JP7123717B2 - storage module - Google Patents

Description

The present invention relates to an electric storage module.

As a conventional power storage module, a bipolar battery is known which includes a bipolar electrode in which a positive electrode is formed on one side of an electrode plate and a negative electrode is formed on the other side (see Patent Document 1). A bipolar battery has a laminate formed by laminating a plurality of bipolar electrodes with separators interposed therebetween. A sealing body is provided on the side surface of the laminate for sealing between the bipolar electrodes adjacent to each other in the stacking direction, and the internal space formed between the bipolar electrodes contains an electrolytic solution.

JP 2011-204386 A

By the way, the present inventors have obtained the following findings while earnestly studying the performance improvement of the electric storage module as described above. That is, in the electric storage module as described above, hydrogen is generated on the negative electrode due to the water in the electrolyte solution during the initial charge. When the negative electrode contains a hydrogen-absorbing alloy, this hydrogen is absorbed by the negative electrode. However, since the hydrogen absorption state is unstable under the internal pressure during normal use, the negative electrode discharges a certain amount of hydrogen. Therefore, hydrogen is present in the internal space. If hydrogen permeates from the internal space to the outside, the self-discharge performance may deteriorate.

The present invention has been made based on the above findings, and an object of the present invention is to provide an electricity storage module capable of suppressing deterioration in self-discharge performance.

A power storage module according to the present invention includes a laminate including a plurality of electrodes laminated along a first direction, an electrolytic solution containing water disposed in a plurality of internal spaces of the laminate, and peripheral edges of the electrodes. a body portion having a plurality of first resin portions provided in the body portion; and a second resin portion provided so as to surround the first resin portion and sealing an internal space together with the first resin portion; The first resin portion includes an annular extension portion extending from the peripheral portion to the outside of the electrode as viewed in the first direction, and covers the extension portion as viewed in the first direction at least outside the main body portion in the first direction. A ring-shaped metal foil is provided as shown in FIG.

In this power storage module, the first resin portion is provided on the peripheral portion of the electrode. Further, a second resin portion is provided so as to surround the first resin portion. The first resin portion and the second resin portion cooperate to seal the internal space in which the electrolytic solution is placed. The first resin portion includes an extension portion extending from the peripheral portion of the electrode to the outside of the electrode when viewed from the stacking direction (first direction) of the electrode. Therefore, when viewed from the first direction, the body portion includes a region that overlaps with the electrode and a region that is exposed from the electrode and overlaps with the extension portion of the first resin portion. Hydrogen permeation is less likely to occur from the region overlapping the electrodes in the main body. On the other hand, it is considered that hydrogen permeation tends to occur along the first direction from the region of the main body exposed from the electrode. On the other hand, in this power storage module, the metal foil is further provided outside the main body in the region that overlaps with the extension when viewed from the first direction. Therefore, permeation of hydrogen from the region is also suppressed. As a result, according to this power storage module, deterioration in self-discharge performance is suppressed.

In the power storage module according to the present invention, the metal foil may include an outer foil provided outside the second resin portion in the first direction. At this time, the outer foil may consist of a plurality of linear portions arranged along the annular shape of the extension. In this case, when manufacturing the outer foil that is annular when viewed from the first direction, the waste rate of the base material can be reduced compared to the case where the annular member is cut out from the base material.

In the power storage module according to the present invention, the metal foil may be roughened and bonded to the second resin portion. Alternatively, in the power storage module according to the present invention, a resin layer may be interposed between the metal foil and the second resin portion. In this manner, the metal foil may be directly bonded to the resin portion, or the metal foil may be bonded to the resin portion via the resin layer.

In the power storage module according to the present invention, the metal foil may include an intermediate foil provided between the main body portion and the second resin portion in the first direction. At this time, the electrode plate of the electrode is exposed at the outermost part of the main body in the first direction, and a resin layer may be interposed between the intermediate foil and the electrode plate. In this way, when the intermediate foil is arranged between the main body and the second resin part, the resin layer is interposed between the outermost electrode plate of the main body and the intermediate foil. Sealability can be improved.

ADVANTAGE OF THE INVENTION According to this invention, the electrical storage module which can suppress the fall of self-discharge performance can be provided.

1 is a schematic cross-sectional view showing an embodiment of a power storage device; FIG. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. 1; FIG. 3 is an enlarged view of a main part of the power storage module shown in FIG. 2; 4 is a schematic plan view of the power storage module shown in FIG. 2. FIG. It is a principal part enlarged view of the electrical storage module which concerns on a modification.

