JP7056472B2 - Power storage module - Google Patents

Description

The present disclosure relates to a power storage module.

As a conventional power storage module, a bipolar battery including a bipolar electrode having a positive electrode formed on one surface of an electrode plate and a negative electrode formed on the other surface is known (see Patent Document 1). The bipolar battery includes a laminate formed by laminating a plurality of bipolar electrodes via a separator. On the side surface of the laminated body, a sealing body for sealing between the bipolar electrodes adjacent to each other in the stacking direction is provided, and the electrolytic solution is housed in the internal space formed between the bipolar electrodes.

Japanese Unexamined Patent Publication No. 2011-204386

The sealant that seals between the bipolar electrodes has, for example, a frame-shaped resin portion provided at the edge of the electrode plate of the bipolar electrode. The resin portion is located between the electrode plates of each bipolar electrode in the laminated body of the bipolar electrodes, and has a role of ensuring the withstand voltage strength of the power storage module. If the withstand voltage is insufficient, for example, deformation of the electrode laminate when the internal pressure rises may occur. Therefore, the power storage module is required to secure sufficient withstand voltage.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a power storage module capable of sufficiently ensuring a withstand voltage strength.

The power storage module according to one aspect of the present disclosure includes an electrode laminate in which a plurality of bipolar electrodes are laminated, and a sealed body provided so as to surround the side surface of the electrode laminate and seal between the bipolar electrodes. The sealed body has a plurality of resin portions bonded to the edge portion on one surface side of the electrode plate included in the electrode laminate, and the electrode plate has a roughened surface at least in the bonding region with the resin portion. The protrusion height of the roughened surface of the electrode plate located in the outermost layer in the stacking direction in the electrode laminate is larger than the protrusion height of the roughened surface of the electrode plate on the inner layer side of the outermost layer. There is.

In this power storage module, the roughened surface provided on the electrode plate can increase the bonding strength between the electrode plate and the resin portion. Further, in this power storage module, the protrusion height of the roughened surface of the electrode plate on the outermost layer is larger than the protrusion height of the roughened surface of the electrode plate on the inner layer side. As a result, the bond strength between the electrode plate of the outermost layer to which pressure is easily applied and the resin portion is sufficiently secured, so that the withstand voltage strength can be sufficiently secured.

Further, the protrusion height of the electrode plate on the outermost layer may be twice or more the protrusion height of the electrode plate on the inner layer side. As a result, the bond strength between the electrode plate of the outermost layer and the resin portion is further sufficiently secured, and the withstand voltage strength is further improved.

Further, a negative electrode terminal electrode is provided at one end of the electrode laminate in the stacking direction, and a positive electrode terminal electrode is provided at the other end of the electrode laminate in the stacking direction. The electrode plate of may be the outermost electrode plate. In this case, the bond strength between the electrode plate of the negative electrode terminal electrode and the positive electrode terminal electrode located in the outermost layer of the electrode laminate and the resin portion is sufficiently secured, and the withstand voltage strength can be sufficiently secured.

Further, both sides of the electrode plate of the negative electrode terminal electrode are roughened surfaces, and the other surface of the electrode plate may be bonded to a resin portion bonded to the electrode plates of adjacent bipolar electrodes. In this case, the electrode plate of the negative electrode terminal electrode is also bonded to the resin portion bonded to the electrode plate of the bipolar electrode, so that the withstand voltage strength can be further improved.

Further, a negative electrode terminal electrode and a metal plate located outside the negative electrode terminal electrode are provided at one end of the electrode laminate in the stacking direction, and a positive electrode terminal electrode is provided at the other end of the electrode laminate in the stacking direction. May be provided, and the metal plate and the electrode plate of the positive electrode terminal electrode may be the outermost metal plate. In this case, the metal plate can suppress the deformation of the resin portion bonded to the electrode plate of the negative electrode terminal electrode. Therefore, it is possible to suppress the occurrence of leakage of the electrolytic solution due to the alkaline creep phenomenon or the like. Further, the bond strength between the metal plate located in the outermost layer of the electrode laminate and the electrode plate of the positive electrode terminal electrode and the resin portion is sufficiently secured, and the withstand voltage strength can be sufficiently secured.

