Cell stack

Abstract

To provide a cell laminate in which tab leads of a plurality of laminated cells and a conductive connection member can be connected in a space-saving manner.SOLUTION: A cell laminate 1 includes: a plurality of laminated cells 2 which are laminated. In each laminated cell 2, tab leads 21, 22 of the plurality of laminated cells 2 are electrically connected to each other via a conductive connection member 30 having a plate shape. The tab leads 21, 22 connected to the conductive connection member 30 have respective linear portions 211, 221 extending linearly in a direction perpendicular to a lamination direction from a sealing portion 20 to respective tip ends 21a, 22a. The tip ends 21a, 22a of the respective tab leads 21, 22 are bonded in close contact with the conductive connection member 30 by a surface, of the surface of the conductive connection member 30, which is parallel to an extension direction of the respective tab leads 21, 22 at an inside connection portion 47 located inside the conductive connection member 30 in the lamination direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a cell stack comprising a plurality of laminated cells stacked together. [Background technology]

[0002] In recent years, research and development into secondary batteries that contribute to energy efficiency has been conducted in order to ensure that more people have access to affordable, reliable, sustainable and advanced energy.

[0003] As a secondary battery, a laminated cell is known (for example, Patent Document 1). Patent Document 1 describes a structure in which cell electrodes of a plurality of laminated cells are welded to a bus bar to electrically connect the cell electrodes to each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-249243 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the cell electrodes of two adjacent laminate cells are connected in series via a bus bar, but in some cases, multiple laminate cells may be connected in parallel and in series. In this case, it is common to connect the cell electrodes via a bus bar, as in Patent Document 1.

[0006] Fig. 13 shows an example of a structure in which positive electrode tab leads 201 of two laminated type cells 200A connected in parallel and negative electrode tab leads 202 of two laminated type cells 200B connected in parallel are connected in series via a conductive connection member 300. Four laminated type cells are stacked in the left-right direction in the figure. Fig. 14 is a cross-sectional view taken along line ZZ in Fig. 13.

[0007] The positive electrode tab lead 201 of the laminated cell 200A on the outer side in the stacking direction and the negative electrode tab lead 202 of the laminated cell 200B are bent 90° from both ends in the stacking direction of the conductive connection member 300 and joined on the surface of the conductive connection member 300. Two slits 301 arranged side by side in the stacking direction are provided in the center of the conductive connection member 300, and the positive electrode tab lead 201 of the laminated cell 200A on the inner side in the stacking direction and the negative electrode tab lead 202 of the laminated cell 200B are inserted into the slits 301. The positive electrode tab lead 201 and the negative electrode tab lead 202 inserted into the slits 301 are then bent 90° and joined on the surface of the conductive connection member 300 between the two slits 301.

[0008] In the region between both ends 302 in the vertical direction of the conductive connection member 300, the slits 301 are provided, so that the conductive connection member 30 is not electrically connected to all of the positive electrode tab leads 201 and the negative electrode tab leads 202 in the stacking direction of the laminated cells 200A, 200B (see FIG. 14). Therefore, both ends 302 of the conductive connection member 300 function as conductive parts to electrically connect them. With the configuration shown in FIG. 13, a certain amount of space was required above and below the positive electrode tab lead 201 and the negative electrode tab lead 202 to provide both ends 302. Also, in order to ensure the conductive area of ​​both ends 302, the entire conductive connection member 300 was likely to become thick.

[0009] The present invention provides a cell stack that enables connection between tab leads of a plurality of laminate-type cells and conductive connecting members in a space-saving manner. [Means for solving the problem]

