JP7284614B2 - Cell assembly and power storage element module - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cell assembly having a plurality of cells and a power storage element module including the cell assembly.

For example, as disclosed in Patent Document 1, a power storage element module including a plurality of cells is known. Each cell has a flat plate-like outer contour. In the electric storage element module, flat-shaped cells are stacked at high density. By electrically connecting a plurality of cells in series or in parallel, the storage element module has desired voltage and capacity.

It has been confirmed that the temperature of each cell rises during charging and discharging, and the tab of the cell becomes a heat source at this time. The tab is electrically connected to the electrode plate and functions as a connection terminal with other cells. Heat distribution tends to be non-uniform in a flat-shaped cell, and the temperature may rise locally near the tab.

On the other hand, the life of cells represented by lithium ion secondary batteries is affected by temperature. Degradation progresses in the part of the cell where the temperature is raised. If local deterioration occurs inside the cell, an imbalance occurs in the chemical reaction inside the cell, accelerating the deterioration of the entire cell.

JP 2017-5027 A

SUMMARY OF THE INVENTION An object of the present invention is to suppress local temperature rise in the vicinity of the tab of a cell.

The cell assembly according to the present invention is
comprising a first cell and a second cell;
The first cell and the second cell are respectively composed of an electrode body including a plurality of electrode plates, an exterior body containing the electrode body, and an exterior body connected to the electrode body and extending to the outside of the exterior body. has tabs and
The tab of the first cell is in contact with the tab of the second cell at a connecting portion located between a base end connected to the armor and a tip farthest away from the armor. are electrically connected.

In the cell assembly according to the present invention, the tab of the second cell is connected to the second cell at a connection portion located between a base end connected to the armor and a tip farthest away from the armor. It may be in contact with and electrically connected to the tab of one cell.

In the cell assembly according to the present invention, the tab of the second cell may be spaced apart from the tab of the first cell at a portion closer to the distal end than the connecting portion.

In the cell assembly according to the present invention, the tab of the first cell and the tab of the second cell gradually become You may make it space apart.

In the cell assembly according to the present invention, the tab of the first cell may be provided with a slit in a portion closer to the tip than the connecting portion.

In the cell assembly according to the present invention, the slit may extend from the tip portion toward the connecting portion.

In the cell assembly according to the present invention, the slit may extend from the side edge of the tab in a direction non-parallel to the direction connecting the tip portion and the connection portion.

In the cell assembly according to the present invention, the slits may include a plurality of slits extending from opposite side edges alternately from the connection portion toward the tip portion.

In the cell assembly according to the present invention, portions of the tab located on both sides of the slit may be separated from each other through the slit.

The cell assembly according to the present invention may further include a heat radiating member in contact with a portion of the tab of the first cell that is closer to the tip than the connecting portion.

In the cell assembly according to the present invention, the heat dissipation member may include heat dissipation fins.

In the cell assembly according to the present invention, the heat dissipation member may be made of a material having higher thermal conductivity than the tab.

In the cell assembly according to the present invention, the tab of the first cell may be bent in a region closer to the tip than the connecting portion.

In the cell assembly according to the present invention, the tab of the first cell may be bent multiple times so as to alternately reverse from the connection portion toward the tip portion.

In the cell assembly according to the present invention, the first cell and the second cell may be laminated together.

A power storage element module according to the present invention includes any of the above-described cell assemblies according to the present invention.

According to the present invention, it is possible to effectively suppress a local temperature rise in the vicinity of the tab of the cell.

FIG. 1 is a diagram for explaining an embodiment of the present invention, and is a side view schematically showing the configuration of a power storage element module and a cell assembly. FIG. 2 is a perspective view showing a cell that can be included in the energy storage element module and cell assembly of FIG. 1. FIG. FIG. 3 is a perspective view showing the inside of the cell of FIG. 2 with the exterior body, the insulator, etc. removed. FIG. 4 is a partial vertical cross-sectional view taken along line IV-IV of FIG. 2 and showing cross-sections along both the first direction and the second direction of the cell of FIG. 5 is a perspective view illustrating tabs of first and second cells included in the cell assembly of FIG. 1. FIG. FIG. 6 is a view corresponding to FIG. 5 and a perspective view for explaining another example of the tabs of the first and second cells. FIG. 7 is a view corresponding to FIG. 5 and a perspective view for explaining still another example of the tabs of the first and second cells. FIG. 8 is a view corresponding to FIG. 5 and a perspective view for explaining still another example of the tabs of the first and second cells. FIG. 9 is a view corresponding to FIG. 5 and a perspective view for explaining still another example of the tabs of the first and second cells. FIG. 10 is a diagram corresponding to FIG. 1 and for explaining a modified example of the cell assembly and the cells.

