Laminated electrode assembly and power storage module

Abstract

The invention relates to a laminated electrode body and a power storage module. The laminated electrode body includes a plurality of electrodes and a plurality of separators. The electrodes and the separators are alternately stacked in the first direction. The laminated electrode body extends in a second direction perpendicular to the first direction. The laminated electrode body further includes a peripheral surface extending in the second direction. The length of each separator in a third direction perpendicular to the first and second directions is longer than the length of each electrode in the third direction. The peripheral surface has first and second main surfaces on the first direction side, and first and second side surfaces on the third direction side, the first and second side surfaces being continuous with the first and second main surfaces, respectively. The separators are welded over the entire length of the laminated electrode body in the first direction on at least one of the first side surface and the second side surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a stacked electrode body and a power storage module. BACKGROUND

[0002] Conventionally, a power storage module is known. In Japanese Patent Application Publication No. 2012-209054, an electrode stack (stacked electrode body) of a stacked battery as a power storage module is disclosed. The electrode stack is formed by stacking a plurality of electrodes each disposed between separators. In the electrode stack, a separator joining portion that joins a plurality of separators stacked together is provided at a plurality of positions around the electrodes. The plurality of positions are positions that restrict movement of the electrodes in a direction that intersects with a stacking direction of the electrode stack. SUMMARY

[0003] In Japanese Patent Application Publication No. 2012-209054, the positions of the separator joining portion with respect to the stacking direction of the electrode stack are the same positions as the separators provided at the lower end or the middle portion in the stacking direction. A part of each separator other than the separators provided at the lower end or the middle portion extends from each outer edge of the positive electrode and the negative electrode stacked together to the separator joining portion. Thus, in Japanese Patent Application Publication No. 2012-209054, a space that does not contribute to charge and discharge increases from the outer edges of each positive electrode and each negative electrode stacked together to the separator joining portion.

[0004] The present disclosure provides a stacked electrode body that can prevent positional deviation of each separator and suppress a space that does not contribute to charge and discharge.

[0005] According to an aspect of the present disclosure, a stacked electrode body includes a plurality of electrodes and a plurality of separators. Each electrode and each separator are alternately stacked in a first direction. The stacked electrode body extends in a second direction that is perpendicular to the first direction. The stacked electrode body further includes a peripheral surface that extends in the second direction. A length of each separator in a third direction that is perpendicular to the first direction and the second direction is longer than a length of each electrode in the third direction. The peripheral surface has a first main surface on the first direction side and a second main surface, and a first side surface and a second side surface on the third direction side that are continuous with the first main surface and the second main surface, respectively. In at least one of the first side surface and the second side surface, each separator is welded over an entire length of the stacked electrode body in the first direction.

[0006] According to the above structure, in at least one of the first side surface and the second side surface, each separator is welded over the entire length of the stacked electrode body in the first direction. Thus, movement of each separator in the third direction within the stacked electrode body is restricted. Thus, positional deviation of each separator can be prevented. Furthermore, according to the above structure, an excess amount by which each separator exceeds an outer edge of each electrode can be suppressed. Thus, a space that does not contribute to charge and discharge can be suppressed.

[0007] Preferably, the separators are fused to each other over the entire length of the first direction of the stacked electrode body at each of a plurality of sites separated in the second direction.

[0008] According to the above structure, the electrolyte can be allowed to infiltrate into the inside of the stacked electrode body from the unfused site of the second side surface. Thus, compared to the case where the entire second side surface is fused, the electrolyte is more easily allowed to infiltrate into the inside of the stacked electrode body.

[0009] According to another aspect of the present disclosure, an electricity storage module has a stacked electrode body and a housing that houses the stacked electrode body. An electrolyte injection hole through which electrolyte is injected into the housing is formed in the housing. The electrolyte injection hole is formed at an end portion of the housing on the second direction side and is closer to the first side surface than to the second side surface. The separators are fused only at the first side surface and the second side surface.

[0010] According to the above structure, the electrolyte is more easily allowed to pass through the first side surface side than the second side surface. The fused portion hinders the electrolyte from flowing into the stacked electrode body, but since the fused portion exists only on the second side surface side, the electrolyte is more easily allowed to infiltrate into the stacked electrode body than in the case where the electrolyte injection hole is formed on the first side surface side. Therefore, according to the electricity storage module, compared to the case where the electrolyte injection hole is formed closer to the second side surface than to the first side surface, it is possible to allow the electrolyte to efficiently infiltrate into the inside of the stacked electrode body when the electrolyte is injected into the housing.

[0011] Preferably, the separators are fused to each other over the entire length of the first direction of the stacked electrode body at each of a plurality of sites separated in the second direction. The length of the second direction of the plurality of sites is shorter at a site farther from the electrolyte injection hole.

[0012] When the electrolyte is injected into the housing, the electrolyte does not immediately infiltrate into the stacked electrode body but temporarily moves to the side opposite the electrolyte injection hole while passing around the stacked electrode body. Thereafter, the electrolyte moves from the side opposite the electrolyte injection hole to the electrolyte injection hole side within the stacked electrode body 100 due to capillary phenomenon. Due to such an effect, it is possible to supply the electrolyte to the entire region within the stacked electrode body. In addition, as the amount of electrolyte injection increases over time, it is possible to supply the electrolyte from the periphery to the inside of the stacked electrode body. As described above, the length of the second direction is shorter at a site farther from the electrolyte injection hole, so it is possible to allow the electrolyte to efficiently infiltrate into the inside of the stacked electrode body 100C from the portion of the second side surface of the stacked electrode body farther from the electrolyte injection hole.