[0010] The present invention relates to A cell stack comprising a plurality of stacked laminate type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connection member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, The conductive connection member is provided with a plurality of slits, The tip end of the tab lead is inserted into each slit, In a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip portion of each tab lead and the conductive connection member are electrically connected, The two surfaces perpendicular to the stacking direction are The surface of the conductive connection member is parallel to the extending direction of the tab lead. And each slit is configured The conductive connection member is bonded to the conductive connection member by a surface contact. And, The conductive connection member is configured such that the length in the longitudinal direction of a portion located outside each slit is shorter than the length in the stacking direction of a portion located between adjacent slits. . The present invention also provides a method for producing a semiconductor device comprising the steps of: A cell stack comprising a plurality of stacked laminate type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connection member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, The conductive connection member is provided with a plurality of slits, The tip end of the tab lead is inserted into each slit, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip end of each tab lead and the conductive connection member are electrically connected, both surfaces of the tip end perpendicular to the stacking direction are joined in close contact with the conductive connection member by surfaces of the conductive connection member that are parallel to the extending direction of the tab leads and that form each slit, The entrance of each slit is chamfered. The present invention also provides a method for producing a semiconductor device comprising the steps of: A cell stack comprising a plurality of stacked laminate type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connection member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, The conductive connection member is provided with a plurality of slits, The tip end of the tab lead is inserted into each slit, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip end of each tab lead and the conductive connection member are electrically connected, both surfaces of the tip end perpendicular to the stacking direction are joined in close contact with the conductive connection member by surfaces of the conductive connection member that are parallel to the extending direction of the tab leads and that form each slit, Each slit has one longitudinal end open and the other end closed. The present invention also provides a method for producing a semiconductor device comprising the steps of: A cell stack comprising a plurality of stacked laminate type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connection member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip portion of each tab lead and the conductive connection member are electrically connected, the tip portion is joined to the conductive connection member so as to be in close contact with the conductive connection member on a surface of the conductive connection member that is parallel to an extending direction of the tab lead, the conductive connection members include a first conductive connection member, a second conductive connection member, and a third conductive connection member; the plurality of laminated type cells include a plurality of first laminated type cells adjacent to each other in the stacking direction and electrically connected in parallel, and a plurality of second laminated type cells adjacent to each other in the stacking direction and electrically connected in parallel, the tip ends of the tab leads of the first laminated cells are joined in close contact with the first conductive connection member at a surface of the first conductive connection member that is parallel to the extending direction of the tab leads, the tip ends of the tab leads of the second laminate type cells are joined in close contact with the second conductive connection member at a surface of the second conductive connection member that is parallel to the extending direction of the tab leads, The first conductive connection member and the second conductive connection member are electrically connected to each other via the third conductive connection member. Effect of the Invention

[0011] According to the present invention, the tab leads of a plurality of laminate type cells can be connected to the conductive connecting members in a space-saving manner. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic plan view of a cell stack 1 according to each embodiment of the present invention, and shows a schematic diagram of electrical paths in the cell stack 1. [Diagram 2] FIG. 2 is a perspective view of a laminated cell 2. [Diagram 3] 1 is a diagram showing connections of tab leads 21, 22 of six adjacent laminate type cells 2A, 2B in a cell stack 1 of the first embodiment. FIG. [Figure 4] FIG. 2 is a front view of the conductive connection member 30. [Diagram 5] 13 is a diagram showing that the conductive connection member 30 and the tab leads 21 and 22 are electrically connected without interruption in the stacking direction. [Figure 6] 2A to 2C are diagrams illustrating a method for manufacturing the cell stack 1 of the first embodiment. [Figure 7] 13 is a diagram showing a chamfered portion 34 of a conductive connection member 30 of Modified Example 1. FIG. [Figure 8] 11 is a front view of the conductive connection member 30 of the second modified example. FIG. [Figure 9] 13 is a diagram showing connections of tab leads 21, 22 of four adjacent laminate type cells 2A, 2B in a cell stack 1 of the second embodiment. FIG. [Figure 10]11 is a diagram illustrating the connection between tab leads 21, 22 of four adjacent laminate cells 2A, 2B and a conductive connecting member 40 in the second embodiment. FIG. [Figure 11] 11 is a diagram illustrating the connection between tab leads 21, 22 of eight adjacent laminate cells 2A, 2B and a conductive connecting member 40 in the second embodiment. FIG. [Figure 12] 11 is a diagram illustrating the connection between tab leads 21, 22 of six adjacent laminate cells 2A, 2B and a conductive connecting member 40 in the second embodiment. FIG. [Figure 13] FIG. 1 shows a conventional structure in which two laminate type cells 200A connected in parallel and two laminate type cells 200B connected in parallel are connected in series via a conductive connecting member 300. [Figure 14] 14 is a cross-sectional view taken along line ZZ in FIG. 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a cell stack according to each embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] First Embodiment A cell stack 1 according to a first embodiment of the present invention will be described. Fig. 1 is a schematic plan view of the cell stack 1. The cell stack 1 includes a plurality of laminated cells 2 stacked in the horizontal direction (the left-right direction in Fig. 1). Although not shown, the cell stack 1 is housed in a battery case and is disposed, for example, under the floor of the vehicle (below a floor panel).

[0015] FIG. 2 is a perspective view of a laminated cell 2. The laminated cell 2 is, for example, a solid-state battery. The laminated cell 2, which is a solid-state battery, has a positive electrode connected to a positive electrode tab lead 21, a negative electrode connected to a negative electrode tab lead 22, a solid electrolyte disposed between the positive electrode and the negative electrode, and a laminated film 23 that accommodates them, and is charged and discharged by the exchange of lithium ions between the positive electrode and the negative electrode via the solid electrolyte. In addition, a seal portion 20 is provided on the periphery of the laminated cell 2. When the positive electrode tab lead 21 and the negative electrode tab lead 22 are not to be distinguished from each other, they are also simply referred to as tab leads 21 and 22.