An embodiment of the present invention will now be described with reference to specific examples shown in the drawings. In addition, in the drawings attached to this specification, for the convenience of illustration and ease of understanding, the scale and the ratio of vertical and horizontal dimensions are appropriately changed and exaggerated from those of the real thing.

1 to 10 are diagrams for explaining an embodiment according to the present invention. 1 is a schematic diagram showing the main configuration of the storage element module, FIG. 2 is a perspective view showing a cell included in the storage element module 10, and FIG. 3 is a perspective view showing the inside of the cell in FIG. 4 is a partial longitudinal cross-sectional view of the cell of FIG. 2; FIG.

The power storage element module 10 is typically a secondary battery module that can be charged and discharged, and can be used as an emergency power source, a household power source, an on-vehicle power source, and the like. As shown in FIG. 1 , the power storage element module 10 includes many cells 20 . A cell 20 is a minimum unit treated as a power storage element. The cell 20 can be of various types, such as a lithium ion secondary battery. A plurality of cells 20 included in one power storage element module 10 may have the same configuration, or may have different configurations.

In particular, in one embodiment described below, by devising the configuration of the tabs 30 used for electrical connection with other cells 20, local temperature rise in the cells 20 can be effectively avoided. can. As a result, local deterioration of the cell 20 can be effectively prevented, and the life of the cell 20 can be extended.

First, the cell 20 will be described with reference to FIGS. 2 to 4. FIG. A specific example in which the cell 20 is a lithium ion battery will be described below. However, the present embodiment can be applied to various types of cells without being limited to lithium ion batteries.

As shown in FIGS. 2 and 3, the cell 20 includes an electrode body 21 including a plurality of electrode plates 22, an exterior body 25 housing the electrode body 21, and the electrode plates 22 of the electrode body 21 electrically connected. and a tab 30 extending to the outside of the exterior body 25 . Cell 20 has a pair of tabs 30 . A pair of tabs 30 function as a positive terminal or a negative terminal, respectively. Tab 30 is formed of a metal plate. The cell 20 has a flat shape as a whole.

As shown in FIG. 3, the electrode body 21 has a plurality of positive plates 22A and a plurality of negative plates 22B. The positive electrode plate 22A and the negative electrode plate 22B are included in one outer package 25, for example, 10 or more each, or 15 or more each, or 20 or more each. The positive electrode plates 22A and the negative electrode plates 22B are alternately arranged along the first direction DA, which is the stacking direction. The cell 20 and the electrode body 21 have a flat shape as a whole, are thin in the first direction DA, and extend in a second direction DB and a third direction D3 orthogonal to the first direction DA.

In order to clarify the directional relationship among the drawings, the first direction DA, the second direction DB, the third direction D3, and the later-described stacking direction DL are shown as common directions among the drawings.

In the illustrated non-limiting example, the positive plate 22A and the negative plate 22B have rectangular contours. The positive electrode plate 22A and the negative electrode plate 22B have a longitudinal direction in a second direction DB orthogonal to the first direction DA and a lateral direction in a third direction DC orthogonal to both the first direction DA and the second direction DB. have. As shown in FIG. 3, the positive electrode plate 22A and the negative electrode plate 22B are arranged to be shifted in the second direction DB. More specifically, the plurality of positive plates 22A are arranged closer to one side (lower left side in FIG. 3) in the second direction DB, and the plurality of negative plates 22B are arranged closer to the other side in the second direction DB (see FIG. 3). (upper right side of )). The positive electrode plate 22A and the negative electrode plate 22B overlap with the first direction DA at the center in the second direction DB.