An embodiment will be described in detail below with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description may be omitted. Also, each drawing may show an orthogonal coordinate system S defined by the X-axis, the Y-axis, and the Z-axis.

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

The module laminate 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, for example, a bipolar battery, and has a rectangular shape when viewed from the stacking direction D. As shown in FIG. The 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 is exemplified.

Electricity storage modules 4 adjacent to each other in the stacking direction are electrically connected via conductive plates 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 module 4 located at the end of the stack in the stacking direction. A positive electrode terminal 6 is connected to one of the conductive plates 5 arranged on the outer side in the stacking direction of the storage module 4 positioned at the end of the stack. A negative electrode terminal 7 is connected to the other conductive plate 5 arranged outside in the stacking direction of the storage module 4 positioned at the end of the stack. The positive electrode terminal 6 and the negative electrode terminal 7 are pulled out, for example, from the edge of the conductive plate 5 in a direction intersecting the stacking direction. The power storage device 1 is charged and discharged by the positive terminal 6 and the negative terminal 7 .

Inside the conductive plate 5, a plurality of flow paths 5a for circulating a coolant such as air are provided. The flow path 5 a extends along a direction that intersects (perpendicularly) with, for example, the stacking direction and the lead-out direction of the positive electrode terminal 6 and the negative electrode terminal 7 . The conductive plate 5 functions not only as a connecting member that electrically connects the storage modules 4, but also as a radiator plate that dissipates the heat generated in the storage modules 4 by circulating the coolant through the flow paths 5a. Combine functions. In the example of FIG. 1, the area of the conductive plate 5 when viewed from the stacking direction is smaller than the area of the storage module 4, but from the viewpoint of improving heat dissipation, the area of the conductive plate 5 is equal to the area of the storage module 4. , or may be larger than the area of the power storage module 4 .

The restraining member 3 is composed of a pair of end plates 8 sandwiching the module stack 2 in the stacking direction, and fastening bolts 9 and nuts 10 fastening the end plates 8 together. The end plate 8 is a rectangular metal plate having an area slightly larger than the area of the storage module 4 and the conductive plate 5 when viewed in the stacking direction. An electrically insulating film F is provided on the inner side surface of the end plate 8 in the stacking direction (the side facing the module stack 2). The film F insulates between the end plate 8 and the conductive plate 5 .

The end plate 8 is provided with an insertion hole 8a at an edge portion on the outer peripheral side of the portion overlapping the module stack 2 in the stacking direction. 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 the tip portion of the fastening bolt 9 protruding from the insertion hole 8a of the other end plate 8 has a , a nut 10 is screwed. As a result, the storage module 4 and the conductive plate 5 are sandwiched between the end plates 8 to form a module laminate 2 as a unit, and a binding 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. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. 1. FIG. As shown in FIG. 2 , the power storage module 4 includes an electrode laminate (laminate) 11 and a resin sealing body 12 that seals the electrode laminate 11 . The electrode laminate 11 includes a plurality of electrodes (a plurality of bipolar electrodes 14, a single negative terminal electrode 18, and a single positive terminal electrode 19). Here, the stacking direction D of the electrode stack 11 coincides with the stacking direction of the module stack 2 .

The bipolar electrode 14 includes an electrode plate 15, a positive electrode 16 provided on a first surface 15a of the electrode plate 15, and a negative electrode 17 provided on a second surface 15b of the electrode plate 15 opposite to the first surface 15a. The positive electrode 16 is a positive electrode active material layer formed by coating the electrode plate 15 with a positive electrode active material. The negative electrode 17 is a negative electrode active material layer formed by coating the electrode plate 15 with a negative electrode active material. In the electrode stack 11 , the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of another bipolar electrode 14 adjacent in the stacking direction D with the separator 13 interposed therebetween. In the electrode stack 11 , the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of another bipolar electrode 14 adjacent in the stacking direction D with the separator 13 interposed therebetween.