[0016] The positive electrode tab lead 21 extends from a seal portion 20 at one end in the longitudinal direction of the laminated cell 2, and the negative electrode tab lead 22 extends from a seal portion 20 at the other end in the longitudinal direction of the laminated cell 2. The positive electrode including the positive electrode tab lead 21 is formed from, for example, aluminum. The negative electrode including the negative electrode tab lead 22 is formed from, for example, copper.

[0017] The solid electrolyte of the solid-state battery is not particularly limited as long as it has lithium ion conductivity and insulating properties, and materials generally used in all-solid-state lithium ion batteries can be used. For example, inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, and lithium-containing salts, polymer-based solid electrolytes such as polyethylene oxide, and gel-based solid electrolytes containing lithium-containing salts and lithium ion conductive ionic liquids can be used. The form of the solid electrolyte material is not particularly limited, and can be, for example, particulate.

[0018] Returning to Fig. 1, the multiple laminated cells 2 are electrically connected in series from an electrical flow path start end 11 (positive electrode) to an electrical flow path end 12 (negative electrode) of the cell stack 1. The electrical flow path start end 11 and the electrical flow path end 12 are connected, for example, via a conductive connection member (e.g., a bus bar) to a junction box or other cell stack in which various wiring components are mounted.

[0019] Next, the connection of the positive electrode tab lead 21 and the negative electrode tab lead 22 of the multiple laminate type cells 2 will be described with reference to FIGS.

[0020] Fig. 3 shows the connection of the positive electrode tab lead 21 and the negative electrode tab lead 22 of six adjacent laminated cells 2. Fig. 3 shows the connection of the X part in Fig. 1 as an example, but the connection of the tab leads other than the X part is performed in the same manner. For convenience of explanation, of the six adjacent laminated cells 2, three laminated cells arranged at one end side in the stacking direction (right side in Fig. 3) are also denoted by the symbol 2A, and three laminated cells arranged at the other end side in the stacking direction (left side in Fig. 3) are also denoted by the symbol 2B, but each of the laminated cells 2A and 2B has the same configuration as the laminated cell 2 described above.

[0021] Of the six adjacent laminate type cells 2, three laminate type cells 2A are connected in parallel to each other, and three laminate type cells 2B are connected in parallel to each other. The three laminate type cells 2A connected in parallel and the three laminate type cells 2B connected in parallel are electrically connected in series via a conductive connection member 30. To explain in detail, the positive electrode tab leads 21 of the three laminate type cells 2A connected in parallel and the negative electrode tab leads 22 of the three laminate type cells 2B connected in parallel are connected to the conductive connection member 30, whereby the laminate type cells 2A and the laminate type cells 2B are electrically connected in series.

[0022] The conductive connection member 30 is a plate-shaped member, such as a bus bar, as shown in Fig. 4. In the example shown in Fig. 3, the tab leads 21, 22 of six laminate type cells 2 are connected to one conductive connection member 30.

[0023] The conductive connection member 30 has a plurality of slits 31. The number of slits 31 is equal to the number of laminated cells 2 connected to one conductive connection member 30, and is six in this embodiment. Each slit 31 extends in the vertical direction, and the tab leads 21, 22 are inserted into each slit 31.

[0024] Each of the tab leads 21, 22 connected to the conductive connection member 30 has a straight portion 211, 221 extending linearly in a direction perpendicular to the lamination direction from the seal portion 20 to the tip portion 21a, 22a. When connecting the conductive connection member having a slit to the tab lead, the tab lead is inserted into the slit and the tip portion of the tab lead that has passed through the slit may be bent (see FIG. 14 ). However, in this embodiment, the tab leads 21, 22 are not bent. That is, each of the tab leads 21, 22 is composed of the straight portion 211, 221 and is connected to the conductive connection member 30 at the straight portion 211, 221.

[0025] Tip portions 21a, 22a of tab leads 21, 22 are inserted into each slit 31. In the example shown in Fig. 3, the tips of tab leads 21, 22 (the parts of tip portions 21a, 22a that are farthest from seal portion 20) do not protrude outside each slit 31 in the extending direction of tab leads 21, 22. That is, the tips of tab leads 21, 22 are disposed inside each slit 31. However, the tips of tab leads 21, 22 may protrude outside each slit 31.

[0026] After inserting the tip portions 21a, 22a of the tab leads 21, 22 into each slit 31, when a load is applied to the conductive connection member 30 from both sides in the stacking direction of the laminated cell 2 (see the white arrows in Figure 4), the tip portions 21a, 22a are in close contact with the conductive connection member 30 on both sides perpendicular to the stacking direction, at the surfaces 31a parallel to the extension direction of the tab leads 21, 22 that constitute each slit 31.

