JP6897124B2 - Power storage module - Google Patents

Description

The present invention relates to a power storage module.

There is known a power storage module having a laminate in which a positive electrode is provided on one side of an electrode plate and a bipolar electrode is provided on the other side. For example, in Patent Document 1, in a bipolar battery (storage module) in which a laminated body is housed in a battery exterior material, a current collector (electrode plate) of a bipolar electrode is laminated via a seal layer. Further, in the laminated body, the seal layer is provided so as to surround the peripheral edge portion of the current collector, and the adjacent seal layers are further adhered to each other.

Japanese Unexamined Patent Publication No. 2005-190713

In the above-mentioned power storage module, improvement in airtightness is desired. Therefore, it is conceivable to provide a second seal layer (second seal portion) that surrounds the side surfaces of all the seal layers (first seal portion) and holds all the seal layers.

However, when the second seal portion surrounding all the first seal portions is formed by injection molding, the periphery of the first seal portion cannot be pressed by a mold or the like, so that the second seal portion cannot be pressed by injection molding. Due to the flow of the resin, the outer edge portion of the first seal portion arranged on the end side in the stacking direction of the laminated body may be rolled up. In such a case, the second seal portion cannot sufficiently surround the rolled-up first seal portion, or the rolled-up portion may not be filled with the resin of the second seal portion. A gap may be formed between the 1st seal portion and the 2nd seal portion, which may reduce the airtightness of the power storage module.

An object of the present invention is to provide a power storage module capable of suppressing a decrease in airtightness due to curling up of a first seal portion.

The power storage module according to the present invention has a bipolar electrode including a positive electrode layer provided on one surface of the electrode plate and the electrode plate and a negative electrode layer provided on the other surface of the electrode plate, and one surface of the electrode plate and the electrode plate. A power storage module having a positive electrode side terminal electrode including a positive electrode layer provided and a negative electrode side terminal electrode including an electrode plate and a negative electrode layer provided on one surface of the electrode plate , wherein the bipolar electrode serves as a separator. It has a bipolar electrode group laminated via the electrode , a positive electrode side terminal electrode arranged at one end of the bipolar electrode group in the stacking direction, and a negative electrode side terminal electrode arranged at the other end of the bipolar electrode group in the stacking direction. , A laminated body in which a frame- shaped first seal portion is bonded to the peripheral edge of each electrode plate of the bipolar electrode, the positive electrode side terminal electrode, and the negative electrode side terminal electrode, and arranged at both ends of the laminated body in the stacking direction. A second conductive plate is arranged so as to cover the pair of conductive plates , the side surfaces of the laminate extending in the stacking direction, and the peripheral edges of the pair of conductive plates, and the first seal portion and the conductive plate are integrally joined. It is provided with a seal portion.

The power storage module includes conductive plates arranged at both ends of the laminated body in the stacking direction. The second seal portion surrounds the conductive plate and the laminated body together, and integrally holds the conductive plate and the first seal portion. Therefore, when such a second seal portion is formed by, for example, injection molding, the first seal portion that holds the peripheral edge portion of the electrode plate arranged on the outermost layer can be pressed by the conductive plate, or the second seal portion can be pressed. Since the impact due to the flow of the resin to the first seal portion is alleviated by the conductor, it is possible to prevent the first seal portion from rolling up. Therefore, the first seal portions can be sufficiently connected to each other by the second seal portion. As described above, it is possible to suppress a decrease in the airtightness of the power storage module.

In the power storage module according to the present invention, a frame-shaped third seal portion is bonded to the peripheral edge portion of the conductive plate, and the conductive plate is bonded to the second seal portion via the third seal portion. May be good. In this case, since the third seal portion is arranged on the end side of the first seal portion arranged on the end side of the laminated body, the rigidity is higher than the other portions at both ends in the stacking direction of the laminated body. Parts can be formed. Therefore, at the time of injection molding of the second seal portion, the first seal portion arranged on the end side of the laminated body is further suppressed from being rolled up.