Further, both sides of the metal plate are roughened surfaces, and the other surface of the metal plate may be bonded to the resin portion bonded to the electrode plate of the negative electrode terminal electrode. In this case, the metal plate is also bonded to the resin portion bonded to the electrode plate of the negative electrode terminal electrode, so that the pressure resistance is further improved.

Further, both sides of the electrode plate of the negative electrode terminal electrode are roughened surfaces, and the other surface of the electrode plate may be bonded to a resin portion bonded to the electrode plates of adjacent bipolar electrodes. In this case, the electrode plate of the negative electrode terminal electrode is also bonded to the resin portion bonded to the electrode plate of the bipolar electrode, so that the withstand voltage strength can be further improved.

According to the present disclosure, sufficient pressure resistance can be ensured.

It is a schematic sectional drawing which shows the electric power storage apparatus which is configured with the electric power storage module which concerns on this embodiment. FIG. 3 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. 1. It is a schematic diagram which shows the state of a roughened surface. It is a schematic sectional drawing which shows the internal structure of the power storage module which concerns on the modification.

Hereinafter, a preferred embodiment of the power storage module according to one aspect of the present disclosure will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing a power storage device including a power storage module according to the present embodiment. The power storage device 1 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a module stack 2 including a plurality of stacked power storage modules 4, and a restraint member 3 that applies a restraining load to the module stack 2 in the stacking direction of the module stack 2.

The module stack 2 includes a plurality of (here, three) power storage modules 4 and a plurality of (here, four) conductive plates 5. The power storage module 4 is a bipolar battery and has a rectangular shape when viewed from the stacking direction. The power storage module 4 is, for example, a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, or an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery will be illustrated.

The storage modules 4 adjacent to each other in the stacking direction are electrically connected to each other via the conductive plate 5. The conductive plates 5 are arranged between the power storage modules 4 adjacent to each other in the stacking direction and outside the power storage modules 4 located at the stacking ends. A positive electrode terminal 6 is connected to one of the conductive plates 5 arranged outside the power storage module 4 located at the laminated end. The negative electrode terminal 7 is connected to the other conductive plate 5 arranged outside the power storage module 4 located at the laminated end. The positive electrode terminal 6 and the negative electrode terminal 7 are drawn out from the edge of the conductive plate 5, for example, in a direction intersecting with each other in the stacking direction. The positive electrode terminal 6 and the negative electrode terminal 7 charge and discharge the power storage device 1.

Inside the conductive plate 5, a plurality of flow paths 5a through which a refrigerant such as air flows are provided. The flow path 5a extends along a direction intersecting (orthogonal) with, for example, the stacking direction and the drawing direction of the positive electrode terminal 6 and the negative electrode terminal 7. The conductive plate 5 not only functions as a connecting member for electrically connecting the power storage modules 4 to each other, but also serves as a heat sink that dissipates heat generated by the power storage module 4 by circulating a refrigerant through these flow paths 5a. It also has a function. In the example of FIG. 1, the area of the conductive plate 5 seen from the stacking direction is smaller than the area of the power storage module 4, but from the viewpoint of improving heat dissipation, the area of the conductive plate 5 is the power storage module. It may be the same as the area of 4 and may be larger than the area of the power storage module 4.

The restraint member 3 is composed of a pair of end plates 8 that sandwich the module laminate 2 in the stacking direction, and fastening bolts 9 and nuts 10 that fasten the end plates 8 to each other. The end plate 8 is a rectangular metal plate having an area one size larger than the area of the power storage module 4 and the conductive plate 5 when viewed from the stacking direction. A film F having electrical insulation is provided on the surface of the end plate 8 on the module laminate 2 side. The film F insulates between the end plate 8 and the conductive plate 5.

An insertion hole 8a is provided at the edge of the end plate 8 at a position outside the module laminate 2. The fastening bolt 9 is passed from the insertion hole 8a of one end plate 8 toward the insertion hole 8a of the other end plate 8, and is attached to the tip portion of the fastening bolt 9 protruding from the insertion hole 8a of the other end plate 8. , The nut 10 is screwed. As a result, the power storage module 4 and the conductive plate 5 are sandwiched by the end plate 8 to be unitized as the module laminate 2, and a restraining load is applied to the module laminate 2 in the stacking direction.