In addition to the electrode plate 22 , the electrode body 21 further has an insulator 23 as shown in FIG. 4 . The insulator 23 is arranged between two positive electrode plates 22A and negative electrode plates 22B adjacent to each other in the first direction DA. The insulator 23 prevents a short circuit between the positive electrode plate 22A and the negative electrode plate 22B. Note that the illustration of the insulator 23 is omitted in FIG.

The exterior body 25 is formed by stacking two exterior materials 26 and 27 and bonding (welding) the peripheral edges of the exterior materials 26 and 27 . In other words, a bonding area is provided on the periphery of the exterior body 25 by bonding the two exterior materials 26 and 27 together. The tab 30 passes between the two exterior members 26 and 27 and extends from the interior of the exterior body 25 to the exterior.

In the illustrated example, the first exterior member 26 is formed as a plate-like member. On the other hand, the second exterior member 27 is formed in a cup shape. The second exterior member 27 has a cup-shaped swelling portion 27a and a collar portion 27b connected to the swelling portion 27a. The flange portion 27b is connected to the peripheral edge of the bulging portion 27a and surrounds the bulging portion 27a. The flange portion 27b is joined (for example, welded) to the first exterior material 26 so as to seal the accommodation space between the first exterior material 26 and the second exterior material 27 . The bulging portion 27a is manufactured by drawing, for example.

Tabs 30 function as terminals in cell 20 . One tab 30 is provided corresponding to the positive electrode plate 22A of the electrode body 21 . As shown in FIG. 4 , this one tab 30 is electrically connected to all the positive plates 22A included in the electrode body 21 . The other tab 30 is provided corresponding to the negative electrode plate 22B of the electrode assembly 21 . The other tab 30 is electrically connected to all the positive plates 22A included in the electrode body 21. As shown in FIG. The tab 30 is a plate-like member that can be formed using aluminum, nickel, nickel-plated copper, or the like. In the illustrated example, the tab 30 is pulled out of the exterior body 25 from the electrode body 21 along the second direction DB.

The space between the outer package 25 and the tab 30 is sealed in the region where the tab 30 extends. Specifically, as shown in FIG. 4 , a sealing material 29 is provided between the tab 30 and the exterior body 25 . The sealing material 29 seals between the tab 30 and the exterior body 25 to seal the accommodation space of the exterior body 25 . Moreover, the sealing material 29 has adhesiveness and joins the tab 30 and the exterior body 25 . Electrolyte solution is enclosed together with the electrode body 21 in the hermetically sealed exterior body 25 .

As described above, the power storage element module 10 is configured by electrically connecting a large number of cells 20 configured as described above in series or in parallel. By appropriately setting the number and connection of the cells 20 in series and parallel, the output from one power storage element module 10 can be a desired voltage and a desired capacity. As an example, the storage element module 10 shown in FIG. 1 includes 12 cells 20 .

In the example shown in FIG. 1, six parallel-connected cells 20 are connected in series. In the example shown in FIG. 1, two cells 20 connected in parallel constitute the cell assembly 15 . Therefore, in the example shown in FIG. 1, six cell assemblies 15 are connected in series in one storage element module 10 .

The first cells 20A and the second cells 20B included in each cell assembly 15 are arranged in the stacking direction DL such that the first directions DA are substantially aligned with each other. Also, the first cell 20A and the second cell 20B included in each cell assembly 15 are substantially aligned in the second direction DB and substantially aligned in the third direction DC. , are stacked. However, the first cell 20A and the second cell 20B are opposite in the stacking direction DL. The first cells 20A and the second cells 20B included in each cell assembly 15 are stacked such that the first exterior materials 26 face each other. In each cell assembly 15, the bulging portion 27a of the second exterior material 27 of the first cell 20A protrudes away from the second cell 20B, and the bulging portion 27a of the second exterior material 27 of the second cell 20B protrudes away from the first cell 20A. The tabs 30 forming positive terminals of the first cell 20A and the second cell 20B face each other in the stacking direction DL and are electrically connected to each other. Further, the tabs 30 forming the negative terminals of the first cell 20A and the second cell 20B face each other in the stacking direction DL and are electrically connected to each other.