The power storage module according to the present invention further includes a conductive member interposed between the laminated body and the conductive plate, and the conductive member is arranged inside the inner side surface of the first seal portion when viewed from the stacking direction. You may be. The thicker the conductive plates arranged at both ends of the laminated body, the more effective it is to suppress the curling up of the first seal portion. In this configuration, by interposing a conductive member between the laminated body and the conductive plate, the same effect as increasing the thickness of the conductive plate can be obtained. Further, in this configuration, a conductive member having a volume smaller than the amount of increase in the volume of the conductive plate when the thickness of the conductive plate is increased is interposed. Thereby, when the material of the conductive member is the same as the material of the conductive plate, the cost can be reduced.

In the power storage module according to the present invention, the conductive plate and the electrode plate may be formed of the same material and have the same dimensions and shape as viewed from the stacking direction and the direction intersecting the stacking direction. .. In this case, since the electrode plate of the bipolar electrode can also be used as the conductive plate, it is possible to save the trouble of preparing a separate member as the conductive plate.

In the power storage module according to the present invention, two or more conductive plates may be continuously laminated in the stacking direction on at least one of one end side and the other end side of the laminated body in the stacking direction. In this case, the thickness can be adjusted to an arbitrary value by continuously laminating two or more conductive plates.

According to the present invention, it is possible to suppress a decrease in airtightness due to curling up of the first seal portion.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a power storage device including a power storage module. FIG. 2 is a schematic cross-sectional view showing the power storage module of FIG. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is a schematic cross-sectional view showing a power storage module according to a modified example. FIG. 5 is a schematic cross-sectional view showing a power storage module according to a modified example. FIG. 6 is a schematic cross-sectional view showing a power storage module according to a modified example.

Hereinafter, the power storage module according to the embodiment of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements or the corresponding elements may be designated by the same reference numerals, and duplicate description may be omitted. Further, in each figure, the Cartesian coordinate system S defined by the X-axis, the Y-axis, and the Z-axis may be shown.

The power storage device 10 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage module 12 is, for example, a bipolar battery. Examples of the power storage module 12 include a secondary battery such as a nickel hydrogen secondary battery and a lithium ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery will be illustrated.

The plurality of power storage modules 12 are laminated via a conductor 14 such as a metal plate to form an array 11. The conductor 14 is one metal body arranged between the electricity storage modules 12 and 12 adjacent to each other, and is arranged in contact with both the electricity storage modules 12 and 12 adjacent to each other. The conductor 14 is formed of, for example, a metal material such as aluminum or copper. When viewed from the stacking direction (Z direction), the power storage module 12 and the conductor 14 have, for example, a rectangular shape. When viewed from the stacking direction, the conductor 14 is smaller than the power storage module 12, but may be the same as or larger than the power storage module 12. The conductor 14 is electrically connected to the adjacent power storage module 12. As a result, the plurality of power storage modules 12 are connected in series in the stacking direction.

The conductors 14 are also arranged on the outside of the power storage modules 12 located at both ends in the stacking direction of the power storage modules 12. That is, the conductors 14 are also arranged at both ends of the array 11 in the stacking direction. In the stacking direction, the positive electrode terminal 24 is connected to the conductor 14 located at one end, and the negative electrode terminal 26 is connected to the conductor 14 located at the other end. The positive electrode terminal 24 may be integrated with the conductor 14 to be connected. The negative electrode terminal 26 may be integrated with the conductor 14 to be connected. The positive electrode terminal 24 and the negative electrode terminal 26 extend in a direction (X direction) intersecting the stacking direction. The positive electrode terminal 24 and the negative electrode terminal 26 can be used to charge and discharge the power storage device 10.

The conductor 14 can also function as a heat sink for releasing the heat generated in the power storage module 12. By allowing a refrigerant such as air to pass through the plurality of through holes 14a provided inside the conductor 14, the heat generated in the power storage module 12 can be efficiently released to the outside. Each through hole 14a extends in a direction (Y direction) intersecting the stacking direction, for example.