Next, the configuration of the power storage module 4 will be described in detail. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. FIG. 3 is an enlarged cross-sectional view of a main part of FIG. As shown in FIGS. 2 and 3, the power storage module 4 includes an electrode laminate 11 and a resin sealant 12 that seals the electrode laminate 11. The electrode laminate 11 is composed of a plurality of electrodes laminated along the stacking direction D of the power storage module 4 via the separator 13. These electrodes include a laminate of a plurality of bipolar electrodes 14, a negative electrode termination electrode 18, and a positive electrode termination electrode 19.

The bipolar electrode 14 has an electrode plate 15 including one surface 15a and the other surface 15b on the opposite side of the one surface 15a, a positive electrode 16 provided on the one surface 15a, and a negative electrode 17 provided on the other surface 15b. ing. The positive electrode 16 is a positive electrode active material layer formed by applying a positive electrode active material to the electrode plate 15. The negative electrode 17 is a negative electrode active material layer formed by applying a negative electrode active material to the electrode plate 15. In the electrode laminate 11, the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of another bipolar electrode 14 adjacent to one of the stacking directions D with the separator 13 interposed therebetween. In the electrode laminate 11, the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of another bipolar electrode 14 adjacent to the other in the stacking direction D with the separator 13 interposed therebetween.

The negative electrode terminal electrode 18 has an electrode plate 15 and a negative electrode 17 provided on the other surface 15b of the electrode plate 15. The negative electrode terminal electrode 18 is arranged at one end of the stacking direction D so that the other surface 15b faces the center side of the stacking direction D in the electrode laminated body 11. One surface 15a of the electrode plate 15 of the negative electrode terminal electrode 18 constitutes one outer surface in the stacking direction of the electrode laminate 11, and is electrically connected to one conductive plate 5 (see FIG. 1) adjacent to the power storage module 4. It is connected. The negative electrode 17 provided on the other surface 15b of the electrode plate 15 of the negative electrode terminal electrode 18 faces the positive electrode 16 of the bipolar electrode 14 at one end in the stacking direction D via the separator 13.

The positive electrode terminal electrode 19 has an electrode plate 15 and a positive electrode 16 provided on one surface 15a of the electrode plate 15. The positive electrode terminal electrode 19 is arranged at the other end of the stacking direction D so that one surface 15a faces the center side of the stacking direction D in the electrode laminated body 11. The positive electrode 16 provided on one surface 15a of the positive electrode terminal electrode 19 faces the negative electrode 17 of the bipolar electrode 14 at the other end in the stacking direction D via the separator 13. The other surface 15b of the electrode plate 15 of the positive electrode terminal electrode 19 constitutes the other outer surface of the electrode laminate 11 in the stacking direction, and is electrically connected to the other conductive plate 5 (see FIG. 1) adjacent to the power storage module 4. It is connected.

The electrode plate 15 is made of a metal such as nickel or a nickel-plated steel plate. As an example, the electrode plate 15 is a rectangular metal leaf made of nickel. The edge portion 15c of the electrode plate 15 has a rectangular frame shape, and is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated. Examples of the positive electrode active material constituting the positive electrode 16 include nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode 17 include a hydrogen storage alloy. In the present embodiment, the formation region of the negative electrode 17 on the other surface 15b of the electrode plate 15 is slightly larger than the formation region of the positive electrode 16 on the one surface 15a of the electrode plate 15.

The separator 13 is formed, for example, in the form of a sheet. Examples of the separator 13 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene, methyl cellulose and the like, or a non-woven fabric. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 is not limited to a sheet shape, and a bag shape may be used.

The sealing body 12 is formed in a rectangular frame shape as a whole by, for example, an insulating resin. The sealing body 12 is provided on the side surface 11a of the electrode laminated body 11 so as to surround the edge portion 15c of the electrode plate 15. The sealing body 12 holds the edge portion 15c on the side surface 11a. The sealing body 12 surrounds a plurality of first sealing portions (resin portions) 21 coupled to the edge portion 15c of the electrode plate 15 and the first sealing portion 21 along the side surface 11a from the outside, and first. It has a second sealing portion 22 coupled to each of the sealing portions 21. The first sealing portion 21 and the second sealing portion 22 are, for example, alkaline-resistant insulating resins. Examples of the constituent materials of the first sealing portion 21 and the second sealing portion 22 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and the like.