[0027] As described above, in the first embodiment, in an inner connection portion 37 located on the inner side of the conductive connection member 30 in the stacking direction among the portions where the tip ends 21a, 22a of the tab leads 21, 22 are electrically connected to the conductive connection member 30, the tip ends 21a, 22a are in close contact with the conductive connection member 30 at a surface 31a of the conductive connection member 30 that is parallel to the extending direction of the tab leads 21, 22. Similarly, in an outer connection portion 38 located on the outer side of the conductive connection member 30 in the stacking direction among the portions where the tip ends 21a, 22a of the tab leads 21, 22 and the conductive connection member 30 are electrically connected, the tip ends 21a, 22a are in close contact with the conductive connection member 30 at the surface 31a.

[0028] In this state, the tab leads 21, 22 are joined to the conductive connection member 30. The joining of the tab leads 21, 22 and the conductive connection member 30 is performed by a predetermined joining process such as laser welding or ultrasonic joining. FIG. 5 shows the conductive connection member 30 after the joining process has been performed along each slit 31 into which the tab leads 21, 22 have been inserted. As shown in FIG. 5, a joint 50 is formed on the surface of the conductive connection member 30 along each slit 31. In this way, after the tab leads 21, 22 and the conductive connection member 30 are joined, each slit 31 is filled with the tab leads 21, 22 and the joint 50. Therefore, the conductive connection member 30 and the tab leads 21, 22 are stably conducted without interruption in the stacking direction (see the outlined arrows in FIG. 5).

[0029] As described above, in the inner connection portion 37 located inside the conductive connection member 30 in the stacking direction, the tip ends 21a, 22a of the laminate cells 2A, 2B are joined in close contact with the conductive connection member 30 at the surface 31a of the conductive connection member 30 that is parallel to the extension direction of the tab leads 21, 22, so that the conductive connection member 30 and the tab leads 21, 22 are electrically connected without interruption in the stacking direction. Therefore, unlike the configuration shown in Fig. 13, there is no need to increase the conductive area of ​​the portion of the conductive connection member 30 that is provided at a position that does not overlap with the tab leads 21, 22 when viewed from the stacking direction, i.e., the end 32 of the conductive connection member 30 on the longitudinal outer side of each slit 31. In other words, the end 32 of the conductive connection member 30 can be formed small. Furthermore, since the conductive connection member 30 and the tab leads 21, 22 are electrically connected without interruption in the stacking direction to ensure a sufficient conductive area, there is no need to thicken the conductive connection member 30 to ensure the conductive area, i.e., the conductive connection member 30 can be formed thin. Therefore, the tab leads 21, 22 of the multiple laminate type cells 2 and the conductive connection member 30 can be connected in a small space. In this way, the manufacturing cost and weight of the cell stack 1 can be reduced, and the cell stack 1 can be made more compact.

[0030] Furthermore, in this embodiment, the tip portions 21a, 22a, which are parts of the straight portions 211, 221 of the tab leads 21, 22, are joined to the conductive connecting member 30, eliminating the need for a bending process for the tab leads 21, 22. As there are no bent portions of the tab leads 21, 22, the length of the tab leads 21, 22 can be shortened accordingly, thereby reducing the manufacturing cost and weight of the multiple laminated cells 2. Furthermore, since the bending process is unnecessary, the productivity of the cell stack 1 is improved.

[0031] Incidentally, it is preferable that the end 32 of the conductive connection member 30 described above has a shape that is easily deformed when a load is applied to the conductive connection member 30 from both sides in the stacking direction. In order to facilitate deformation when a load is applied, the conductive connection member 30 is configured such that the longitudinal length t1 of the end 32 located on the longitudinal outer side of each slit 31 is shorter than the longitudinal length t2 of the portion 33 located between adjacent slits 31, as shown in Fig. 4 for example. This makes it easier for the tip portions 21a, 22a of the tab leads 21, 22 to come into close contact with the faces 31a of each slit 31 on both sides perpendicular to the stacking direction.

[0032] Next, a method for manufacturing the cell stack 1 of the first embodiment will be described with reference to FIG.

[0033] FIG. 6 is a diagram illustrating a manufacturing method of the cell stack 1. The manufacturing method of the cell stack 1 includes a stacking step, an insertion step, and a joining step. In the stacking step, a plurality of laminated cells 2 are stacked in the horizontal direction. After the stacking step, in the insertion step, the tab leads 21, 22 of the plurality of laminated cells 2 are inserted into the slits 31 of the conductive connection member 30. After the insertion step, in the joining step, the tab leads 21, 22 are joined to the conductive connection member 30 by, for example, laser welding along the slits 31 while a load is applied to the conductive connection member 30 from both sides in the stacking direction. In this manner, the cell stack 1 is manufactured.

[0034] (Variation 1) In the conductive connection member 30 of the first modification, the entrance of each slit 31 is chamfered, as shown in Fig. 7. More specifically, a chamfered portion 34 is formed at the entrance of each slit 31, which guides the insertion of the tab leads 21, 22 from the plate thickness direction of the conductive connection member 30. The chamfered portion 34 makes it easier to insert the tab leads 21, 22 into each slit 31.