The power storage device 10 may include a restraint member 15 that restrains the alternately stacked power storage modules 12 and the conductor 14 in the stacking direction. The restraint member 15 includes a pair of restraint plates 16 and 17 and a connecting member (bolt 18 and nut 20) for connecting the restraint plates 16 and 17 to each other. An insulating film 22 such as a resin film is arranged between the restraint plates 16 and 17 and the conductor 14. Each of the restraint plates 16 and 17 is made of, for example, a metal such as iron.

When viewed from the stacking direction, the restraint plates 16 and 17 and the insulating film 22 have, for example, a rectangular shape. The insulating film 22 is larger than the conductor 14, and the restraint plates 16 and 17 are larger than the power storage module 12. When viewed from the stacking direction, an insertion hole 16a through which the shaft portion of the bolt 18 is inserted is provided at a position outside the power storage module 12 at the edge portion of the restraint plate 16. Similarly, when viewed from the stacking direction, an insertion hole 17a through which the shaft portion of the bolt 18 is inserted is provided at a position outside the power storage module 12 at the edge portion of the restraint plate 17. When the restraint plates 16 and 17 have a rectangular shape when viewed from the stacking direction, the insertion holes 16a and the insertion holes 17a are located at the corners of the restraint plates 16 and 17.

One restraint plate 16 is abutted against the conductor 14 connected to the negative electrode terminal 26 via the insulating film 22, and the other restraint plate 17 has the insulating film 22 attached to the conductor 14 connected to the positive electrode terminal 24. It is struck through. For example, the bolt 18 is passed through the insertion hole 16a from one restraint plate 16 side toward the other restraint plate 17, and a nut 20 is screwed into the tip of the bolt 18 protruding from the other restraint plate 17. ing. As a result, the insulating film 22, the conductor 14, and the power storage module 12 are sandwiched and unitized, and a restraining load is applied in the stacking direction.

As shown in FIG. 2, the power storage module 12 includes a laminate 30 having a bipolar electrode group 33 in which a plurality of bipolar electrodes 32 are laminated. When viewed from the stacking direction of the bipolar electrode group 33 (the Z direction, which is the same as the stacking direction of the power storage module 12 and the conductor 14), the laminated body 30 has, for example, a rectangular shape. A separator 40 is arranged between the bipolar electrodes 32 and 32 adjacent to each other. That is, the bipolar electrodes 32 of the bipolar electrode group 33 are laminated via the separator 40.

The bipolar electrode 32 includes an electrode plate 34, a positive electrode layer 36 provided on one surface of the electrode plate 34, and a negative electrode layer 38 provided on the other surface of the electrode plate 34. In the laminated body 30, the positive electrode layer 36 of one bipolar electrode 32 faces the negative electrode layer 38 of one of the bipolar electrodes 32 adjacent to each other in the stacking direction with the separator 40 interposed therebetween, and the negative electrode layer 38 of one bipolar electrode 32 is It faces the positive electrode layer 36 of the other bipolar electrode 32 that is adjacent to each other in the stacking direction with the separator 40 in between.

In the laminated body 30, terminal electrodes 35 having a positive electrode layer 36 or a negative electrode layer 38 provided only on one surface of the electrode plate 34 are arranged at both ends in the stacking direction. Specifically, in the stacking direction, a terminal electrode 35 (negative electrode side terminal electrode) having a negative electrode layer 38 arranged on the inner side surface is arranged at one end of the laminated body 30, and a positive electrode layer on the inner side surface at the other end. The terminal electrode 35 (positive electrode side terminal electrode) on which 36 is arranged is arranged. The negative electrode layer 38 of the negative electrode side terminal electrode faces the positive electrode layer 36 of the uppermost bipolar electrode 32 via the separator 40. The positive electrode layer 36 of the positive electrode side terminal electrode faces the negative electrode layer 38 of the lowermost bipolar electrode 32 via the separator 40. The electrode plates 34 of the terminal electrodes 35 are connected to adjacent conductors 14 (see FIG. 1).