The first sealing portion 21 is continuously provided on one surface 15a of the electrode plate 15 over the entire circumference of the edge portion 15c, and has a rectangular frame shape when viewed from the stacking direction D. The first sealing portion 21 is welded to one surface 15a of the electrode plate 15 of the bipolar electrode 14, the negative electrode termination electrode 18, and the positive electrode termination electrode 19 by, for example, ultrasonic waves or heat, and is airtightly bonded. The first sealing portion 21 is, for example, a film having a predetermined thickness in the stacking direction D. The inside of the first sealing portion 21 is located between the edge portions 15c of the electrode plates 15 adjacent to each other in the stacking direction D. The outside of the first sealing portion 21 projects outward from the edge of the electrode plate 15, and the tip portion thereof is embedded in the second sealing portion 22. The first sealing portions 21 adjacent to each other along the stacking direction D may be separated from each other or may be in contact with each other. The outer edge portions of the plurality of first sealing portions 21 may be welded to each other by, for example, hot plate welding. Further, the rectangular frame-shaped first sealing portion 21 may be coupled to the other surface 15b of the edge portion 15c of the electrode plate 15 of the positive electrode terminal electrode 19. In this case, the first sealing portion 21 is also coupled to the other first sealing portion 21 by the second sealing portion 22. The outer edge portion of the first sealing portion 21 may be bonded to the outer edge portion of another first sealing portion 21 by hot plate welding or the like.

The second sealing portion 22 is provided on the outside of the electrode laminate 11 and the first sealing portion 21, and constitutes the outer wall (housing) of the power storage module 4. The second sealing portion 22 is formed, for example, by injection molding of a resin, and extends along the stacking direction D over the entire length of the electrode laminate 11. The second sealing portion 22 has a rectangular frame shape extending with the stacking direction D as the axial direction. The second sealing portion 22 is welded to the outer surface of the first sealing portion 21 by heat during injection molding, for example.

The first sealing portion 21 and the second sealing portion 22 form an internal space V between adjacent electrodes and seal the internal space V. More specifically, the second sealing portion 22, together with the first sealing portion 21, is between the bipolar electrodes 14 adjacent to each other along the stacking direction D, and the negative electrode termination electrodes 18 adjacent to each other along the stacking direction D. And the bipolar electrode 14, and between the positive electrode terminal 19 and the bipolar electrode 14 adjacent to each other along the stacking direction D are sealed. As a result, an airtightly partitioned internal space V is formed between the adjacent bipolar electrodes 14, between the negative electrode termination electrode 18 and the bipolar electrode 14, and between the positive electrode termination electrode 19 and the bipolar electrode 14. ing. An electrolytic solution (not shown) containing an alkaline solution such as an aqueous potassium hydroxide solution is housed in the internal space V. The electrolytic solution is impregnated in the separator 13, the positive electrode 16, and the negative electrode 17.

Next, the electrode plate 15 will be described in more detail.

As shown in FIG. 2, the region where the edge portion 15c and the first sealing portion 21 overlap on one surface 15a of the electrode plate 15 is the coupling region K between the electrode plate 15 and the first sealing portion 21. .. In the coupling region K, the surface of the electrode plate 15 is a roughened surface (hereinafter referred to as “roughened surface R”). The roughened surface R is provided at least corresponding to the bonding region K. In the present embodiment, with respect to the electrode plate 15 of the bipolar electrode 14 and the electrode plate 15 of the positive electrode termination electrode 19, the entire one surface 15a is a roughened surface R. On the other hand, with respect to the electrode plate 15 of the negative electrode terminal electrode 18, the entire one surface 15a and the other surface 15b are roughened surfaces R. The other surface 15b of the electrode plate 15 of the negative electrode terminal electrode 18 is coupled to the first sealing portion 21 coupled to the one surface 15a of the electrode plates 15 of the bipolar electrodes 14 on the adjacent inner layer side.