[0013] The above and other objects, features, aspects and advantages of the present application will become more apparent from the following detailed description of the present application taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a perspective view of the power storage module.

[0015] Figure 2 is a view showing Figure 1 a laminated electrode body included in the power storage module of

[0016] Figure 3 is a III-III line cross-sectional view of Figure 1

[0017] Figure 4 is a view of the laminated electrode body of Figure 3 when viewed in a predetermined orientation.

[0018] Figure 5 is a view showing a first modification of the laminated electrode body.

[0019] Figure 6 is a view showing a second modification of the laminated electrode body.

[0020] Figure 7 is a view showing a third modification of the laminated electrode body.

[0021] Figure 8 is a view showing a fourth modification of the laminated electrode body.

[0022] Figure 9 is a view showing a fifth modification of the laminated electrode body.

[0023] Figure 10 is a view showing a sixth modification of the laminated electrode body.

[0024] Figure 11 is a view showing a cross section of another power storage module. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the drawings. Furthermore, in the embodiments shown below, the same or common parts are attached with the same symbols in the drawings, and the explanation thereof will not be repeated.

[0026] [Embodiment 1]

[0027] Figure 1 is a perspective view of the power storage module of the present embodiment. Figure 2 is a view showing Figure 1 a laminated electrode body included in the power storage module of Figure 1 and Figure 2 , the power storage module 1 is in the shape of a blade. The power storage module 1 is provided with a laminated electrode body 100 and a housing body 2 that houses the laminated electrode body 100. Furthermore, hereinafter, for the sake of convenience, except at the time of injection of the electrolyte solution described later, the power storage module 1 is assumed to be in the state shown in Figure 1 ,​2 The power storage module 1 will be described by taking as an example a case where the posture is such that the direction D3 shown is the vertical direction (more specifically, the direction D31 described later is the vertically upward direction).

[0028] In this example, the storage module 1 is a lithium iron phosphate (LFP) type battery. However, the present invention is not limited thereto, and the storage module 1 may also be a ternary (NMC) type battery. The storage module 1 is, for example, mounted on an electric vehicle that uses a driving force obtained by electric energy to travel. Specifically, a battery pack including a plurality of storage modules 1 arranged in a predetermined direction is mounted on the electric vehicle. The battery pack is mounted on the body of the electric vehicle. The battery pack constitutes a part of the body. The battery pack serves as a structural member of the body.

[0029] like Figure 1 As shown, the container 2 is generally rectangular. In this example, the container 2 is a metal frame. The container 2 has first to sixth surfaces 21 to 26. The first surface 21, the second surface 22, the third surface 23, and the fourth surface 24 are continuous in this order. The first surface 21, the second surface 22, the third surface 23, and the fourth surface 24 constitute the outer peripheral surface of the container 2.

[0030] The fifth and sixth surfaces 25 and 26 are end surfaces of the container 2. The first surface 21 is the top surface, the second surface 22 is the bottom surface, and the third and fourth surfaces 23 and 24 are side surfaces. A negative-side external connection terminal 27 is provided on the fifth surface 25. A positive-side external connection terminal (not shown) is provided on the sixth surface 26.

[0031] like Figure 2 As shown, the stacked electrode body 100 has a plurality of electrodes (negative electrodes 110, positive electrodes 120) and a plurality of separators 130. The plurality of electrodes of the stacked electrode body 100 are stacked in the D1 direction (stacking direction). In detail, in the stacked electrode body 100, the negative electrodes 110 and the positive electrodes 120 are alternately stacked in the D1 direction via the separators 130. That is, in the stacked electrode body 100, the negative electrodes 110, the separators 130, the positive electrodes 120 and the separators 130 are repeatedly arranged in this order. In addition, the D1 direction is the width direction of the battery module 1. The positive electrodes 120 are the same size. The negative electrodes 110 are the same size. The separators 130 are the same size.

[0032] The length of each separator 130 in the direction D3 is longer than the length of each positive electrode 120 in the direction D3. Similarly, the length of each separator 130 in the direction D3 is longer than the length of each negative electrode 110 in the direction D3.

[0033] The laminated electrode body 100 also has a tab 150 connected to the negative-side external connection terminal 27 and a tab 160 connected to the positive-side external connection terminal. The tab 150 is made by collecting copper foils. The tab 160 is made by collecting aluminum foils.

[0034] As shown in FIG. 1, the power storage module 1 and the housing 2 extend in a D2 direction. As shown in FIG. 2, the laminated electrode body 100 extends in the D2 direction. The D2 direction is perpendicular to the D1 direction. The D2 direction is a longitudinal direction of the power storage module 1, the housing 2, and the laminated electrode body 100. The D3 direction is perpendicular to the D1 direction and the D2 direction. The D3 direction is a height direction of the power storage module 1. Figure 1 Figure 2 As shown in FIG. 1, the power storage module 1 and the housing 2 extend in a D2 direction. As shown in FIG. 2, the laminated electrode body 100 extends in the D2 direction. The D2 direction is perpendicular to the D1 direction. The D2 direction is a longitudinal direction of the power storage module 1, the housing 2, and the laminated electrode body 100. The D3 direction is perpendicular to the D1 direction and the D2 direction. The D3 direction is a height direction of the power storage module 1.