The negative terminal electrode 18 includes the electrode plate 15 and the negative electrode 17 provided on the second surface 15 b of the electrode plate 15 . The negative terminal electrode 18 is arranged at one end in the stacking direction D so that the second surface 15b faces the inside of the electrode stack 11 (the center side in the stacking direction D). The negative electrode 17 of the negative terminal electrode 18 faces the positive electrode 16 of the bipolar electrode 14 at one end in the stacking direction D with the separator 13 interposed therebetween. The positive terminal electrode 19 includes the electrode plate 15 and the positive electrode 16 provided on the first surface 15 a of the electrode plate 15 . The positive terminal electrode 19 is arranged at the other end in the stacking direction D so that the first surface 15 a faces the inside of the electrode stack 11 . The positive electrode 16 of the positive terminal electrode 19 faces the negative electrode 17 of the bipolar electrode 14 at the other end in the stacking direction D with the separator 13 interposed therebetween.

The conductive plate 5 is in contact with the first surface 15 a of the electrode plate 15 of the negative terminal electrode 18 . Also, the second surface 15b of the electrode plate 15 of the positive terminal electrode 19 is in contact with the conductive plate 5 of the adjacent electricity storage module 4 . A binding load from the binding member 3 is applied to the electrode laminate 11 from the negative terminal electrode 18 and the positive terminal electrode 19 via the conductive plate 5 . That is, the conductive plate 5 is also a restraining member that applies a restraining load to the electrode laminate 11 along the lamination direction D. As shown in FIG.

The electrode plate 15 is made of metal such as nickel or nickel-plated steel plate, for example. As an example, the electrode plate 15 is a rectangular metal foil made of nickel. A peripheral edge portion 15c of the electrode plate 15 (an edge portion of the bipolar electrode 14, the negative electrode terminal electrode 18, and the positive electrode terminal electrode 19) 15c has a rectangular frame shape and is an uncoated area where the positive electrode active material and the negative electrode active material are not coated. It has become. Examples of the positive electrode active material forming the positive electrode 16 include nickel hydroxide. Examples of negative electrode active materials that constitute the negative electrode 17 include hydrogen storage alloys. In this embodiment, the formation area of the negative electrode 17 on the second surface 15 b of the electrode plate 15 is one size larger than the formation area of the positive electrode 16 on the first surface 15 a of the electrode plate 15 .

The separator 13 is formed in a sheet shape, for example. Examples of the separator 13 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or nonwoven fabrics made of polypropylene, methyl cellulose, and the like. The separator 13 may be reinforced with a vinylidene fluoride resin compound.

The sealing body 12 is made of, for example, an insulating resin, and is formed into a frame shape having a substantially rectangular cross section as a whole. The sealing body 12 is provided along the side surface of the electrode laminate 11 so as to surround the peripheral portion 15c. The sealing body 12 holds the peripheral portion 15c. The sealing body 12 includes a plurality of first resin portions (resin frame) 21 welded to the peripheral portion 15c, and a first resin portion 21 so as to surround the first resin portions 21 from the outside (outside when viewed from the stacking direction D). and a single second resin portion 22 joined to the resin portion 21 . The first resin portion 21 and the second resin portion 22 are, for example, an insulating resin and may be made of polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), or the like.

The first resin portion 21 is formed in a rectangular frame shape (rectangular ring shape). The first resin portion 21 is provided continuously over the entire circumference of the peripheral portion 15c. The first resin portion 21 is joined (for example, welded) to the first surface 15 a of the electrode plate 15 in an airtight and liquid-tight manner. The first resin portion 21 is welded by, for example, ultrasonic waves or heat. The first resin portion 21 is a film having a predetermined thickness (length in the stacking direction D). The end face of the electrode plate 15 is exposed without being covered with the first resin portion 21 . The inner end portion of the first resin portion 21 is positioned between the peripheral edge portions 15c of the electrode plates 15 that are adjacent to each other in the stacking direction D, and the outer end portion extends outward from the electrode plate 15 when viewed in the stacking direction D. overhanging. The first resin portion 21 is embedded in the second resin portion 22 at the outer end. The first resin portions 21 adjacent to each other along the stacking direction D are separated from each other.

Here, multiple types of first resin portions 21 (first resin portions 23 and 25) are used. The first resin portion 23 is provided on the first surface 15 a of the negative terminal electrode 18 at the peripheral edge portion 15 c of the negative terminal electrode 18 . Also, the first resin portion 23 is provided on the second surface 15 b of the positive terminal electrode 19 . Here, the first resin portion 23 is formed from a single frame-shaped portion having a rectangular cross section. The first resin portion 25 is provided on the first surface 15 a of the bipolar electrode 14 and the first surface 15 a of the positive terminal electrode 19 at the peripheral edge portion 15 c of the bipolar electrode 14 and the positive terminal electrode 19 .