The roughened surface R can be realized, for example, by forming a plurality of protrusions by electrolytic plating. As a result of the formation of a plurality of protrusions on the roughened surface R, as shown in FIG. 3, a molten resin was formed by roughening at the bonding interface between the electrode plate 15 and the first sealing portion 21. It penetrates between a plurality of protrusions P and P, and an anchor effect is exhibited. Thereby, the bond strength between the electrode plate 15 and the first sealing portion 21 can be improved. The protrusion P formed at the time of roughening has a shape in which the protrusion P formed on the surface of the electrode plate 15, for example, becomes thicker from the base end side toward the tip end with the convex portion formed on the surface of the electrode plate 15 as the base end. As a result, the cross-sectional shape between the adjacent protrusions P and P becomes an undercut shape, and the anchor effect can be enhanced.

As described above, the electrode laminate 11 includes a laminate in which a plurality of bipolar electrodes 14 are laminated, a negative electrode terminal 18 on one end side in the stacking direction D, and a positive electrode terminal 19 on the other end side in the stacking direction D. And are included. Therefore, among the plurality of electrode plates 15, the electrode plate 15 of the negative electrode terminal 18 and the electrode plate 15 of the positive electrode terminal 19 are electrode plates located in the outermost layer in the stacking direction D, and are electrodes of the bipolar electrode 14. The plate 15 is an electrode plate on the inner layer side of the outermost layer. In the following description, for convenience, the outermost electrode plate 15 is referred to as an electrode plate 15A.

In the power storage module 4, the protrusion height of the roughened surface R of the outermost electrode plate 15A (hereinafter, the roughened surface R of the outermost electrode plate is referred to as “roughened surface RA”) is the electrode plate on the inner layer side. It is larger than the protrusion height of the roughened surface R of 15. The protrusion heights of the roughened surface R and the roughened surface RA are evaluated by, for example, the maximum height Rz which is one of the parameters indicating the surface roughness. The maximum height Rz is the maximum with respect to the reference line in the cross-sectional profile by acquiring the cross-sectional profile of the roughened surface R by, for example, a non-contact roughness measuring machine using a laser microscope or a mechanical roughness measuring machine using a probe. It is calculated by finding the sum of the height Rp and the maximum depth Rv (see FIG. 3).

It is preferable that the protrusion height of the roughened surface RA of the outermost electrode plate 15A is at least twice the protrusion height of the roughened surface R of the electrode plate 15 on the inner layer side. In the present embodiment, the maximum height Rz of the roughened surface R of the electrode plate 15 on the inner layer side is 3 μm to 7 μm, whereas the maximum height Rz of the roughened surface RA of the outermost electrode plate 15A is 9 μm to 9 μm. It is about 13 μm. The height of the protrusions on the roughened surface RA and the roughened surface R can be adjusted, for example, in electrolytic plating by changing the current density and the plating solution concentration.

As described above, in the power storage module 4, the roughened surface R provided on the electrode plate 15 can increase the bonding strength between the electrode plate 15 and the first sealing portion 21. Further, in this power storage module 4, the protrusion height of the roughened surface RA of the outermost electrode plate 15A is larger than the protrusion height of the roughened surface R of the electrode plate 15 on the inner layer side. As a result, the bond strength between the electrode plate 15A of the outermost layer to which pressure is easily applied and the first sealing portion 21 is sufficiently secured, so that the withstand voltage strength can be sufficiently secured. By ensuring the withstand voltage, it is possible to suppress deformation of the electrode laminate 11 when the internal pressure rises, for example.

Further, in the present embodiment, the protrusion height of the electrode plate 15A on the outermost layer is more than twice the protrusion height of the electrode plate 15 on the inner layer side. As a result, the bonding strength between the electrode plate 15A of the outermost layer and the first sealing portion 21 is further sufficiently secured, and the withstand voltage is further improved.

Further, in the present embodiment, the negative electrode termination electrode 18 is provided at one end of the stacking direction D in the electrode laminate 11, and the positive electrode termination electrode 19 is provided at the other end of the stacking direction D in the electrode laminate 11. The electrode plate 15 of the negative electrode terminal 18 and the electrode plate 15 of the positive electrode 19 are the outermost electrode plates 15A. As a result, the bond strength between the electrode plate 15A of the negative electrode termination electrode 18 and the positive electrode termination electrode 19 located in the outermost layer of the electrode laminate 11 and the first sealing portion 21 is sufficiently secured, and the pressure resistance strength can be sufficiently secured. ..