[0035] The D1 direction is a short side direction in each of the first face 21, the second face 22, the fifth face 25, and the sixth face 26. The D2 direction is a long side direction in the first face to the fourth face 21 to 24. The D3 direction is a short side direction in the third face and the fourth face 23, 24, and is a long side direction in the fifth face and the sixth face 25, 26.

[0036] The injection hole 2h is formed on the fifth face 25 for injecting an electrolyte into the inside of the housing 2. The injection hole 2h is formed on the first face 21 side than the second face 22 of the housing 2. The injection hole 2h is formed on the first face 21 side than the external connection terminal 27. Further, in a state shown in FIG. 2, the electrolyte has been injected into the inside of the housing 2, so the injection hole 2h is in a plugged state. The injection hole 2h can be temporarily plugged by inserting a removable plug into the injection hole 2h. Alternatively, the injection hole 2h can be plugged with resin or metal so that the electrolyte cannot be injected again as long as the through hole is not opened. Figure 1

[0037] Figure 3 is a cross-sectional view taken along the III-III line of FIG. 3. Figure 1 is a cross-sectional view taken along the III-III line of FIG. 3. Figure 3 is a view showing a cross section of the power storage module 1. As shown in FIG. 4, the power storage module 1 has the housing 2 and the laminated electrode body 100. Figure 3

[0038] The plate-shaped members 201, 202, the tape materials 301, 302, and the insulating sheet 500 are housed in the housing 2 like the laminated electrode body 100. The plate-shaped members 201, 202, the tape materials 301, 302, and the insulating sheet 500 are disposed between the laminated electrode body 100 and the housing 2 (gap).

[0039] ​​​The plate-shaped members 201, 202 extend in the D2 direction. The plate-shaped members 201, 202 are arranged in the housing 2 in such a manner that the D3 direction becomes the direction of the thickness of the plate-shaped member 201. In this example, the plate-shaped member 202 has a shape symmetrical to the plate-shaped member 201 with respect to the laminated electrode body 100. However, the present application is not limited thereto.

[0040] The plate-shaped members 201, 202 are formed with a plurality of through-holes extending in the D3 direction. In the plate-shaped members 201, 202, the plurality of through-holes are arranged in the D2 direction. In addition, the power storage module 1 can not necessarily have the plate-shaped members 201, 202.

[0041] The plate-shaped members 201, 202 are insulators. In this example, the plate-shaped members 201, 202 are formed of resin. From the viewpoint of preventing short-circuiting between the positive electrode 120 and the negative electrode 110 in the laminated electrode body 100, in this example, the plate-shaped members 201, 202 are formed of a material having insulating properties. In addition, in the case where the insulating distance between the plate-shaped members 201, 202 and the laminated electrode body 100 is sufficiently ensured, it is not necessarily required that the plate-shaped members 201, 202 be insulators.

[0042] As a raw material constituting the plate-shaped members 201, 202, for example, polypropylene is used. The present application is not limited thereto, and polyethylene, polyphenylene sulfide, polyether ether ketone, or PET (polyethylene terephthalate), or the like can also be used.

[0043] The plate-shaped member 201 is arranged above the laminated electrode body 100. To be more specific, the plate-shaped member 201 is arranged directly above the laminated electrode body 100. The plate-shaped member 201 is disposed on the side of the first face 21 of the housing 2. The plate-shaped member 201 is disposed in the D31 direction with respect to the laminated electrode body 100. In addition, as described above, the D31 direction is the upward direction.

[0044] The plate-shaped member 202 is arranged below the laminated electrode body 100. To be more specific, the plate-shaped member 202 is arranged directly below the laminated electrode body 100. The plate-shaped member 202 is disposed on the side of the second face 22 of the housing 2. The plate-shaped member 202 is disposed in the D32 direction with respect to the laminated electrode body 100. In addition, the D32 direction is the downward direction.

[0045] The plate-shaped member 201 is fixed to the laminated electrode body 100 by the tape material 301. The plate-shaped member 202 is fixed to the laminated electrode body 100 by the tape material 302. The tape materials 301, 302 extend in the D2 direction. The tape materials 301, 302 cover a part of the laminated electrode body 100.

[0046] The laminated electrode body 100 has a circumferential surface 180. The circumferential surface 180 extends in the D2 direction. In the laminated electrode body 100, the circumferential surface 180 is formed on the side of the positive electrode 120.Figure 3 The cross section of the peripheral surface 180 is shown. The cross section of the peripheral surface 180 is rectangular. The peripheral surface 180 faces the housing 2. The peripheral surface 180 faces the inner peripheral surface of the housing 2. The peripheral surface 180 faces the housing 2 through the member such as the insulating sheet 500.

[0047] The peripheral surface 180 has the first and second side surfaces 181, 182 on the D3 direction side and the first and second main surfaces 183, 184 on the D1 direction side. That is, the peripheral surface 180 has the first and second side surfaces 181, 182 whose normal directions are the D3 direction and the first and second main surfaces 183, 184 whose normal directions are the D1 direction.

