction D2 of the groove portion 41.

[0066] Furthermore, the gas G that is generated in the first composite material layer 20 and continues to stay between the first portion 121 and the second portion 122 in the second ventilation portion 120 also moves in the direction along the groove portion 41. That is, the gas G between the first portion 121 and the second portion 122 also moves along the second direction D2 (see FIG. 1). Then, the gas G can also be discharged to the outside of the electrode body 1 from either one end in the second direction D2 of the gap between the first portion 121 and the second portion 122.

[0067] As described above, in the electrode body 1 according to Embodiment 1 of the present disclosure, the ventilation portion 100 is formed at a position in contact with the groove portion 41.

[0068] According to the above configuration, by providing the groove portion 41, the ventilation portion 100 can be easily formed. And the gas generated inside the electrode body 1 can be easily discharged to the outside by the ventilation portion 100.

[0069] Further, the separator 50 has, as a ventilation part 100, a first ventilation part 110 through which gas can flow from the first composite material layer 20 side to the second composite material layer 40 side.

[0070] According to the above configuration, the gas staying in the first composite material layer 20 moves to the groove part 41 through the first ventilation part 110. The gas that has moved to the groove part 41 can further move along the groove part 41. Therefore, the gas generated in the first composite material layer 20 can be easily discharged to the outside.

[0071] Furthermore, in the electrode body 1, as the ventilation part 100, a second ventilation part 120 is formed. The second ventilation part 120 is composed of a first part 121 disposed at a position corresponding to the groove part 41 in the separator 50 and a second part 122 that is a part of the first composite material layer 20 facing the first part 121. The second ventilation part 120 is configured such that gas can flow between the first part 121 and the second part 122 along the extending direction of the groove part 41.

[0072] According to the above configuration, the gas staying in the first composite material layer 20 can move along the extending direction of the groove part 41 within the second ventilation part 120. Therefore, the gas generated in the first composite material layer 20 can be easily discharged.

[0073] (Embodiment 2) Next, the electrode body according to Embodiment 2 will be described. The electrode body according to Embodiment 2 has a split separator that is different from the split separators 50A and 50B of the electrode body 1 according to Embodiment 1. Note that descriptions of the same configurations and effects as those of the electrode body 1 according to Embodiment 1 will not be repeated.

[0074] FIG. 4 is a partial cross-sectional view of the electrode body according to Embodiment 2. In FIG. 4, the electrode body 1a of Embodiment 2 is illustrated in a cross-sectional view similar to the cross-sectional view of the electrode body 1 of Embodiment 1 in FIG. 2.

[0075] As shown in Fig. 4, one of the ends 52Aa and 52Ba of the plurality of divided separators 50A and 50B is welded to the second current collector 30. According to this configuration, a short circuit between the first composite layer 20 and the second current collector 30 can be further suppressed. Also, the gas flow path in the second ventilation part 120 can be formed more stably. In the present embodiment, the end 52Ba is welded to the second current collector 30. The end 52Aa may also be partially welded to the second current collector 30.

[0076] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of reference numerals

[0077] 1, 1a electrode body, 10 first current collector, 20 first composite layer, 30 second current collector, 40 second composite layer, 40D divided second composite layer, 41 groove part, 50 separator, 50A, 50B, 50D divided separator, 52A, 52Aa, 52B, 52Ba end, 100 ventilation part, 110 first ventilation part, 120 second ventilation part, 121 first part, 122 second part, G gas.

Claims

1. A first current collector, a first composite material layer provided on the first current collector, a second current collector, a second composite material layer provided on the second current collector, and a separator disposed between the first composite material layer and the second composite material layer, wherein the second composite material layer has a groove portion extending along the plane direction of the first composite material layer, and a ventilation portion is formed at a position in contact with the groove portion. An electrode body.

2. The electrode body according to claim 1, wherein the groove portion is provided such that the second current collector is exposed toward the separator side.

3. The electrode body according to claim 2, wherein the first composite material layer is a negative electrode composite material layer, and the second composite material layer is a positive electrode composite material layer.

4. The electrode body according to claim 1, wherein the separator has a first ventilation portion through which gas can flow from the first composite material layer side to the second composite material layer side as the ventilation portion.

5. The separator is composed of a plurality of divided separators arranged side by side in the plane direction of the first composite material layer, ends of each of the plurality of divided separators are arranged at positions corresponding to the groove portion, and the first ventilation portion is formed by the ends of the plurality of divided separators, and the gas is configured to flow from the first composite material layer side through between these ends to the second composite material layer side. The electrode body according to claim 4.

6. The electrode body according to claim 5, wherein the ends of the plurality of divided separators overlap each other.

7. The groove portion extends linearly along the plane direction of the first composite material layer, and the first ventilation portion forms a slit extending along the groove portion. The electrode body according to claim 4.

8. A second ventilation portion is formed as the ventilation portion and is composed of a first portion disposed at a position corresponding to the groove portion of the separator and a second portion which is a portion of the first composite material layer facing the first portion, and the second ventilation portion is configured such that gas can flow between the first portion and the second portion along the extending direction of the groove portion. The electrode body according to claim 1.

9. The separator is composed of a plurality of divided separators arranged side by side in the plane direction of the first composite material layer, and the ends of the plurality of divided separators overlap each other and constitute the first portion. The electrode body according to claim 8.

10. The groove portion is provided such that the second current collector is exposed toward the separator side. The electrode body according to claim 9, wherein one of the ends of the plurality of divided separators is welded to the second current collector.

11. The electrode body according to claim 6 or claim 9, wherein a part of the overlapping portions of the ends of the plurality of divided separators are welded to each other.

Images