[0035] (Variation 2) 8, in the conductive connection member 30 of the second modification, one end (here, the lower end) in the longitudinal direction of each slit 31 is open, and the other end (here, the upper end) is closed. In other words, the multiple slits 31 of the conductive connection member 30 are configured in a comb shape. With this configuration, for example, with multiple laminated cells 2 stacked in the horizontal direction, the tab leads 21, 22 can be easily inserted into the slits 31 by inserting the conductive connection member 30 into the tab leads 21, 22 from above.

[0036] In addition, the open lower end in the longitudinal direction of each slit 31 is chamfered. Specifically, a chamfered portion 35 is formed at the lower end of each slit 31, which guides the insertion of the conductive connection member 30 from above into the tab leads 21, 22. The chamfered portion 35 makes it easier to insert the tab leads 21, 22 into each slit 31.

[0037] Furthermore, in order to facilitate deformation when a load (indicated by an outlined arrow in FIG. 8) is applied to the conductive connection member 30 from both sides in the stacking direction, the conductive connection member 30 of the second modification is provided with a notch 36 at the upper end between adjacent slits 31. This makes it easier for the tip portions 21a, 22a of the tab leads 21, 22 to come into close contact with the faces 31a of the respective slits 31 on both sides perpendicular to the stacking direction.

[0038] Second Embodiment Next, a cell stack 1 according to a second embodiment of the present invention will be described. Since the laminated type cells 2 are the same as those in the first embodiment, the same reference numerals are used and the description thereof will be omitted. The direction in which the laminated type cells 2 are stacked is also the same as in the first embodiment, that is, the horizontal direction.

[0039] 9 and 10, a configuration in which the positive electrode tab lead 21 and the negative electrode tab lead 22 of four adjacent laminated cells 2 are connected via a conductive connection member 40. For convenience of explanation, of the four adjacent laminated cells 2, the two laminated cells arranged at one end side in the stacking direction (right side in FIG. 10) are also referred to as reference symbol 2A, and the two laminated cells arranged at the other end side in the stacking direction (left side in FIG. 10) are also referred to as reference symbol 2B. However, each of the laminated cells 2A and 2B has the same configuration as the laminated cell 2 described above.

[0040] Of the four adjacent laminate type cells 2, two laminate type cells 2A are connected in parallel to each other, and two laminate type cells 2B are connected in parallel to each other. The two laminate type cells 2A connected in parallel and the two laminate type cells 2B connected in parallel are electrically connected in series via a conductive connection member 40. To explain in detail, the positive electrode tab leads 21 of the two laminate type cells 2A connected in parallel and the negative electrode tab leads 22 of the two laminate type cells 2B connected in parallel are connected to the conductive connection member 40, whereby the laminate type cells 2A and the laminate type cells 2B are electrically connected in series.

[0041] The conductive connection member 40 includes a first conductive connection member 41, a second conductive connection member 42, and a third conductive connection member 43. The first conductive connection member 41, the second conductive connection member 42, and the third conductive connection member 43 are each a plate-shaped member, such as a bus bar.

[0042] The first conductive connection member 41 connects the positive electrode tab leads 21 of two adjacent laminated cells 2A to each other. In detail, the first conductive connection member 41 is disposed between two adjacent positive electrode tab leads 21, and the tip portion 21a of each positive electrode tab lead 21 is joined in close contact with the first conductive connection member 41 at a surface 41a of the first conductive connection member 41 that is parallel to the extension direction of the positive electrode tab lead 21. The positive electrode tab lead 21 and the first conductive connection member 41 are joined by laser welding, ultrasonic bonding, or the like.

[0043] The second conductive connection member 42 connects the negative electrode tab leads 22 of two adjacent laminated cells 2B. In detail, the second conductive connection member 42 is disposed between two adjacent negative electrode tab leads 22, and the tip portion 22a of each negative electrode tab lead 22 is joined in close contact with the second conductive connection member 42 at a surface 42a of the second conductive connection member 42 that is parallel to the extension direction of the negative electrode tab lead 22. The negative electrode tab lead 22 and the second conductive connection member 42 are joined by laser welding, ultrasonic bonding, or the like.

[0044] As described above, in the second embodiment as well, at an inner connection portion 47 located on the inner side of the conductive connection member 40 in the stacking direction among the portions where the tip ends 21a, 22a of the tab leads 21, 22 and the conductive connection member 40 are electrically connected, the tip ends 21a, 22a are joined in close contact to the conductive connection member 40 at surfaces 41a, 42a of the conductive connection member 40 that are parallel to the extension direction of the tab leads 21, 22. Similarly, at an outer connection portion 48 located on the outer side of the conductive connection member 40 in the stacking direction among the portions where the tip ends 21a, 22a of the tab leads 21, 22 and the conductive connection member 40 are electrically connected, the tip ends 21a, 22a are joined in close contact to the conductive connection member 40 at surfaces 41a, 42a.