[0048] The first side surface 181 is continuous with the first and second main surfaces 183, 184. The first side surface 181 is a top surface. Likewise, the second side surface 182 is also continuous with the first and second main surfaces 183, 184. The second side surface 182 is a bottom surface.

[0049] The first side surface 181 is parallel to the first surface 21 of the housing 2. The second side surface 182 is parallel to the second surface 22. The first side surface 181 is a surface closer to the first surface 21 of the housing 2 than the second side surface 182. The first main surface 183 is parallel to the third surface 23. The second main surface 184 is parallel to the fourth surface 24. The first main surface 183 is a surface closer to the third surface 23 than the second main surface 184. The width of the first and second side surfaces 181, 182 in the D1 direction is narrower than the width of the first and second main surfaces 183, 184 in the D3 direction.

[0050] The insulating sheet 500 is provided between the peripheral surface 180 of the laminated electrode body 100 and the housing 2 and covers the peripheral surface 180. The insulating sheet 500 insulates the laminated electrode body 100 from the housing 2. The insulating sheet 500 covers the laminated electrode body 100 in such a manner that the laminated electrode body 100 does not contact the housing 2. The insulating sheet 500 is provided between the laminated electrode body 100 and the housing 2 (in detail, the inner surface of the housing) in order to prevent short circuit of the laminated electrode body 100.

[0051] In detail, the insulating sheet 500 covers the plate-like members 201, 202. The insulating sheet 500 covers the plate-like member 201 through the tape material 301. Likewise, the insulating sheet 500 covers the plate-like member 202 through the tape material 302.

[0052] Both end portions of the insulating sheet 500 are fused to each other. In a state where the plate-like members 201, 202 are fixed to the laminated electrode body 100 by the tape materials 301, 302, the insulating sheet 500 is wound around the tape materials 301, 302, the plate-like members 201, 202, and the laminated electrode body 100. Thereafter, both end portions of the insulating sheet 500 are fused to each other, whereby the insulating sheet 500 is obtained. Figure 3The insulating sheet 500 shown in FIG. The ends of the insulating sheet 500 overlap each other in the welded region T. The welded region T extends in the direction D2. Alternatively, the insulating sheet 500 may be formed by connecting a plurality of insulating sheets.

[0053] In addition, as a material constituting the insulating sheet 500, polypropylene is used, for example, but the present invention is not limited thereto, and polyethylene, polyphenylene sulfide, polyetheretherketone, nylon, or PET (polyethylene terephthalate) may also be used.

[0054] Figure 4 Observe in the direction of arrow B Figure 3 FIG. 1 is a diagram showing the case of a stacked electrode body 100. Figure 4 As shown, the stacked electrode body 100 has a first end face 185 and a second end face 186 in addition to a first side face 181 , a second side face 182 , a first main face 183 , and a second main face 184 .

[0055] The first end surface 185 is provided with the negative-side external connection terminal 27 ( Figure 1 ) is a surface on the side of the fifth surface 25. The second end surface 186 is provided with the sixth surface 26 ( Figure 1 ) side.

[0056] On the second side surface 182, each separator 130 is welded over the entire length of the stacked electrode body 100 in the D1 direction. This structure restricts the movement of each separator 130 in the D3 direction within the stacked electrode body 100. Therefore, the stacked electrode body 100 can prevent the position of each separator 130 from shifting. Furthermore, the stacked electrode body 100 can suppress the amount of protrusion of each separator 130 from the outer edges of the negative electrode 110 and the positive electrode 120. Therefore, the stacked electrode body 100 can suppress the amount of space that does not contribute to charging and discharging.

[0057] Specifically, each of the multiple locations separated in the D2 direction on each separator 130 is welded together along the entire length of the stacked electrode body 100 in the D1 direction. In this embodiment, the separators 130 are directly welded to each other. In the stacked electrode body 100, there are multiple welded portions U1 formed by welding the separators 130 together.

[0058] The length of each welded portion U1 in the D1 direction is the same. This length in the D1 direction is approximately the same as the length of the stacked electrode body 100 in the D1 direction. The length of each welded portion U1 in the D2 direction is the same. In this example, each welded portion U1 is formed evenly in the D2 direction. Adjacent welded portions U1 are separated by the same distance. Each welded portion U1 is typically formed by contacting each separator 130 with a hot soldering iron.

[0059] Each welded portion U1 covers a portion of the positive electrode 120 and a portion of the negative electrode 110 in the direction D1 when the stacked electrode assembly 100 is viewed from the second side surface 182. Each welded portion U1 may contact the outer edge of the positive electrode 120 and the outer edge of the negative electrode 110.

[0060] The multiple separators 130 are fixed to each other by the welded portions U1. The relative positions of the separators 130 are fixed on the second side surface 182. Consequently, movement of the separators 130 in the direction D3 within the stacked electrode assembly 100 is restricted. Thus, the battery module 1 can prevent positional deviation of the separators 130. Furthermore, the welded portions can be made smaller than when the separators 130 are welded to each other across the entire surface of the second side surface 182.

[0061] As described above, by directly welding the separators 130 to each other, the position of each separator 130 can be fixed without using any other components. Furthermore, in the battery module 1, since the welded portions U1 are formed evenly in the direction D2 as described above, the effect of preventing positional deviation of the separators 130 is greater than when the welded portions U1 are not formed evenly.