In the laminated body 30, a frame-shaped first seal portion 52 that holds the peripheral edge portion 34a of the electrode plate 34 is joined to the peripheral edge portion 34a of the electrode plate 34. The first sealing portion 52 is provided in the laminated body 30 from one surface of the electrode plate 34 of the bipolar electrode 32 (the surface on which the positive electrode layer 36 is formed) to the end surface of the electrode plate 34 on the peripheral edge portion 34a. When viewed from the stacking direction, each of the first seal portions 52 is provided over the entire circumference of the peripheral edge portion 34a of each electrode plate 34. The first seal portions 52, 52 adjacent to each other are arranged in contact with each other in the stacking direction. The thickness D1 of the first seal portion 52 is, for example, 100 to 500 μm. In this embodiment, the "thickness" means the length (dimensions) in the stacking direction (Z direction). By arranging the first seal portion 52 in contact with the laminated body 30, the electrode plates 34 are laminated at regular intervals (for example, 0.25 mm) according to the thickness D1 of the first seal portion 52. It has become.

The first sealing portion 52 is welded on a surface extending outside the other surface (the surface on which the negative electrode layer 38 is formed) of the electrode plate 34 of each bipolar electrode 32. As a result, the peripheral edge portion 34a of the electrode plate 34 of each bipolar electrode 32 is buried and held in the first seal portion 52. Similar to the peripheral edge portion 34a of the electrode plate 34 of each bipolar electrode 32, the peripheral edge portions 34a of the electrode plates 34 arranged at both ends of the laminated body 30 are also held in a state of being buried in the first seal portion 52. As a result, an internal space V that is airtightly partitioned by the electrode plates 34, 34 and the first seal portion 52 is formed between the electrode plates 34, 34 that are adjacent to each other in the stacking direction. The internal space V contains an electrolytic solution (not shown) composed of an alkaline solution such as an aqueous potassium hydroxide solution.

The power storage module 12 includes conductive plates 37 arranged via conductive members 39 at both ends of the laminated body 30 in the stacking direction. The conductive plate 37 has the same dimensions and shape as the electrode plate 34 when viewed from the stacking direction and the direction intersecting the stacking directions. It should be noted that the same in the present specification includes not only exactly the same dimensions and shapes, but also substantially the same dimensions and shapes with slight differences. Here, comparing the electrode plate 34 and the conductive plate 37, the electrode plate 34 is provided with the positive electrode layer 36 or the negative electrode layer 38 on at least one of one surface and the other surface, whereas the conductive plate 37 is provided with the positive electrode layer 36 or the negative electrode layer 38. The difference is that neither the positive electrode layer 36 nor the negative electrode layer 38 is provided on either one surface or the other surface. That is, the conductive plate 37 is a member that is not coated with the active material that constitutes the positive electrode layer 36 or the negative electrode layer 38. The conductive plate 37 electrically connects the conductors 14 (see FIG. 1) adjacent to each other at both ends of the power storage module 12 and the laminated body 30. A frame-shaped third seal portion 56 that holds the peripheral edge portion 37a of the conductive plate 37 is joined to the peripheral edge portion 37a of the conductive plate 37.

The third seal portion 56 is provided from one surface of the conductive plate 37 to the end surface of the conductive plate 37 on the peripheral edge portion 37a. When viewed from the stacking direction, the third seal portion 56 is provided over the entire circumference of the peripheral edge portion 37a of the conductive plate 37. The third seal portion 56 has the same shape and dimensions as the first seal portion 52 when viewed from the stacking direction. The third seal portion 56 is arranged in contact with the adjacent first seal portions 52 in the stacking direction. The thickness D2 of the third seal portion 56 is, for example, 0.5 to 1.0 times the thickness D1 of the first seal portion 52. The thickness D2 of the third seal portion 56 may be the same as, for example, the thickness D1 of the first seal portion 52, or may be smaller than the thickness D1 of the first seal portion 52.

The conductive member 39 is interposed between the laminated body 30 and the conductive plate 37. The conductive member 39 is arranged in contact with the electrode plates 34 and the conductive plates 37 arranged at both ends of the laminated body 30. As shown in FIG. 3, the area of the conductive member 39 is smaller than the area surrounded by the first seal portion 52 when viewed from the stacking direction. The conductive member 39 is arranged inside the inner side surface 52a of the first seal portion 52 when viewed from the stacking direction.