[0045] The third conductive connection member 43 electrically connects the first conductive connection member 41 to which the positive electrode tab lead 21 is joined, and the second conductive connection member 42 to which the negative electrode tab lead 22 is joined. The third conductive connection member 43 is disposed outside the first conductive connection member 41 and the second conductive connection member 42 in the extension direction of the tab leads 21, 22, and is joined to and overlaps the first conductive connection member 41 and the second conductive connection member 42. The third conductive connection member 43 is joined to the first conductive connection member 41 and the second conductive connection member 42 by laser welding, ultrasonic bonding, or the like.

[0046] As described above, the first conductive connection member 41 to which the positive tab lead 21 is joined and the second conductive connection member 42 to which the negative tab lead 22 is joined are electrically connected via the third conductive connection member 43. According to this configuration, unlike the first embodiment and the configuration of FIG. 13, the tab leads 21, 22 and the conductive connection member 40 can be joined without providing a slit in the conductive connection member 40. Therefore, it is not necessary to provide a conductive connection member in the upper and lower regions of the tab leads 21, 22, as in the case of both end portions 302 in the configuration of FIG. 13, for example. In addition, since no slit is provided in the conductive connection member 40, the third conductive connection member 43 can be formed thinner than a conductive connection member having a slit.

[0047] In this embodiment, the first conductive connection member 41, the second conductive connection member 42, and the third conductive connection member 43 are preferably formed from the same type of metal material. This makes it easier to join the first conductive connection member 41 and the third conductive connection member 43, and to join the second conductive connection member 42 and the third conductive connection member 43.

[0048] Here, the first conductive connection member 41, the second conductive connection member 42, and the third conductive connection member 43 are preferably made of aluminum, for example. Aluminum is a relatively inexpensive and lightweight material, and therefore the manufacturing cost and weight of the cell stack 1 can be reduced.

[0049] In addition, when the positive electrode tab leads 21 of L (L is an even number equal to or greater than 4) laminated cells 2 connected in parallel and the negative electrode tab leads 22 of the L laminated cells 2 connected in parallel are electrically connected in series via the conductive connection members 40, the number of first conductive connection members 41 and the number of second conductive connection members 42 may be L / 2. As an example, FIG. 11 shows a case in which the positive electrode tab leads 21 of four laminated cells 2 connected in parallel and the negative electrode tab leads 22 of four laminated cells 2 connected in parallel are electrically connected in series via the conductive connection members 40. In this case, two first conductive connection members 41 and two second conductive connection members 42 are provided. The third conductive connection member 43 is electrically connected to the two first conductive connection members 41 and the two second conductive connection members 42.

[0050] Next, a configuration in which the positive electrode tab lead 21 and the negative electrode tab lead 22 of six adjacent laminated cells 2 are connected via a conductive connection member 40 will be described with reference to Fig. 12. For convenience of description, of the six adjacent laminated cells 2, three laminated cells arranged at one end side in the stacking direction (right side in Fig. 12) will also be referred to as reference symbol 2A, and three laminated cells arranged at the other end side in the stacking direction (left side in Fig. 12) will also be referred to as reference symbol 2B, but each of the laminated cells 2A and 2B has the same configuration as the laminated cell 2 described above.

[0051] Of the six adjacent laminate type cells 2, three laminate type cells 2A are connected in parallel to each other, and three laminate type cells 2B are connected in parallel to each other. The three laminate type cells 2A connected in parallel and the three laminate type cells 2B connected in parallel are electrically connected in series via the conductive connection members 40.

[0052] The conductive connection members 40 include two first conductive connection members 41, two second conductive connection members 42, and one third conductive connection member 43.

[0053] One of the two first conductive connection members 41 connects the positive electrode tab leads 21 of two adjacent laminated type cells 2A to each other. The other of the two first conductive connection members 41 connects to the positive electrode tab lead 21 of the remaining laminated type cell 2A at only one location. Note that the joining is similar to the configuration shown in Figures 9 and 10, so a description thereof will be omitted.

[0054] One of the two second conductive connection members 42 connects the negative electrode tab leads 22 of two adjacent laminated type cells 2B to each other. The other of the two second conductive connection members 42 connects to the negative electrode tab lead 22 of the remaining laminated type cell 2B at only one location.

[0055] That is, even in this case, at an inner connection portion 47 located on the inner side of the conductive connection member 40 in the stacking direction among the portions where the tip portions 21a, 22a of the tab leads 21, 22 and the conductive connection member 40 are electrically connected, the tip portions 21a, 22a are joined in close contact to the conductive connection member 40 at surfaces 41a, 42a of the conductive connection member 40 that are parallel to the extension direction of the tab leads 21, 22. Similarly, at an outer connection portion 48 located on the outer side of the conductive connection member 40 in the stacking direction among the portions where the tip portions 21a, 22a of the tab leads 21, 22 and the conductive connection member 40 are electrically connected, the tip portions 21a, 22a are joined in close contact to the conductive connection member 40 at surfaces 41a, 42a.