[0062] The positive electrodes 120 and the negative electrodes 110 are sandwiched between the separators 130. Therefore, movement of the positive electrodes 120 and the negative electrodes 110 in the direction D3 relative to the separators 130 can be restricted. Specifically, positional deviation of the positive electrodes 120 and the negative electrodes 110 in the direction D31 relative to the separators 130 can also be suppressed.

[0063] Furthermore, the storage module 1 injects the electrolyte from the injection hole 2h ( Figure 1 ) into the container 2, the following advantages are achieved. When the electrolyte is injected from the injection port 2h during manufacture of the battery module 1, the battery module 1 is positioned so that the direction D2 is approximately vertical and the fifth surface 25 is positioned above the sixth surface 26. Due to its own weight, the electrolyte flows from the fifth surface 25 to the sixth surface 26. Furthermore, the electrolyte has a certain degree of viscosity, so it falls relatively slowly within the container 2. This allows the electrolyte to permeate the stacked electrode assembly 100.

[0064] In this regard, as described above, on the second side surface 182 of the stacked electrode body 100, the separators 130 are not welded to each other between the welded portions U1. Therefore, when the electrolyte drops within the container 2 or when the dropped electrolyte rises, the electrolyte can penetrate into the interior of the stacked electrode body 100 from the unwelded portions of the second side surface 182 (hereinafter also referred to as "non-welded portions"). Furthermore, since there are no welded portions U1 on the first side surface 181, the electrolyte can penetrate into the interior of the stacked electrode body 100 from the entire first side surface 181 when the electrolyte drops within the container 2.

[0065] Thus, the separators 130 are fused to each other at each of the plurality of portions of the second side surface 182 over the entire length in the D1 direction of the stacked electrode body 100, so that the electrolyte solution is more easily impregnated in the interior of the stacked electrode body 100 as compared with the case where the entire second side surface 182 is fused.

[0066] However, as described above, the injection hole 2h is formed on the first side surface 21 side of the housing 2 than on the second side surface 22. The injection hole 2h is located on the first side surface 181 side of the stacked electrode body 100 than on the second side surface 182 in the D3 direction. That is, the first side surface 181 where the fusion portion U1 is not formed is present closer to the injection hole 2h than the second side surface 22 where the fusion portion U1 is formed.

[0067] When the electrolyte solution flows in the D2 direction by gravity via the injection hole 2h, the injection hole 2h is closer to the first side surface 181 than the second side surface 182, so that the electrolyte solution is more easily passed on the first side surface 181 side than on the second side surface 182. The fusion portion U1 hinders the electrolyte solution from flowing into the stacked electrode body 100, but the fusion portion U1 is present only on the second side surface 182 side, so that the electrolyte solution is more easily impregnated in the stacked electrode body 100 than in the case where the first side surface 181 is present.

[0068] Thus, according to such a structure, the electrolyte solution is more efficiently impregnated in the interior of the stacked electrode body 100 when the electrolyte solution is injected into the housing 2 than in the case where the injection hole 2h is formed on the second side surface 182 side of the first side surface 181.

[0069] Further, the fusion portion U1 can also be formed on the first side surface 181 Figure 3 ), as with the second side surface 182. In this case, the position deviation of the separators 130 can be further prevented than in the case where the separators 130 are fused on the second side surface 182. Furthermore, according to such a structure, the position deviation of the orientations of the positive electrodes 120 and the negative electrodes 110 in the D32 direction with respect to the separators 130 can also be suppressed. Thus, according to this structure, the position deviation of the orientations of the positive electrodes 120 and the negative electrodes 110 in the D3 direction with respect to the separators 130 can be suppressed.

[0070] Not limited to the above, the fusion portion U1 can be formed only on the first side surface 181 of the first and second side surfaces 181 and 182. It is only necessary that the separators 130 be fused over the entire length in the D1 direction of the stacked electrode body 100 on at least one of the first and second side surfaces 181 and 182.

[0071] In the present example, the liquid injection hole 2h is formed on the first face 21 side than the external connection terminal 27, but is not limited thereto. The liquid injection hole 2h can also be formed on the second face 22 side than the external connection terminal 27. The liquid injection hole 2h can also be formed on the third face 23 side than the external connection terminal 27. The liquid injection hole 2h can also be formed on the fourth face 24 side than the external connection terminal 27.

[0072] Further, in the present example, an example in which the liquid injection hole 2h is formed on the fifth face 25 is described, but is not limited thereto. For example, the liquid injection hole 2h can also be formed on the sixth face 26. The liquid injection hole 2h can also be formed on the first face 21 or the second face 22. In the case where the liquid injection hole 2h is formed on the first face 21 or the second face 22, the liquid injection hole 2h is preferably formed on the end portion side (fifth face 25 side or sixth face 26 side) than the central portion in the longitudinal direction of the housing 2 from the viewpoint of the liquid injection property. The liquid injection hole 2h can also be formed on the third face 23 or the fourth face 24. The formation position of the liquid injection hole 2h is not particularly limited.