Further, as shown in FIG. 2, the power storage module 12 includes a second seal portion 54 that integrally holds the laminate 30 and the third seal portion 56 on the side surface 30a of the laminate 30 extending in the stacking direction. .. In other words, the electrode plate 34 is held by the second seal portion 54 via the first seal portion 52, and the conductive plate 37 is held by the second seal portion 54 via the third seal portion 56. The second seal portion 54 is configured to surround the laminate 30, the conductive plate 37, and the conductive member 39. The outer surface 54b of the second seal portion 54 has, for example, a rectangular shape when viewed from the stacking direction. In this case, the outer surface 54b is composed of four rectangular surfaces.

The second seal portion 54 is a tubular portion extending over the entire length of the laminated body 30 in the stacking direction. The second seal portion 54 covers the outer surface 52b of the first seal portion 52 and the outer surface 56b of the third seal portion 56 on the inner side surface 54a extending in the stacking direction of the bipolar electrode 32. The second seal portion 54 is integrally formed with the first seal portion 52 and the third seal portion 56 by injection molding. The first seal portions 52 and 52 adjacent to each other are integrally joined by the second seal portion 54. Further, the first seal portion 52 and the third seal portion 56 adjacent to each other are integrally joined by the second seal portion 54.

The electrode plate 34 is, for example, a rectangular metal leaf made of nickel. The peripheral edge portion 34a of the electrode plate 34 is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated, and the uncoated region is a region buried and held in the first seal portion 52. ing. Examples of the positive electrode active material constituting the positive electrode layer 36 include nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode layer 38 include a hydrogen storage alloy. The formation region of the negative electrode layer 38 on the second surface 34t of the electrode plate 34 is slightly larger than the formation region of the positive electrode layer 36 on the first surface 34s of the electrode plate 34. The electrode plate 34 may be formed of Ni-plated iron foil or a conductive resin.

The conductive plate 37 is made of the same material as the electrode plate 34. That is, the conductive plate 37 may be a rectangular metal foil made of nickel, or may be formed of a Ni-plated iron foil or a conductive resin. However, the conductive plate 37 may be made of a material different from that of the electrode plate 34. Neither the positive electrode active material nor the negative electrode active material is coated on the conductive plate 37. The conductive member 39 may be, for example, a rectangular metal foil made of nickel, a nickel plate, or a steel plate plated with nickel.

The separator 40 is formed in a sheet shape, for example. Examples of the material forming the separator 40 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, and a non-woven fabric. Further, the separator 40 may be reinforced with a vinylidene fluoride resin compound.

The first seal portion 52, the second seal portion 54, and the third seal portion 56 are formed of, for example, an insulating resin. Examples of resin materials constituting each of the first seal portion 52, the second seal portion 54, and the third seal portion 56 include polypropylene (PP), polyphenylene sulfide (PPS), and modified polyphenylene ether (modified PPE). Is included.

As shown in FIG. 2, the power storage module 12 described above includes conductive plates 37 arranged at both ends of the laminated body 30 in the stacking direction. The second seal portion 54 surrounds the conductive plate 37 and the laminated body 30 together, and integrally holds the conductive plate 37 and the first seal portion 52. Therefore, when such a second seal portion 54 is formed by, for example, injection molding, the conductive plate 37 presses the first seal portion 52 that holds the peripheral edge portion 34a of the electrode plate 34 arranged on the outermost layer. However, the impact of the flow of the resin on the first seal portion 52 is alleviated by the conductive plate 37, so that the first seal portion 52 is prevented from being rolled up. Therefore, the first seal portions 52 can be sufficiently connected to each other by the second seal portion 54. As described above, it is possible to suppress a decrease in the airtightness of the power storage module.