Further, in the present embodiment, both surfaces of the electrode plate 15A of the negative electrode terminal electrode 18 are roughened surfaces R, and the other surface 15b of the electrode plate 15A is attached to the electrode plates 15 of the bipolar electrodes 14 adjacent to each other on the inner layer side. It is bonded to the bonded first sealing portion 21. In this way, the electrode plate 15A of the negative electrode terminal electrode 18 is also coupled to the first sealing portion 21 coupled to the electrode plate 15 of the bipolar electrode 14, so that the withstand voltage strength is further improved. Further, since the deformation of the first sealing portion 21 coupled to both surfaces of the electrode plate 15A of the negative electrode terminal electrode 18 is suppressed, the electrolytic solution is transferred between the electrode plate 15A and the first sealing portion 21 due to an alkaline creep phenomenon or the like. It is possible to suppress the infiltration into the binding region K and suppress the generation of leakage of the electrolytic solution.

From the viewpoint of ensuring the withstand voltage, in the electrode plate 15A of the negative electrode terminal 18 at least, the protrusion height of the roughened surface R on one side 15a is the protrusion of the roughened surface R of the electrode plate 15 on the inner layer side. It suffices if it is larger than the height, and the protrusion height of the roughened surface R on the other side 15b side may be about the same as the protrusion height of the roughened surface R of the electrode plate 15 on the inner layer side.

FIG. 4 is a schematic cross-sectional view showing the internal configuration of the power storage module according to the modified example. As shown in FIG. 2, the power storage module 34 according to the modified example is shown in FIG. 2 in that a metal plate 35 is provided on the outside of the negative electrode terminal electrode 18 at one end of the stacking direction D of the electrode laminated body 11. It is different from the power storage module 4. That is, in the power storage module 34, the metal plate 35 is arranged as the outermost layer at one end of the electrode laminate 11, and the negative electrode terminal electrode 18 is arranged as the inner layer side layer adjacent to the metal plate 35.

The metal plate 35 is made of the same metal material as the electrode plate 15 of the bipolar electrode 14, for example, and has substantially the same shape as the electrode plate 15. In the present embodiment, the metal plate 35 is a rectangular metal foil made of nickel, and is an uncoated electrode plate in which neither the positive electrode 16 nor the negative electrode 17 is coated. Similar to the electrode plate 15, the first sealing portion 21 is coupled to the edge portion 35c on the one side 35a side of the metal plate 35. The metal plate 35 is also coupled to the first sealing portion 21 coupled to the electrode plate 15 of the negative electrode terminal electrode 18. That is, in the metal plate 35, both one surface 35a and the other surface 35b are in a state of being bonded to the first sealing portion 21.

Both one surface 35a and the other surface 35b of the metal plate 35 are roughened surfaces R. In this modification, the roughened surface R of the metal plate 35 and the roughened surface R of the electrode plate 15 of the positive electrode end electrode 19 form the roughened surface RA of the outermost layer, and the protrusion height of the roughened surface RA. Is larger than the protrusion height of the roughened surface R of the electrode plate 15 on the inner layer side. In the metal plate 35, at least the protrusion height of the roughened surface R on the one side 35a side may be larger than the protrusion height of the roughened surface R on the inner layer side, and the other side 15b side. The protrusion height of the roughened surface R may be about the same as the protrusion height of the roughened surface R of the electrode plate 15 on the inner layer side.

Further, the height of the protrusion of the roughened surface R of the electrode plate 15 of the negative electrode terminal 18 located on the outer layer side next to the metal plate 35 is the protrusion of the roughened surface RA of the electrode plate 15 of the metal plate 35 and the positive electrode 19. It may be about the same as the height, or may be about the same as the protrusion height of the roughened surface R of the electrode plate 15 of the bipolar electrode 14. Here, the other surface 15b of the electrode plate 15 of the negative electrode terminal electrode 18 does not necessarily have to be coupled to the first sealing portion 21 coupled to the electrode plates 15 of the bipolar electrodes 14 adjacent to each other on the inner layer side. .. In this case, only one surface 15a of the electrode plate 15 of the negative electrode terminal electrode 18 may be a roughened surface R.