[0056] The third conductive connection member 43 electrically connects the two first conductive connection members 41 to which the positive electrode tab leads 21 are joined, and the two second conductive connection members 42 to which the negative electrode tab leads 22 are joined. With this configuration, the positive electrode tab leads 21 and negative electrode tab leads 22 of six adjacent laminated cells 2 can be connected via the conductive connection members 40.

[0057] In addition, when the positive electrode tab leads 21 of M (M is an odd number equal to or greater than 5) laminated cells 2 connected in parallel and the negative electrode tab leads 22 of M laminated cells 2 connected in parallel are electrically connected in series via conductive connection members 40, it is sufficient to prepare (M+1) / 2 first conductive connection members 41 and (M+1) / 2 second conductive connection members 42, respectively.

[0058] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that a person skilled in the art can come up with various modifications or alterations within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. In addition, the components in the above embodiments may be arbitrarily combined within the scope of the invention.

[0059] This specification describes at least the following items. In parentheses, components corresponding to the above-described embodiment are shown as examples, but the present invention is not limited to these.

[0060] (1) A cell stack (cell stack 1) having a plurality of stacked laminate-type cells (a plurality of laminate-type cells 2), Each laminated cell has a seal portion (seal portion 20) on its periphery, and tab leads (tab leads 21, 22) extend from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via plate-shaped conductive connection members (conductive connection members 30, 40); Each tab lead connected to the conductive connection member has a straight portion (straight portion 211, 221) extending straight in a direction perpendicular to the stacking direction from the seal portion to a tip portion (tip portion 21a, 22a), In a connection portion (inner connection portion 37, 47) located inside the conductive connection member in the stacking direction among the portion where the tip portion of each tab lead and the conductive connection member are electrically connected, the tip portion is joined in close contact with the conductive connection member at a surface (surface 31a, 41a, 42a) of the conductive connection member that is parallel to the extending direction of the tab lead. Cell stack.

[0061] According to (1), in the connection portion located inside the conductive connection member in the stacking direction, the tip portions of the multiple laminated type cells are joined in close contact with the conductive connection member on a surface of the conductive connection member that is parallel to the extension direction of the tab lead, so that the conductive connection member and the tab lead are electrically connected without interruption in the stacking direction. Therefore, the conductive area of ​​the portion of the conductive connection member that is provided at a position that does not overlap with the tab lead when viewed from the stacking direction can be reduced or eliminated. In addition, since the conductive connection member and the tab lead are electrically connected without interruption in the stacking direction and a sufficient conductive area is secured, it is not necessary to thicken the conductive connection member in order to secure the conductive area. Therefore, it is possible to save space at the connection points between the tab leads of multiple laminated type cells.

[0062] (2) The cell stack according to (1), The conductive connection member is provided with a plurality of slits (slits 31), The tip end of the tab lead is inserted into each slit, the tip end of the tab lead is joined in close contact with the conductive connection member on both surfaces perpendicular to the stacking direction and parallel to the extending direction of the tab lead that constitutes each slit; Cell stack.

[0063] According to (2), the tip end of the tab lead is inserted into each slit and joined in close contact with the conductive connecting member, so that the conductive connecting member and the tab lead are stably electrically connected in the stacking direction.

[0064] (3) The cell stack according to (2), the conductive connection member is configured such that a length in the longitudinal direction of a portion located outside each slit is shorter than a length in the stacking direction of a portion located between adjacent slits; Cell stack.

[0065] According to (3), the conductive connection members are easily deformed when a load is applied to both sides in the stacking direction, so that the conductive connection members and the tab leads can be easily brought into close contact with each other in each slit.

[0066] (4) The cell stack according to (2) or (3), The entrance of each slit is chamfered. Cell stack.

[0067] According to (4), it is easy to insert the tab leads into each slit.

[0068] (5) A cell stack according to any one of (2) to (4), Each slit has one longitudinal end open and the other longitudinal end closed. Cell stack.

[0069] According to (5), it becomes easy to insert the tab leads into each slit.

[0070] (6) The cell stack according to (1), the conductive connection member includes a first conductive connection member (first conductive connection member 41), a second conductive connection member (second conductive connection member 42), and a third conductive connection member (third conductive connection member 43); the plurality of laminated type cells include a plurality of first laminated type cells adjacent to each other in the stacking direction and electrically connected in parallel, and a plurality of second laminated type cells adjacent to each other in the stacking direction and electrically connected in parallel, the tip ends of the tab leads of the first laminated cells are joined in close contact with the first conductive connection member at a surface (surface 41a) of the first conductive connection member that is parallel to the extending direction of the tab leads, the tip ends of the tab leads of the second laminate type cells are joined in close contact with the second conductive connection member at a surface (surface 42a) of the second conductive connection member that is parallel to the extending direction of the tab leads, the first conductive connection member and the second conductive connection member are electrically connected to each other via the third conductive connection member; Cell stack.