[0073] <Summary>

[0074] As described above, the power storage module 1 is provided with: the stacked electrode body 100 in which the electrolytic solution is impregnated; and the housing 2 that houses the stacked electrode body 100. As shown in Figure 2 In the stacked electrode body 100, the positive electrode 120, the separator 130, and the negative electrode 110 are alternately stacked in the D1 direction and extend in the D2 direction that is perpendicular to the D1 direction.

[0075] As shown in Figure 3 The stacked electrode body 100 has a peripheral face 180 that extends in the D2 direction and opposes the housing 2 (in detail, the inner peripheral face of the housing). The length of each separator 130 in the D3 direction that is perpendicular to the D1 direction and the D2 direction is longer than the length of each positive electrode 120 and each negative electrode 110 in the D3 direction. As shown in Figure 3 The peripheral face 180 has a first and a second main face 183, 184 on the D1 direction side and a first and a second side face 181, 182 on the D3 direction side that respectively continue to the first and the second main face 183, 184.

[0076] As shown in Figure 3 The width of the first and the second side face 181, 182 in the D1 direction is narrower than the width of the first and the second main face 183, 184 in the D3 direction. In Figure 4 In the example shown in

[0077] In detail, as shown in Figure 4As shown, each of the separators 130 is fused to each other at each of the plurality of portions separated in the D2 direction over the entire length of the D1 direction of the laminated electrode body 100.

[0078] More specifically, as shown in Figure 1 As shown, the accommodation body 2 is formed with a liquid injection hole 2h for injecting electrolyte into the power storage module 1. As shown in Figure 1 As shown, the liquid injection hole 2h is formed at the end portion of the accommodation body 2 on the D2 direction side and is closer to the first side surface 181 than to the second side surface 182. As shown in Figure 4 As shown, the separators 130 are fused only at the second side surface 182 among the first side surface 181 and the second side surface 182. Further, not limited thereto, the separators 130 can be fused over the entire length of the D1 direction of the laminated electrode body 100 at least one of the first side surface 181 and the second side surface 182.

[0079] <Modification Example>

[0080] Hereinafter, a modification example of the laminated electrode body 100 will be described. More specifically, a modification example of the fusion position of the separators 130 will be described.

[0081] (1) First Modification Example

[0082] Figure 5 is a view showing a first modification example of the laminated electrode body 100. As shown in Figure 5 In the laminated electrode body 100A, as with the laminated electrode body 100, the separators 130 are fused to each other over the entire length of the D1 direction of the laminated electrode body 100A at the second side surface 182. More specifically, each of the separators 130 is fused to each other at each of the plurality of portions separated in the D2 direction over the entire length of the D1 direction of the laminated electrode body 100A. The separators 130 are directly fused to each other. In the laminated electrode body 100A, there are a plurality of fusion portions U1 formed based on the fusion of the separators 130 to each other.

[0083] In the laminated electrode body 100A, the fusion portions U1 exist at the central portion of the second side surface 182 in the D2 direction. In the laminated electrode body 100A, the fusion portions U1 do not exist at the end portions of the second side surface 182 in the D2 direction.

[0084] According to the laminated electrode body 100A of such a structure, the same effects as the laminated electrode body 100 can be obtained. Further, according to the laminated electrode body 100A, it is easier to cause electrolyte to infiltrate into the laminated electrode body than the laminated electrode body 100. In particular, according to the laminated electrode body 100A, it is easier to cause electrolyte to infiltrate from both end portions in the D2 direction of the second side surface 182 than the laminated electrode body 100.

[0085] (2) Second Modification Example

[0086] Figure 6 is a view showing a second modification example of the laminated electrode body 100. As shown in the drawing, in the laminated electrode body 100B, like the laminated electrode body 100, each separator 130 is fused in the entire length of the D1 direction of the laminated electrode body 100B at the second side surface 182. Specifically, each separator 130 is fused to each other in the entire length of the D1 direction of the laminated electrode body 100B at each of a plurality of sites where the separators 130 are separated in the D2 direction. The separators 130 are directly fused to each other. In the laminated electrode body 100B, there are a plurality of fusion portions U1 formed based on the fusion of each separator 130 to each other. Figure 6

[0087] In the laminated electrode body 100B, the fusion portions U1 exist in the D2 direction from the end portion of the second side surface 182. In the laminated electrode body 100B, there is no fusion portion U1 in the central portion in the D2 direction.

[0088] According to the laminated electrode body 100B of such a structure, the same effects as the laminated electrode body 100 can be obtained. Further, according to the laminated electrode body 100B, compared with the laminated electrode body 100, it is easier for the electrolytic solution to penetrate into the laminated electrode body. In particular, according to the laminated electrode body 100B, compared with the laminated electrode body 100, it is easier for the electrolytic solution to penetrate from the central portion in the D2 direction of the second side surface 182.

[0089] (3) Third Modification Example

[0090] Figure 7 is a view showing a third modification example of the laminated electrode body 100. As shown in the drawing, in the laminated electrode body 100C, like the laminated electrode body 100, each separator 130 is fused in the entire length of the D1 direction of the laminated electrode body 100C at the second side surface 182. Specifically, each separator 130 is fused to each other in the entire length of the D1 direction of the laminated electrode body 100C at each of a plurality of sites where the separators 130 are separated in the D2 direction. The separators 130 are directly fused to each other. Figure 7

[0091] In the laminated electrode body 100C, there are a plurality of fusion portions U2, U3, U4, U5 formed based on the fusion of each separator 130 to each other. From the second end surface 186 side to the first end surface 185, the fusion portion U2, the fusion portion U3, the fusion portion U4, and the fusion portion U5 exist in this order.