In addition, the plurality of cell assemblies 15 included in one storage element module 10 and connected in series are stacked such that the first direction DA of the cells 20 constituting each cell assembly 15 is substantially aligned. It is arranged in the direction DL. Two cell assemblies 15 connected in series are arranged adjacent to each other in the stacking direction DL. In addition, the plurality of cell assemblies 15 included in the storage element module 10 are arranged so that the second direction DA of the cells 20 constituting each cell assembly 15 are substantially aligned, and the cells constituting each cell assembly 15 20 are arranged so as to substantially align the third direction DC. However, the two cell assemblies 15 connected in series with each other are arranged such that the cells 20 forming each cell assembly 15 face in opposite directions in the second direction DA. The two cell assemblies 15 that are connected in series with each other are arranged such that the tabs 30 forming terminals of different polarities face each other in the stacking direction DL. The tabs 30 forming terminals of different polarities are electrically connected, for example, via the connecting wiring 12 or the like.

As described above, all the cells 20 included in one power storage element module 10 are stacked such that the first direction DA is aligned with the stacking direction DL. Therefore, in the electric storage element module 10, a large number of cells 20 can be arranged at high density, and the energy density can be improved. In particular, the illustrated cell 20 has a plane-symmetrical outer shape with respect to a plane located at the center in the second direction DB and orthogonal to the second direction DB. Similarly, the illustrated cell 20 has a plane-symmetrical outer shape with respect to a plane positioned at the center in the third direction DC and orthogonal to the third direction DC. Therefore, it is possible to arrange a large number of cells 20 at a higher density.

By the way, it is generally confirmed that the temperature of each cell 20 rises during charging and discharging, and at this time, the tab 30 of the cell 20 becomes a heat source. Also, the laminate type cell 20 having the exterior body 25 formed by laminating the exterior materials 26 and 27 is normally formed in a flat shape, in other words, in a flat plate shape. Heat distribution tends to be non-uniform in such a flat-shaped cell 20 . The tab 30 is normally electrically connected to a large number of electrode plates 22 and also electrically connected to the tabs 30 of other cells 20. easier to do. In the first place, the electric storage element module 10 includes a large number of flat-shaped cells 20 that are densely stacked. As a result, heat tends to be trapped in the central portion of the power storage element module 10, resulting in insufficient heat dissipation.

On the other hand, the life of the cell 20 is greatly affected by temperature, and is shortened by being exposed to high temperatures for a long period of time. Further, when the cell 20 is locally heated, the heated portion locally deteriorates. Furthermore, if local deterioration occurs inside the cell 20, an imbalance occurs in the chemical reaction inside the cell 20, resulting in rapid deterioration of the entire cell.

On the other hand, in the present embodiment, as shown in FIG. 5, the tab 30 of the first cell 20A is located between the base end portion 31 connected to the outer package 25 and the distal end portion 32 farthest from the outer package 25. It is in contact with the tab 30 of the second cell 20B at the connecting portion 33 located. At this connecting portion 33, the tab 30 of the first cell 20A is electrically connected to the tab 30 of the second cell 20B. The tab 30 of the first cell 20A is fixed to the tab 30 of the second cell 20B at the connection portion 33 by, for example, ultrasonic welding or laser welding, and electrical connection is ensured.

In such a configuration, current flows through the region between the proximal end 31 and the connecting portion 33 of the tab 30 between the first cell 20A and the second cell 20B. On the other hand, the current does not flow through the area of the tab 30 that is closer to the distal end portion 32 than the connecting portion 33 . This region is an unnecessary region for the cell assembly 15 and the storage element module 10 to function as a storage element such as a secondary battery. Therefore, the region of the tab 30 closer to the distal end portion 32 than the connecting portion 33 does not become a heat source.

On the other hand, in the present embodiment, the region 35 of the tab 30 that is closer to the distal end portion 32 than the connecting portion 33 is used as a heat radiating portion. Tab 30 is generally formed in a plate shape. Therefore, the surface area to volume ratio of the heat dissipation region 35 is very high. Therefore, heat can be dissipated from the heat dissipating region 35 with high efficiency. Thus, according to the present embodiment, the tab 30 functions as a part that secures electrical connection and has the heat dissipation region 35 for heat dissipation. Therefore, the heat in the vicinity of the tab 30 which is likely to be locally heated can be efficiently radiated from the heat radiating region 35 . Also, the heat trapped in the center of the storage element module 10 can be absorbed by the tab 30 and further radiated from the heat radiation area 35 of the tab 30 . In this way, it is possible to effectively suppress the temperature rise of the cell 20 , especially the local temperature rise near the tab 30 . As a result, deterioration of the cell 20, especially local early deterioration near the tab 30 can be effectively avoided, and the service life of the cell 20 can be extended.