The first resin portion 25 includes a first layer 27 that is a frame-shaped portion with a rectangular cross section, and a second layer 29 that is a frame-shaped portion with a rectangular cross section and is laminated on the first layer 27 . Each of the first layer 27 and the second layer 29 is a frame-shaped resin film. The first resin portion 25 is joined to the first surface 15 a at the first layer 27 . The outer edge of the first layer 27 and the outer edge of the second layer 29 match when viewed from the stacking direction D. As shown in FIG. On the other hand, the inner edge of the first layer 27 and the inner edge of the second layer 29 are separated from each other when viewed in the stacking direction D. As a result, a stepped portion on which the separator 13 is arranged is formed in the first resin portion 25 .

3 is an enlarged view of a main part of the power storage module shown in FIG. 2. FIG. 4 is a schematic plan view of the power storage module shown in FIG. 2. FIG. A more detailed description will be given with reference to FIGS. Here, one end of the storage module 4 in the stacking direction D (that is, the end on the negative terminal electrode 18 side) will be described, but the other end in the stacking direction D (that is, the positive terminal electrode 19 side) will be described. The same is true for the end of ).

As described above, the electrolyte solution is placed in the internal space V of the electrode laminate 11 . The electrolytic solution contains water, for example, an alkaline aqueous solution such as an aqueous potassium hydroxide solution. That is, the power storage module 4 includes a plurality of electrodes (a plurality of bipolar electrodes 14, a single negative terminal electrode 18, and a single positive terminal electrode 19) stacked along the stacking direction D (first direction). an electrode laminate 11 containing the electrode laminate 11, an electrolytic solution containing water disposed in the plurality of internal spaces V of the electrode laminate 11, and a plurality of first resin portions 21 provided on the peripheral edge portions 15c of the electrodes. These constitute the body part 20 in this embodiment.

As described above, the outer end portion of the first resin portion 21 (the first resin portion 23 in the example of FIG. 3) protrudes outward from the electrode plate 15 when viewed in the stacking direction D. As shown in FIG. That is, the first resin portion 21 includes a rectangular annular (frame-like) extending portion 21p extending from the peripheral edge portion 15c to the outside of the electrode (the negative terminal electrode 18 in the example of FIG. 3) when viewed in the stacking direction D. The extension part 21 p is a part that protrudes from the electrode and is not embedded in the second resin part 22 . In other words, the extending portion 21p is a portion that overlaps the area RA between the outer end surface 15e of the electrode plate 15 and the inner surface 22s of the second resin portion 22 when viewed in the stacking direction D. The inner side surface 22s is a surface facing the end surface 15e. The electrode plate 15 is not arranged in the area RA.

A rectangular annular (frame-shaped) metal laminate film 30 is provided outside the body portion 20 in the stacking direction D so as to cover the extending portion 21p (area RA) when viewed in the stacking direction D. The metal laminate film 30 includes a metal foil 31 and a pair of resin layers 32 and 33 laminated on the metal foil 31 so as to sandwich the metal foil 31 therebetween. Here, the metal laminate film 30 is provided outside the second resin portion 22 in the lamination direction D. As shown in FIG. That is, the metal laminate film 30 includes an outer foil (metal foil 31) provided outside the second resin portion 22 in the lamination direction D. As shown in FIG. A resin layer 32 is interposed between the outer foil and the second resin portion 22 . The metal laminate film 30 is joined (for example, welded) to the second resin portion 22 at the resin layer 32 .

The metal foil 31 is made of metal such as aluminum or nickel, for example. Moreover, the resin layer 32 is made of a resin having compatibility with the second resin portion 22, and is made of, for example, a polyolefin-based resin (eg, polyethylene or polypropylene). The material of the resin layer 33 is not required to be compatible with the second resin portion 22, but can be selected from materials similar to those of the resin layer 32, for example. Furthermore, here, since the metal laminate film 30 is provided further outside the second resin portion 22, the material of each portion of the metal laminate film 30 can be any material other than the above materials without considering the resistance to the electrolytic solution. can also be selected from materials of

The range in which the metal laminate film 30 (metal foil 31) is provided may be a range including at least the region RA when viewed from the stacking direction D. Here, the metal laminate film 30 extends from the region RA beyond the outer end surface 15e of the electrode plate 15 to the inside when viewed from the stacking direction D, and extends from the region RA to the inner surface 22s of the second resin portion 22. beyond and extends to the outside. That is, the metal laminate film 30 also overlaps the portion of the first resin portion 21 embedded in the second resin portion 22 beyond the extending portion 21p when viewed from the stacking direction D. As shown in FIG.