Even in such a modification, the protrusion height of the roughened surface RA of the metal plate 35 and the electrode plate 15A of the positive electrode end electrode 19 which is the outermost layer becomes the protrusion height of the roughened surface R of the electrode plate 15 on the inner layer side. It is larger than that. As a result, the bonding strength between the outermost metal plate 35 and the electrode plate 15A to which pressure is easily applied and the first sealing portion 21 is sufficiently secured, so that the withstand voltage strength can be sufficiently secured.

Further, in this modification, the metal plate 35 can supplement the rigidity of the first sealing portion 21 coupled to the electrode plate 15 of the negative electrode termination electrode 18, and the deformation of the first sealing portion 21 can be suppressed. .. Therefore, it is possible to suppress the infiltration of the electrolytic solution into the bonding region K between the electrode plate 15 and the first sealing portion 21 due to the alkaline creep phenomenon or the like, and it is possible to suppress the generation of leakage of the electrolytic solution. Further, when the metal plate 35, the electrode plate 15 of the negative electrode terminal 18 and the first sealing portion 21B form a surplus space S (see FIG. 4) different from the internal space V, the surplus space S is formed. Is a buffer space for water intrusion from the outside. In this case, the effect of suppressing the progress of the alkaline creep phenomenon is further exhibited.

4,34 ... Energy storage module, 11 ... Electrode laminate, 11a ... Side surface, 12 ... Sealed body, 14 ... Bipolar electrode, 15, 15A ... Electrode plate, 15a ... One side, 15b ... The other side, 15c ... Edge, 18 ... Negative electrode terminal electrode, 19 ... Positive electrode terminal electrode, 21 ... First sealing part (resin part), 35 ... Metal plate, 35a ... One side, 35b ... Other side, 35c ... Edge part, R, RA ... Roughening Surface, P ... protrusion.

Claims (7)

An electrode laminate in which multiple bipolar electrodes are laminated, and
A sealing body provided so as to surround the side surface of the electrode laminated body and sealing between the bipolar electrodes is provided.
The sealed body has a plurality of resin portions bonded to the edges on one side of the electrode plate included in the electrode laminate.
The electrode plate has a roughened surface at least in a bonding region with the resin portion.
The protrusion height of the roughened surface of the electrode plate located in the outermost layer in the stacking direction in the electrode laminate is larger than the protrusion height of the roughened surface of the electrode plate on the inner layer side of the outermost layer. Power storage module. The power storage module according to claim 1, wherein the protrusion height of the electrode plate on the outermost layer is at least twice the protrusion height of the electrode plate on the inner layer side. A negative electrode terminal electrode is provided at one end of the electrode laminate in the stacking direction.
A positive electrode terminal electrode is provided at the other end of the electrode laminate in the stacking direction.
The power storage module according to claim 1 or 2, wherein the electrode plate of the negative electrode terminal electrode and the electrode plate of the positive electrode terminal electrode are the electrode plates of the outermost layer. Both sides of the electrode plate of the negative electrode terminal electrode are the roughened surfaces.
The power storage module according to claim 3, wherein the other surface of the electrode plate is coupled to a resin portion bonded to the electrode plates of adjacent bipolar electrodes. A negative electrode terminal electrode and a metal plate located outside the negative electrode terminal electrode are provided at one end of the electrode laminate in the stacking direction.
A positive electrode terminal electrode is provided at the other end of the electrode laminate in the stacking direction.
The power storage module according to claim 1 or 2, wherein the metal plate and the electrode plate of the positive electrode terminal electrode are the outermost metal plate. Both sides of the metal plate are the roughened surfaces.
The power storage module according to claim 5, wherein the other surface of the metal plate is coupled to a resin portion bonded to the electrode plate of the negative electrode terminal electrode. Both sides of the electrode plate of the negative electrode terminal electrode are the roughened surfaces.
The power storage module according to claim 5 or 6, wherein the other surface of the electrode plate is coupled to a resin portion bonded to the electrode plates of adjacent bipolar electrodes.

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