Further, in the power storage module 12, a frame-shaped third seal portion 56 is joined to the peripheral edge portion 37a of the conductive plate 37, and the conductive plate 37 is connected to the second seal portion 54 via the third seal portion 56. It is joined to. With this configuration, since the third seal portion 56 is arranged on the end side of the first seal portion 52 arranged on the end side of the laminate 30, other portions at both ends of the laminate 30 in the stacking direction. It is possible to form a portion having a higher rigidity than that. Therefore, during injection molding of the second seal portion 54, the first seal portion 52 arranged on the end side of the laminated body 30 is further suppressed from being rolled up. Further, even if the third seal portion 56 arranged on the end side of the laminated body 30 is rolled up during injection molding of the second seal portion 54, the first seal portion 52 and the second seal portion 54 The airtightness of the power storage module 12 is sufficiently ensured.

Further, the power storage module 12 further includes a conductive member 39 interposed between the laminated body 30 and the conductive plate 37, and the conductive member 39 is seen from the inner side surface 52a of the first seal portion 52 when viewed from the stacking direction. Is also placed inside. The larger the thickness D2 of the conductive plates 37 arranged at both ends of the laminated body 30, the more effective it is to suppress the curling up of the first seal portion 52. In this configuration, by interposing the conductive member 39 between the laminated body 30 and the conductive plate 37, the same effect as increasing the thickness D2 of the conductive plate 37 can be obtained. Further, in this configuration, the conductive member 39 having a volume smaller than the amount of increase in the volume of the conductive plate 37 when the thickness D2 of the conductive plate 37 is increased is interposed. Thereby, when the material of the conductive member 39 is the same as the material of the conductive plate 37, the cost can be reduced. Further, as the material of the conductive member 39, a material cheaper than the material of the conductive plate 37 can be used, and in that case, the cost can be further reduced.

In the power storage module 12 described above, the conductive plate 37 and the electrode plate 34 are made of the same material and have the same dimensions and shapes when viewed from the stacking direction and the direction intersecting the stacking direction. With this configuration, the electrode plate 34 of the bipolar electrode 32 can also be used as the conductive plate 37, so that it is possible to save the trouble of preparing a separate member as the conductive plate 37.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

In the above embodiment, the configuration in which the conductive member 39 is interposed between the laminated body 30 and the conductive plate 37 has been described as an example, but the conductive member 39 is interposed between the laminated body 30 and the conductive plate 37. Does not have to be intervened. For example, the electrical connection between the laminate 30 and the conductive plate 37 may be ensured by arranging the laminate 30 and the conductive plate 37 so as to be in direct contact with each other. In the power storage module 12A shown in FIG. 4, three conductive plates 37 are continuously laminated in the stacking direction on one end side of the laminated body 30. Of the three conductive plates 37, the conductive plate 37 arranged closest to the laminated body 30 comes into contact with the laminated body 30, and an electrical connection between the laminated body 30 and the conductive plate 37 is secured. As described above, two or more conductive plates 37 may be continuously laminated in the stacking direction on at least one of the one end side and the other end side of the laminated body 30 in the stacking direction. The thickness can be adjusted to an arbitrary value by continuously laminating two or more conductive plates 37.

Further, in the power storage module 12B shown in FIG. 5, two conductive plates 37 are continuously laminated in the stacking direction on one end side of the laminated body 30, and between the laminated body 30 and the conductive plate 37. A conductive member 39 is interposed. In this way, a configuration in which the conductive member 39 is interposed between the laminated body 30 and the conductive plate 37 and a configuration in which two or more conductive plates 37 are continuously laminated may be combined. Alternatively, at least one of the one end side and the other end side of the laminate 30 in the stacking direction, only one conductive plate 37 having an arbitrary thickness may be arranged so as to come into contact with the laminate 30.

Further, in the above-described embodiment and modified example, a frame-shaped third seal portion 56 for holding the peripheral edge portion 37a of the conductive plate 37 is joined to the peripheral edge portion 37a of the conductive plate 37, and the conductive plate 37 is formed with the conductive plate 37. Although the configuration in which the conductive plate is joined to the second seal portion 54 via the third seal portion 56 has been illustrated and described, as shown in FIG. 6, the conductive plate has a second seal portion 56 without passing through the third seal portion 56. It may be a conductive plate 37C joined to the seal portion 54.