In addition, the inner end surface 30b of the metal laminate film 30 is located inside the inner end surface 22e of the second resin portion 22, and the outer end surface 30a of the metal laminate film 30 is located inside the inner surface 22s of the second resin portion 22. located outside the The metal laminate film 30 may be provided so that its end face 30b reaches the end face 22e of the second resin portion 22, or may be provided so as to be located inside beyond the end face 22e of the end face 30b. . Furthermore, the metal laminate film 30 may be provided so that the end surface 30a reaches the outer edge of the second resin portion 22 when viewed from the lamination direction D. As shown in FIG. The thickness (dimension in the stacking direction D) of the metal foil 31 is approximately the same as that of the electrode plate 15, for example. The thickness (dimension in the stacking direction D) of the metal foil 31 is, for example, about 10 μm to 50 μm.

As described above, in the storage module 4, the first resin portion 21 is provided on the peripheral edge portion 15c of the electrodes (the bipolar electrode 14, the negative terminal electrode 18, and the positive terminal electrode 19). Furthermore, a second resin portion 22 is provided so as to surround the first resin portion 21 . The first resin portion 21 and the second resin portion 22 cooperate to seal the internal space V in which the electrolytic solution is placed. The first resin portion 21 includes an extension portion 21p extending from the peripheral portion 15c of the electrode to the outside of the electrode when viewed from the stacking direction D (first direction) of the electrode.

Therefore, when viewed from the stacking direction D, the body portion 20 includes a region overlapping with the electrode and a region RA exposed from the electrode and overlapping with the extension portion 21p of the first resin portion 21 . Hydrogen permeation is less likely to occur from the region of the main body 20 that overlaps with the electrode. On the other hand, it is considered that hydrogen permeation is likely to occur along the stacking direction D from the region RA exposed from the electrode in the main body 20 . On the other hand, in the electric storage module 4, the metal foil 31 is further provided outside the main body portion 20 in the region RA that overlaps with the extension portion 21p when viewed in the stacking direction D. As shown in FIG. Therefore, permeation of hydrogen from the region RA is also suppressed. As a result, according to the power storage module 4, deterioration in self-discharge performance is suppressed. Further, by providing the metal laminate film 30 (metal foil 31) having higher rigidity than the second resin portion 22 on the outside of the main body portion 20, the strength against pressure can be improved.

The above embodiment describes one embodiment of the storage module according to the present invention. Therefore, the power storage module according to the present invention is not limited to the example described above, and can be arbitrarily modified.

For example, as in the above embodiment, when the metal laminate film 30 is provided outside the second resin portion 22 and does not contribute to the sealing of the internal space V (sealing of the electrolytic solution except hydrogen permeation), the metal The laminate film 30 is not limited to being integrally formed in an annular shape when viewed from the lamination direction D. That is, the metal laminate film 30 may be composed of a plurality of linear portions arranged along the ring of the extending portion 21p (region RA). In this case, it is not required that the straight portions are strictly joined together, and a gap may be interposed between the straight portions. According to this configuration, when manufacturing the metal laminate film 30 (metal foil 31) having an annular shape when viewed from the stacking direction D, the waste rate of the base material is reduced compared to the case where the annular member is cut out from the base material. can.

Moreover, if the metal laminate film 30 does not contribute to sealing the internal space V, the metal laminate film 30 may not have the resin layer 32 . In this case, the surface of the metal foil 31 is roughened (for example, roughened plating is applied), and the metal foil 31 is directly joined (welded) to the second resin portion 22 . In this case, the resin layer 33 may not be provided, and only the metal foil 31 may be used.

Here, FIG. 5 is an enlarged view of a main part of the power storage module according to the modification. In the example shown in FIG. 5 as well, a rectangular annular (frame-like) metal laminate film 30 is provided outside the body portion 20 in the stacking direction D so as to cover the extending portion 21p (area RA) when viewed from the stacking direction D. is provided. In this example, the metal laminate film 30 is provided between the main body portion 20 and the second resin portion 22 in the lamination direction D. As shown in FIG. That is, the metal laminate film 30 includes an intermediate foil (metal foil 31) provided between the main body portion 20 and the second resin portion 22 in the lamination direction D. As shown in FIG.