[0071] According to (6), since the tab lead and the conductive connecting member can be joined without providing a slit in the conductive connecting member, the third conductive connecting member can be made thinner than a conductive connecting member having a slit.

[0072] (7) The cell stack according to (6), the first conductive connection member, the second conductive connection member, and the third conductive connection member are formed of the same type of metal material; Cell stack.

[0073] According to (7), the use of the same type of metal material facilitates joining of the first conductive connection member and the third conductive connection member, and joining of the second conductive connection member and the third conductive connection member.

[0074] (8) The cell stack according to (7), the first conductive connection member, the second conductive connection member, and the third conductive connection member are formed of aluminum; Cell stack.

[0075] According to (8), aluminum is a relatively inexpensive and lightweight material, which can reduce the manufacturing cost and weight of the cell stack. [Explanation of symbols]

[0076] 1 Cell stack 2. Laminated Cell 20 Seal part 21 Positive electrode tab lead (tab lead) 21a Tip 211 Straight section 22 Negative electrode tab lead (tab lead) 22a Tip 221 Straight section 30 Conductive connection member 31 Slit 37 Inner connection part (connection part) 40 Conductive connection member 41 First conductive connection member 42 Second conductive connection member 43 Third conductive connecting member 47 Inner connection part (connection part)

Claims

1. A cell stack comprising a plurality of stacked laminate type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connecting member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, The conductive connection member is provided with a plurality of slits, The tip end of the tab lead is inserted into each slit, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip end of each tab lead and the conductive connection member are electrically connected, both surfaces of the tip end perpendicular to the stacking direction are joined in close contact with the conductive connection member by surfaces of the conductive connection member that are parallel to the extending direction of the tab leads and that form each slit, the conductive connection member is configured such that a length in the longitudinal direction of a portion located outside each slit is shorter than a length in the stacking direction of a portion located between adjacent slits; Cell stack.

2. A cell stack comprising a plurality of stacked laminate-type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connecting member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, The conductive connection member is provided with a plurality of slits, The tip end of the tab lead is inserted into each slit, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip end of each tab lead and the conductive connection member are electrically connected, both surfaces of the tip end perpendicular to the stacking direction are joined in close contact with the conductive connection member by surfaces of the conductive connection member that are parallel to the extending direction of the tab leads and that form each slit, The entrance of each slit is chamfered. Cell stack.

3. A cell stack comprising a plurality of stacked laminate-type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connecting member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, The conductive connection member is provided with a plurality of slits, The tip end of the tab lead is inserted into each slit, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip end of each tab lead and the conductive connection member are electrically connected, both surfaces of the tip end perpendicular to the stacking direction are joined in close contact with the conductive connection member by surfaces of the conductive connection member that are parallel to the extending direction of the tab leads and that form each slit, Each slit has one longitudinal end open and the other longitudinal end closed. Cell stack.

4. A cell stack comprising a plurality of stacked laminate-type cells, Each laminated cell has a seal portion on its periphery, and a tab lead extends from the seal portion in a direction perpendicular to the stacking direction; the tab leads of at least four of the laminated cells are electrically connected to each other via a plate-shaped conductive connecting member; Each tab lead connected to the conductive connection member has a linear portion extending linearly in a direction perpendicular to the stacking direction from the seal portion to a tip portion, at a connection portion located inside the conductive connection member in the stacking direction among a portion where the tip portion of each tab lead and the conductive connection member are electrically connected, the tip portion is joined to the conductive connection member so as to be in close contact with the conductive connection member on a surface of the conductive connection member that is parallel to an extending direction of the tab lead, the conductive connection members include a first conductive connection member, a second conductive connection member, and a third conductive connection member; The plurality of laminated type cells include a plurality of first laminated type cells adjacent to each other in the stacking direction and electrically connected in parallel, and a plurality of second laminated type cells adjacent to each other in the stacking direction and electrically connected in parallel, the tip ends of the tab leads of the first laminate type cells are joined in close contact with the first conductive connection member at a surface of the first conductive connection member that is parallel to the extending direction of the tab leads, the tip ends of the tab leads of the second laminate type cells are joined in close contact with the second conductive connection member at a surface of the second conductive connection member that is parallel to the extending direction of the tab leads, the first conductive connection member and the second conductive connection member are electrically connected to each other via the third conductive connection member; Cell stack.

5. The cell stack according to claim 4, the first conductive connection member, the second conductive connection member, and the third conductive connection member are formed of the same type of metal material; Cell stack.

6. The cell stack according to claim 5 , the first conductive connection member, the second conductive connection member, and the third conductive connection member are formed of aluminum; Cell stack.

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