In the example shown in FIG. 5, like the tab 30 of the first cell 20A, the tab 30 of the second cell 20B also has a proximal end portion 31 connected to the armor 25 and a distal end farthest from the armor 25. It is electrically connected to the tab 30 of the first cell 20A in contact with the connection portion 33 located between the portion 32 and the portion 32 . According to such a specific example, the heat dissipation region 35 of the tab 30 of the second cell 20B, which is closer to the tip portion 32 than the connection portion 33, can also function as a heat dissipation portion. Therefore, it is possible to more effectively suppress the temperature rise of the cell 20, especially the local temperature rise near the tab.

Furthermore, in the example shown in FIG. 5, the tab 30 of the second cell 20B is separated from the tab 30 of the first cell 20A in the heat dissipation region 35 which is closer to the tip 32 than the connecting portion 33 is. That is, the heat dissipation region 35 of the tab 30 of the first cell 20A and the heat dissipation region 35 of the tab 30 of the second cell 20B are separated from each other. According to such a specific example, the surface area of the heat dissipation region 35 of the tab 30 included in the cell assembly 15 can be efficiently increased. Therefore, the temperature rise of the cell 20, especially the local temperature rise near the tab 30 can be suppressed more effectively.

Furthermore, in the example shown in FIG. 5, the tab 30 of the first cell 20A and the tab 30 of the second cell 20B are in contact with each other and are electrically connected to each other. Gradually separate. More specifically, as shown in FIGS. 1 and 5, the spacing along the stacking direction DL between the tabs 30 of the first cell 20A and the tabs 30 of the second cell 20B is It spreads as it separates to the side. According to such specifics, the heat dissipation at the tip end portion 32 side of the heat dissipation region 35 is promoted. As a result, the transfer of heat toward the distal end portion 32 of the tab 30 is promoted, and accordingly, the heat of the cell 20 can be absorbed by the tab 30 and efficiently dissipated from the heat dissipation region 35 of the tab 30. . Therefore, heat can be more efficiently dissipated from the heat dissipating region 35 .

As an example different from the example shown in FIG. 5, the tab 30 of the first cell 20A shown in FIGS. is provided. By providing the slits 36 in the heat dissipation region 35, the surface area of the heat dissipation region 35 can be increased. For example, by separating the portions of the tab 30 located on both sides of the slit 36 from each other through the slit 36, the surface area of the heat radiation area 35 can be greatly expanded and heat radiation can be promoted. As a result, it is possible to more effectively suppress the temperature rise of the cell, especially the local temperature rise in the vicinity of the tab.

In the example shown in FIG. 6, the slit 36 extends from the tip portion 32 toward the connecting portion 33 . In particular, slit 36 extends along the length of tab 30 between tip 32 and connecting portion 33 . Here, the longitudinal direction of the tab 30 is the direction connecting the proximal end portion 31 and the distal end portion 32 . According to such a specific example, heat can be efficiently dissipated while disposing the heat dissipating region 35 of the tab 30 in a limited space. For example, the heat dissipation efficiency can be effectively improved by shifting the adjacent portions of the heat dissipation region 35 via the slits 36 in the stacking direction DL while suppressing an increase in size along the second direction DB. can. It is also possible to separate the portions of the tabs 30 located on both sides of the slit 36 in the third direction DC of each cell 20 via the slit 36. At this time, the cells 20 are brought closer together in the stacking direction DL. Heat dissipation can be promoted while arranging.

Moreover, in the example shown in FIG. 7, the slit 36 extends from the side edge of the tab 30 in a direction non-parallel to the direction connecting the tip portion 32 and the connecting portion 33 . According to such a specific example, it is possible to efficiently dissipate heat while arranging the heat dissipating region 35 in a limited space. For example, it is possible to increase the surface area of the heat dissipation region 35 of the tab 30 while effectively preventing an increase in size in any one of the stacking direction DL, the second direction DB, and the third direction DC. In particular, in the example shown in FIG. 7, the slits 36 include a plurality of slits 36 extending from the connecting portion 33 toward the distal end portion 32 from alternate side edges. According to such an example, it is possible to more efficiently arrange the large-area heat dissipation region 35 in a limited space.