Here, a metal laminate film 30 is arranged instead of the first resin portion 23 in FIG. More specifically, the electrode plate 15 of the electrodes (the negative terminal electrode 18 and the positive terminal electrode 19) is exposed at the outermost part of the main body 20 in the stacking direction D, and the exposed portion of the electrode plate 15 is A metal laminate film 30 is provided against it. In other words, the resin layer 32 is interposed between the metal foil 31 (intermediate foil) and the electrode plate 15 .

In this case, the metal laminate film 30 contributes to sealing of the internal space V (sealing of the electrolytic solution). Therefore, in this example, it is effective to use not only the metal foil 31 but also a laminate film in which the metal foil 31 is provided with the resin layers 32 and 33 in order to secure the sealability with the first resin portion 21 . . Also, from the viewpoint of ensuring sealing performance, it is effective here to form the metal laminate film 30 in a ring shape continuously along the ring shape of the extending portion 21p (region RA). In this example, the inner end face 30b of the metal laminate film 30 is located inside the inner end face 22e of the second resin portion 22. As shown in FIG.

As described above, the example shown in FIG. 5 also provides the same effects as the above embodiment. Further, when the metal foil 31 is arranged between the body portion 20 and the second resin portion 22 , the resin layer 32 should be interposed between the outermost electrode plate 15 of the body portion 20 and the metal foil 31 . Therefore, the sealing performance can be improved.

The metal laminate film 30 may be provided both outside the second resin portion 22 in the lamination direction D and between the main body portion 20 and the second resin portion 22 in the lamination direction D. That is, the power storage module 4 may include both outer foils and intermediate foils. In addition, the metal foil 31 (metal laminate film 30) corresponding to the outer foil is not limited to the position on the second resin portion 22 in the lamination direction D, but extends over the outer surface of the second resin portion 22 intersecting the lamination direction D. may be provided.

Furthermore, in the above-described embodiment, a mode in which the negative terminal electrode 18 is arranged at the outermost part of one end of the main body part 20 in the stacking direction D is exemplified. However, the body portion 20 may include a metal plate provided further outside the negative terminal electrode 18 in the stacking direction D. As shown in FIG. In this case, the metal plate can be joined (for example, welded) to the first resin portion 21 (first resin portion 23) joined to the first surface 15a of the negative terminal electrode 18 at its peripheral portion. The electrode plate 15 can be used as the metal plate. By providing the metal plate in this manner, the electrolyte solution is prevented from seeping out to the outer surface side due to the so-called alkali creep phenomenon.

4 power storage module 11 electrode laminate (laminate) 15 electrode plate 15c peripheral portion 14 bipolar electrode (electrode) 18 negative terminal electrode (electrode) 19 positive terminal electrode (electrode) , 20... main body part, 21... first resin part, 21p... extension part, 22... second resin part, 31... metal foil (intermediate foil, outer foil), 32... resin layer, V... internal space.

Claims (7)

A power storage module that is a nickel-metal hydride secondary battery,
A laminate including a plurality of electrodes laminated along a first direction, an electrolytic solution containing water arranged in a plurality of internal spaces of the laminate, and a plurality of electrodes provided at the peripheral edge of each of the electrodes a body portion having a first resin portion;
a second resin portion provided to surround the first resin portion and for sealing the internal space together with the first resin portion;
with
the first resin portion includes an annular extension portion extending from the peripheral portion to the outside of the electrode when viewed from the first direction;
A ring-shaped metal foil is provided at least outside the body portion in the first direction so as to cover the extension portion when viewed from the first direction,
storage module. The metal foil includes an outer foil provided outside the second resin portion in the first direction,
The power storage module according to claim 1. The outer foil consists of a plurality of linear portions arranged along the annular shape of the extension,
The power storage module according to claim 2. The metal foil is roughened and joined to the second resin part,
The power storage module according to claim 2 or 3. A resin layer is interposed between the metal foil and the second resin portion,
The power storage module according to claim 2 or 3. The metal foil includes an intermediate foil provided between the body portion and the second resin portion in the first direction,
The electricity storage module according to any one of claims 1 to 5. An electrode plate of the electrode is exposed at the outermost part of the main body in the first direction,
A resin layer is interposed between the intermediate foil and the electrode plate,
The power storage module according to claim 6.

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