[0092] ​​The length in the D1 direction of the welds U2, U3, U4, U5 is the same as the length in the D1 direction of the weld U1. The length (width) in the D2 direction of the welds U2, U3, U4, U5 is shorter in this order. With respect to the welds U2, U3, U4, U5, the farther the weld is from the fifth face 25 (the face on the first end face 185 side) of the housing 2, the shorter the length (width) in the D2 direction. That is, with respect to the welds U2, U3, U4, U5, the farther the weld is from the liquid injection hole 2h, the shorter the length (width) in the D2 direction.

[0093] However, when the electrolyte is injected into the housing 2, the electrolyte does not immediately permeate the laminated electrode body 100C, but temporarily moves (falls) from the first end face 185 side to the side opposite the liquid injection hole 2h (the second end face 186 side) through the periphery of the laminated electrode body 100C. Thereafter, the electrolyte moves (rises) from the side opposite the liquid injection hole 2h (the second end face 186 side) to the first end face 185 side (the liquid injection hole 2h side) in the laminated electrode body 100C due to capillary action. Due to this action, the electrolyte can be supplied throughout the entire region in the laminated electrode body 100C.

[0094] In addition, as the amount of electrolyte injected increases over time, the electrolyte can be supplied from the periphery to the laminated electrode body 100C in the laminated electrode body 100C. At this time, the farther the weld is from the liquid injection hole 2h, the shorter the length (width) in the D2 direction, so the electrolyte can be efficiently permeated to the inside of the laminated electrode body 100C from the portion of the second side face 182 of the laminated electrode body 100C that is farther from the liquid injection hole 2h (in detail, the non-welded portion).

[0095] (4) Fourth Modified Example

[0096] Figure 8 is a view showing a fourth modified example of the laminated electrode body 100. As shown in Figure 8 In the laminated electrode body 100D, as with the laminated electrode body 100, the separators 130 are welded on the second side face 182 over the entire length in the D1 direction of the laminated electrode body 100D. Specifically, the separators 130 are welded to each other at each of the multiple portions separated in the D2 direction over the entire length in the D1 direction of the laminated electrode body 100D. The separators 130 are directly welded to each other.

[0097] In the stacked electrode body 100D, as with the stacked electrode body 100C, there are a plurality of fused portions U2, U3, U4, U5 formed based on the fusion of each separator 130 to each other. In the stacked electrode body 100D, unlike the stacked electrode body 100C, from the 2nd end surface 186 side toward the 1st end surface 185, the fused portion U5, the fused portion U4, the fused portion U3, and the fused portion U2 exist in this order.

[0098] In the stacked electrode body 100D, with respect to the fused portions U2, U3, U4, U5, the closer the fused portion is to the 5th surface 25 (the surface of the 1st end surface 185 side) of the housing 2, the shorter the length (width) in the D2 direction. That is, with respect to the fused portions U2, U3, U4, U5, the closer the fused portion is to the liquid injection hole 2h, the shorter the length (width) in the D2 direction.

[0099] According to the stacked electrode body 100D of such a structure, the same effects as the stacked electrode body 100 can be obtained. In addition to this, when the electrolytic solution is injected into the housing 2, the electrolytic solution that moves (falls) from the 1st end surface 185 side to the side opposite the liquid injection hole 2h can be efficiently infiltrated into the stacked electrode body 100D.

[0100] (5) 5th Modification Example

[0101] Figure 9 is a view that shows a 5th modification example of the stacked electrode body 100. As shown in Figure 9 In the stacked electrode body 100E, as with the stacked electrode body 100, in the 2nd side surface 182, each separator 130 is fused over the entire length of the D1 direction of the stacked electrode body 100E. Specifically, each separator 130 is fused to each other over the entire length that is shorter than the length (thickness) of the D1 direction of the stacked electrode body 100E at each of a plurality of portions where each separator 130 is separated in the D2 direction. The separators 130 are directly fused to each other.

[0102] In the stacked electrode body 100E, a plurality of fused portions U6 and a plurality of fused portions U7 exist due to the fusion of each separator 130 to each other. In the stacked electrode body 100E, in the D2 direction, the fused portions U6 and the fused portions U7 are alternately formed. The fused portions U6 and the fused portions U7, for example, partially coincide in the D1 direction when the stacked electrode body 100E is observed toward the D21 direction. By this coincidence, the positions of all of the separators 130 to each other are fixed.

[0103] In detail, the respective fusion portions U6 are formed at equal intervals in the D2 direction. The respective fusion portions U6 are formed from the second main surface 184 toward the first main surface 183 in the D1 direction. The respective fusion portions U6 do not reach the first main surface 183. The respective fusion portions U6 extend from the second main surface 184 to a position between the position of the first main surface 183 and the middle position of the second side surface 182 in the D1 direction.

[0104] Likewise, the respective fusion portions U7 are formed at equal intervals in the D2 direction. The respective fusion portions U7 are formed from the first main surface 183 toward the second main surface 184 in the D1 direction. The respective fusion portions U7 do not reach the second main surface 184. The respective fusion portions U7 extend from the first main surface 183 to a position between the position of the second main surface 184 and the middle position of the second side surface 182 in the D1 direction.