The power storage module 12C shown in FIG. 6 includes a conductive plate 37C in which three conductive plates 37C are continuously laminated in the stacking direction at at least one of one end and the other end of the laminated body 30 in the stacking direction. Of the three conductive plates 37C, the conductive plate 37 arranged closest to the laminated body 30 comes into contact with the laminated body 30, and an electrical connection between the laminated body 30 and the conductive plate 37C is secured. The conductive plate 37C has a rectangular shape larger than that of the electrode plate 34 when viewed from the stacking direction. When viewed from the stacking direction, the area of the conductive plate 37C is larger than the area surrounded by the outer surface 52b of the first sealing portion 52. The outer surface 37b of the conductive plate 37C is covered with the second seal portion 54, and the conductive plate 37C is joined to the adjacent first seal portion 52 by the second seal portion 54. The conductive plate 37C may be made of the same material as the electrode plate 34, similarly to the conductive plate 37.

Further, in the above-described embodiment or modified example, the power storage device 10 including the power storage module has been described with reference to an example of a nickel-metal hydride secondary battery, but a lithium ion secondary battery may also be used. In this case, the positive electrode active material is, for example, a composite oxide, metallic lithium, sulfur or the like. The negative electrode active material is, for example, graphite, highly oriented graphite, mesocarbon microbeads, carbon such as hard carbon and soft carbon, alkali metals such as lithium and sodium, metal compounds, SiOx (0.5 ≦ x ≦ 1.5). Such as metal oxides, carbon with added boron, and the like.

12, 12A, 12B, 12C ... Energy storage module, 30 ... Laminated body, 30a ... Side surface, 32 ... Bipolar electrode, 33 ... Bipolar electrode group, 34 ... Electrode plate, 34a ... Peripheral portion, 36 ... Positive electrode layer, 37, 37C ... Conductive plate, 37a ... peripheral edge, 38 ... negative electrode layer, 39 ... conductive member, 40 ... separator, 52 ... first seal, 52a ... inner surface, 52b ... outer surface, 54 ... second seal, 56 ... 3 Seals, D1, D2 ... Thickness.

Claims (5)

A bipolar electrode including an electrode plate, a positive electrode layer provided on one surface of the electrode plate, and a negative electrode layer provided on the other surface of the electrode plate, and a positive electrode provided on the electrode plate and one surface of the electrode plate. A power storage module including a positive electrode side terminal electrode including a layer and a negative electrode side terminal electrode including the electrode plate and a negative electrode side provided on one surface of the electrode plate.
The bipolar electrode group in which the bipolar electrodes are laminated via a separator, the positive electrode side terminal electrode arranged at one end of the bipolar electrode group in the stacking direction, and the other end of the bipolar electrode group in the stacking direction are arranged. A frame-shaped first seal portion is joined to the peripheral portions of the electrode plates of the bipolar electrode, the positive electrode side terminal electrode, and the negative electrode side terminal electrode. Laminated body and
A pair of conductive plates arranged at both ends of the laminated body in the laminating direction and holding down the first sealing portion joined to the peripheral edge portion of the electrode plate arranged on the outermost layer of the laminated body.
A second seal that is arranged so as to cover the side surfaces of the laminate extending in the lamination direction and each peripheral edge of the pair of conductive plates, and integrally joins the first seal portion and the conductive plates. A power storage module equipped with a unit. A frame-shaped third seal portion is joined to the peripheral edge portion of the conductive plate.
The power storage module according to claim 1, wherein the conductive plate is joined to the second seal portion via the third seal portion. Further provided with a conductive member interposed between the laminated body and the conductive plate,
The power storage module according to claim 1 or 2, wherein the conductive member is arranged inside the inner side surface of the first seal portion when viewed from the stacking direction. The conductive plate and the electrode plate are made of the same material, and have the same dimensions and shape when viewed from the stacking direction and when viewed from a direction intersecting the stacking direction. The power storage module according to any one of claims 1 to 3. The present invention according to any one of claims 1 to 4, wherein two or more conductive plates are continuously laminated in the stacking direction at least one of the one end side and the other end side of the laminated body in the stacking direction. The power storage module described.

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