As still another example, in the example shown in FIG. 8 , the tab 30 of the first cell 20A may be curved or bent in the heat dissipation region 35 closer to the tip 32 than the connecting portion 33 . According to such a specific example, heat can be efficiently dissipated while disposing the heat dissipating region 35 of the tab 30 in a limited space.

In the example shown in FIG. 8, the heat dissipation region 35 is bent multiple times from the connecting portion 33 toward the distal end portion 32 so as to be alternately reversed. In particular, the heat-radiating region 35 in FIG. 8 is bent alternately in opposite directions, and the bending axis is in a direction non-parallel to the longitudinal direction of the tab 30, particularly perpendicular to the longitudinal direction of the tab 30. It's becoming Such a heat dissipation area 35 has not only a large surface area but also a large heat capacity. Therefore, the heat dissipation region 35 of the tab 30 can effectively absorb heat from the inside of the cell 20 and efficiently dissipate the heat.

As still another example, as shown in FIG. 9, the cell assembly 15 or the cell 20 may further have a heat dissipation member 37. As shown in FIG. The heat radiating member 37 is in contact with the heat radiating region 35 located on the tip portion 32 side of the connecting portion 33 of the tab 30 of the first cell 20A, and is fixed to the heat radiating region 35 . Fixing of the heat radiating member 37 to the heat radiating region 35 may be performed by using a fastener such as a screw, or by ultrasonic bonding, adhesion using an adhesive, or the like. The heat dissipation region 35 is a member that promotes heat dissipation, and may be, for example, a heat dissipation fin as in the example shown in FIG. It may be a member. When fasteners such as screws are used, one heat dissipation member 37 may be fixed to both the heat dissipation region 35 of the tab 30 of the first cell 20A and the heat dissipation region 35 of the tab 30 of the second cell 20B. . By using the heat dissipation member 37 , heat absorption from the inside of the cell 20 to the tabs 30 and heat dissipation from the tabs 30 via the heat dissipation member 37 can be effectively promoted.

In the example shown in FIG. 9, the fins of the radiating fins extend in the width direction orthogonal to the longitudinal direction of the tab 30. As shown in FIG. However, the invention is not limited to this, and the fins of the radiation fins may extend in the longitudinal direction of the tab 30 . When the fins of the radiating fins extend in the longitudinal direction of the tab 30, heat transfer along the longitudinal direction of the tab 30 can be promoted, and as a result, efficient heat dissipation can be achieved.

In one embodiment described above, the cell assembly 15 has the first cells 20A and the second cells 20B. The first cell 20A and the second cell 20B are respectively composed of an electrode body 21 including a plurality of electrode plates 22, an exterior body 25 containing the electrode body 21, and connected to the electrode body 21 and extending to the outside of the exterior body 25. and a tab 30 that is pulled out. The tab 30 of the first cell 20A is connected to the tab 30 of the second cell 20B at the connecting portion 33 located between the base end portion 31 connected to the armor 25 and the distal end portion 32 farthest from the armor 25. are electrically connected in contact. According to such an embodiment, the region 35 from the connection portion 33 to the tip portion 32 of the tab 30 of the first cell 20A can function as a heat dissipation portion. Therefore, it is possible to effectively suppress the temperature rise of the cell 20 , especially the local temperature rise near the tab 30 . As a result, deterioration of the cell 20, especially local early deterioration near the tab 30 can be effectively avoided, and the service life of the cell 20 can be extended.

In one specific example of one embodiment described above, the first cells 20A and the second cells 20B may be stacked together. When the cells 20 are stacked, heat tends to be trapped, and the temperature rise of the cells 20 becomes more serious. The present embodiment is suitable for the cell assembly 15 and the storage element module 10 including a plurality of cells 20 stacked in this manner.

Although an embodiment has been described through several specific examples, these specific examples are not intended to limit an embodiment. The above-described embodiment can be implemented in various other specific examples, and various omissions, replacements, changes, additions, etc. can be made without departing from the spirit of the embodiment.