[0105] According to the laminated electrode body 100E of such a structure, the same effects as the laminated electrode body 100 can be obtained.

[0106] (6) Sixth Modification

[0107] Figure 10 is a view that shows a sixth modification of the laminated electrode body 100. As Figure 10 indicated, in the laminated electrode body 100F, as with the laminated electrode body 100, the respective separators 130 are fused in the D1 direction of the laminated electrode body 100F over the entire length of the second side surface 182. The separators 130 are directly fused to each other.

[0108] In the laminated electrode body 100F, one fusion portion U8 is formed. The fusion portion U8 has an X shape when the second side surface 182 is viewed in the direction of D31. The separators 130 are fused to each other in two regions separated in the D1 direction at both end portions of the second side surface 182 in the D2 direction. The separators 130 are fused to each other in only one region in the D1 direction at the central portion of the second side surface 182 in the D2 direction.

[0109] According to the laminated electrode body 100C of such a structure, the same effects as the laminated electrode body 100 can be obtained. Furthermore, it is easy to fuse all of the separators 130 by one fusion process.

[0110] [Embodiment 2]

[0111] In the present embodiment, points different from the power storage module 1 of Embodiment 1 are described.

[0112] Figure 11 is a view that shows a cross section of the power storage module 1A of the present embodiment. As Figure 11As shown, the electricity storage module 1A has the housing 2, the stacked electrode body 100, the plate-shaped members 201, 202, the band materials 301, 302, the insulating sheet 500, and the plate-shaped member 400.

[0113] The electricity storage module 1A is different from the electricity storage module 1 of Embodiment 1 in that the plate-shaped member 400 is provided. The plate-shaped member 400 is positioned between the stacked electrode body 100 and the plate-shaped member 202. With regard to the plate-shaped member 400, the plate-shaped member 400 extends not only in the D1 direction but also in the D2 direction. The plate-shaped member 400 is typically a resin material.

[0114] In the electricity storage module 1A, as with the electricity storage module 1, each separator 130 is welded at the 2nd side surface 182 over the entire length of the stacked electrode body 100 in the D1 direction. In detail, in the electricity storage module 1A, each separator 130 of the stacked electrode body 100 is welded to the plate-shaped member 400. In this way, in the electricity storage module 1A, each separator 130 is welded to each other via the plate-shaped member 400.

[0115] The plate-shaped member 400 preferably includes a plurality of element members arranged at intervals in the D2 direction. Each element member is provided, for example, at a position corresponding to the welding portion U1 of Figure 4 , and each separator 130 is thermally welded to the element member. The arrangement of each element member is not limited to this, and each element member can be provided at a position corresponding to each welding portion in Figures 5-11 .

[0116] The electricity storage module 1A according to such a structure can achieve the same effects as those achieved by the electricity storage module 1 of Embodiment 1. Furthermore, in the electricity storage module 1A, the plate-shaped member 400 is used, so it is easier to fix the positions of the separators 130 than in the structure in which the separators 130 are directly welded to each other as in Embodiment 1.

[0117] The electricity storage module 1A, like the electricity storage module 1 of Embodiment 1, includes the stacked electrode body 100. Thus, as explained in Embodiment 1, in this embodiment, it is possible to prevent the positions of the separators 130 from deviating, and it is possible to suppress the space that does not contribute to charge and discharge.

[0118] Furthermore, the plate-shaped member 400 can be positioned between the stacked electrode body 100 and the plate-shaped member 201. The plate-shaped member 400 can be provided between the stacked electrode body 100 and the plate-shaped member 202 and between the stacked electrode body 100 and the plate-shaped member 201, respectively.

[0119] Embodiments of the application are illustrated by way of example in the accompanying drawings in which:

Claims

1. A stacked electrode body, comprising: a plurality of electrodes; and a plurality of separators, each of the electrodes and each of the separators being alternately stacked in a first direction, the stacked electrode body extending in a second direction perpendicular to the first direction, further comprising a peripheral surface extending in the second direction, a length of each of the separators in a third direction perpendicular to the first direction and the second direction being longer than a length of each of the electrodes in the third direction, the peripheral surface having a first main surface on the first direction side and a second main surface, and a first side surface and a second side surface on the third direction side which are continuous to the first main surface and the second main surface, respectively, and each of the separators being welded in at least one of the first side surface and the second side surface over an entire length of the stacked electrode body in the first direction.

2. The stacked electrode body according to claim 1, wherein each of the separators is welded to each other at each of a plurality of sites separated in the second direction over the entire length of the stacked electrode body in the first direction.

3. An electricity storage module, comprising: the stacked electrode body according to claim 1; and a housing body housing the stacked electrode body, a liquid injection hole through which an electrolyte is injected into the housing body being formed in the housing body, the liquid injection hole being formed at an end portion of the housing body on the second direction side and being closer to the first side surface than to the second side surface, and each of the separators being welded only in the second side surface of the first side surface and the second side surface.

4. The electricity storage module according to claim 3, wherein each of the separators is welded to each other at each of a plurality of sites separated in the second direction over the entire length of the stacked electrode body in the first direction, and a length of the second direction of each of the plurality of sites is shorter as a site is farther from the liquid injection hole. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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