For example, in the specific example described above, an example in which the tabs 30 of the first cell 20A and the second cell 20B included in one cell assembly 15 have the same configuration was shown, but the present invention is not limited to this example, and the first cell 20A and the tabs 30 of the second cell 20B may have different configurations. For example, one of the tabs 30 of the first cell 20A and the tab 30 of the second cell 20B may not have the heat dissipation region 35 . The tab 30 of the first cell 20A and the tab 30 of the second cell 20B may have different configurations of heat dissipation regions 35 .

Moreover, in the specific example described above, an example in which the two cells 20 connected in series are electrically connected via the connecting wiring 12 is shown, but the present invention is not limited to this example. For example, as shown in FIG. 10, two cells 20 connected in series may be electrically connected by fixing the tabs 30 in contact with each other. In the storage element module 10 shown in FIG. 10, six cells 20 are electrically connected in series. In this example, two cells 20 connected in series form a cell assembly 15 . At least one of the tabs 30 of the two cells 20 forming the cell assembly 15 may include the heat dissipation region 35 .

Furthermore, in the specific example described above, an example was shown in which the cells 20 bulge only to one side in the first direction DA, but the present invention is not limited to this example. You may make it bulge out to both sides in.

10 Electric storage element module 12 Connecting wiring 15 Cell assembly 20 Cell 20A First cell 20B Second cell 21 Electrode assembly 22 Electrode plate 22A Positive electrode plate 22B Negative electrode plate 23 Insulator 25 Exterior 26 First exterior 27 Second exterior 27a Swelling portion 27b Collar portion 29 Sealing material 30 Tab 31 Base end portion 32 Tip portion 33 Connection portion 35 Heat dissipation region 36 Slit 37 Heat dissipation member DA First direction DB Second direction DC Third direction DL Stacking direction

Claims (15)

comprising a first cell and a second cell;
The first cell and the second cell are respectively composed of an electrode body including a plurality of electrode plates, an exterior body containing the electrode body, and an exterior body connected to the electrode body and extending to the outside of the exterior body. has tabs and
The tab of the first cell is in contact with the tab of the second cell at a connecting portion located between a base end connected to the armor and a tip farthest away from the armor. is electrically connected through
The cell combination body , wherein the tab of the first cell is provided with a slit in a portion closer to the distal end than the connecting portion. The tab of the second cell is in contact with the tab of the first cell at a connecting portion located between a proximal end connected to the armor and a distal end farthest from the armor. 2. The cell assembly of claim 1, electrically connected as a. 3. The cell assembly according to claim 2, wherein said tab of said second cell is spaced apart from said tab of said first cell at a portion closer to said tip than said connecting portion. 3. The tab of the first cell and the tab of the second cell are gradually separated from the connection portion electrically connected by contact with each other toward the tip portion side. or the cell assembly according to 3. The cell assembly according to any one of claims 1 to 4 , wherein said slit extends from said tip portion toward said connecting portion. The cell assembly according to any one of claims 1 to 4, wherein said slit extends from a side edge of said tab in a direction non-parallel to a direction connecting said tip portion and said connecting portion. 7. The cell assembly according to claim 6 , wherein said slits include a plurality of slits extending alternately from opposite side edges from said connection portion toward said tip portion. The cell assembly according to any one of claims 1 to 7 , wherein portions of said tabs located on both sides of said slit are separated from each other via said slit. The cell assembly according to any one of claims 1 to 8 , further comprising a heat radiating member in contact with a portion of the tab of the first cell that is closer to the tip than the connecting portion. 10. The cell assembly according to claim 9 , wherein said heat dissipating member includes heat dissipating fins. 11. The cell assembly according to claim 9 , wherein said heat radiating member is made of a material having higher thermal conductivity than said tab. The cell assembly according to any one of claims 1 to 11 , wherein said tab of said first cell is bent in a region closer to said tip than said connecting portion. 13. The cell assembly according to claim 12 , wherein the tabs of the first cells are bent multiple times alternately in opposite directions from the connection portion toward the tip portion. The cell assembly according to any one of claims 1 to 13 , wherein said first cell and said second cell are laminated together. A power storage element module comprising the cell assembly according to any one of claims 1 to 14 .

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