BATTERY CELL AND BATTERY MODULE

Abstract

A battery cell comprises: an outer laminate body (22) formed from a laminate containing a metal layer; an electrode body (25) housed within the outer laminate body (22), wherein a positive electrode and a negative electrode are laminated together in the electrode body, enclosing a separator between them; a pair of tabs (26, 28) each connected to the positive electrode and the negative electrode, respectively, and projecting from the outer laminate body (22); and a pair of conductive elements (30, 32, 52, 54) electrically connected to the metal layer and arranged to be separated from the tabs (26, 28), each conductive element coming into contact with the pair of tabs in conjunction with a bulge of the outer laminate body (22).

Description

BACKGROUNDTechnical area

[0001] The present disclosure relates to a battery cell and a battery module. Related art

[0002] Japanese Patent Application Laid-Open (JP-A) No. 2020-64881 discloses a pouch-type rechargeable battery comprising an electrode assembly (an electrode body) and an outer pouch body. Specifically, the outer pouch body of the pouch-type rechargeable battery described in JP-A No. 2020-64881 is structured by a first pouch portion and a second pouch portion, with a first electrode lead attached to the first pouch portion and a second electrode lead attached to the second pouch portion. In the pouch-type rechargeable battery described in JP-A No. 2020-64881, the first electrode lead and the second electrode lead are electrically connected by a foil-shaped connecting member. When the outer pouch body swells due to overcharging or the like, the foil-shaped connecting member ruptures, and charging is interrupted.

[0003] However, with the structure described in JP-A No. 2020-64881, it is difficult to reliably tear the film-shaped connecting member when the outer body of the bag swells. Furthermore, the film-shaped connecting member may inadvertently tear due to the application of an external force even at normal times when the outer body of the bag is not swelling. SUMMARY

[0004] The present disclosure provides a battery cell and a battery module that can suppress overcharging in a case where the battery cell is abnormal.

[0005] A battery cell according to a first aspect comprises: an outer laminate body formed of a laminate including a metal layer (metal sheet); an electrode body housed within the outer laminate body, in which a positive electrode and a negative electrode are laminated together with a separator therebetween; a pair of tabs (strips) respectively connected to the positive electrode and the negative electrode and projecting from the outer laminate body; and a pair of conductive members (pair of conductive members) electrically connected to the metal layer and arranged to be separated from the terminals, the conductive members each making contact with the pair of tabs in association with bulging (swelling) of the outer laminate body.

[0006] In the battery cell according to the first aspect, the outer laminate body is formed from the laminate including the metal layer, and the electrode body is housed within the outer laminate body. The tabs are respectively connected to the positive electrode and the negative electrode, which form the electrode body. These tabs protrude from the outer laminate body. Accordingly, the battery cell can be charged via the tabs.

[0007] A pair of conductive elements arranged separately from the tabs are also provided. The two conductive elements are each electrically connected to the metal layer of the laminate. In conjunction with swelling of the outer laminate body, the two conductive elements make contact with the respective tabs. Thus, when the outer laminate body swells, a short circuit occurs between the terminal (tab) on the positive electrode side and the terminal (tab) on the negative electrode side via the metal layer, and overcharging can be prevented. Then, when the outer laminate body returns from the swollen state to its original state, the short circuit state is separated.

[0008] In a battery cell according to a second aspect, in the first aspect, the laminate outer body includes exposed portions (exposed portions) at which the metal layer is exposed, and the pair of conductive members is connected to the metal layer at the exposed portions.

[0009] In the battery cell according to the second aspect, the exposed metal layer and the conductive elements are connected and conduct electricity. Therefore, a component for connecting each conductive element to the metal layer is not necessary, and the pair of tabs can be placed in states that enable short circuiting with a simple structure.

[0010] In a battery cell according to a third aspect, in the second aspect, the exposed portions are provided at locations that are not overlapped by the tabs when viewed in the lamination direction of the electrode body.

[0011] In the battery cell according to the third aspect, since each exposed portion is arranged at a position not overlapped by the tab in the lamination direction of the electrode body, unintentional conduction between the tab and the metal layer can be suppressed.

[0012] In a battery cell according to a fourth aspect, in the first aspect, the conductive elements are provided at locations that are not superimposed on the electrode body when viewed in the lamination direction of the electrode body.

[0013] In the battery cell according to the fourth aspect, each conductive element is provided at a location that is not overlapped with the electrode body when viewed in the lamination direction of the electrode body. Thus, the conductive element is arranged at a location where the cell is likely to swell, and the tab and the conductive element are likely to make contact in conjunction with cell swelling.

[0014] In a battery cell according to a fifth aspect, in the first aspect, at least a part of each conductive element is arranged at a position which is overlaid by the corresponding tab when viewed in the lamination direction of the electrode body.

[0015] In the battery cell according to the fifth aspect, since at least a part of the conductive member is arranged at a position superimposed on the tab when viewed in the lamination direction of the electrode body, the tab and the conductive member are likely to make contact in association with swelling of the cell.

[0016] In a battery cell according to a sixth aspect, in the first aspect, a whole of each tab is superimposed with a corresponding conductive element as viewed in the lamination direction of the electrode body.

[0017] In the battery cell according to the sixth aspect, since the entire tab as viewed in the lamination direction of the electrode body is superimposed with the conductive member, the tab and the conductive member are more securely brought into contact in association with swelling of the cell.

[0018] In a battery cell according to a seventh aspect, in the second aspect, each conductive member is connected to the metal layer at a connected portion, and as viewed in the lamination direction of the electrode body, one side of the conductive member including the connected portion is a tab-side contact portion capable of coming into contact with a corresponding tab, and another side with respect to the connected portion is a laminate-side contact portion.

[0019] In the battery cell according to the seventh aspect, the conductive member is provided with the tab-side contact portion (tab-side contact portion) on one side and the laminate-side contact portion (laminate-side contact portion) on the other side, as viewed in the lamination direction of the electrode body, with the bonded portion where the conductive member is bonded to the metal layer interposed therebetween. Thus, when the outer laminate body swells, the laminate-side contact portion and the tab-side contact portion move in opposite directions, rotating around the bonded portion, and the tab-side contact portion can be easily brought into contact with the tab.

[0020] In a battery cell according to an eighth aspect, in the seventh aspect, the contact portion on the tab side extends in a width direction of the tab by at least one width dimension of the tab.

[0021] In the battery cell according to the eighth aspect, the tab-side contact portion can come into contact with the entire width direction of the tab at a time of swelling of the laminate outer body and can be reliably short-circuited.

[0022] In a battery cell according to a ninth aspect, in the eighth aspect, each conductive member includes a pair of bridging portions connecting between the tab-side contact portion and the laminate-side contact portion, and the pair of bridging portions are each connected to the metal layer at the exposed portions.

[0023] In the battery cell according to the ninth aspect, since the bridge portions are connected to the metal layer, the connected state between the conductive element and the metal layer can be reliably maintained even when vibration, external force, or the like is applied. Furthermore, the effect of the contact portion on the tab side upon swelling of the laminate outer body can be more reliable than in a structure in which the conductive element and the metal layer are connected only at one location.

[0024] In a battery module according to a tenth aspect, a plurality of the battery cells according to any one of the first and ninth aspects are accommodated in a lined-up state.

[0025] In the battery module according to the tenth aspect, among the plurality of battery cells, only one abnormal battery cell in which the laminate outer body is swollen can be short-circuited.

[0026] In a battery module according to an eleventh aspect, in the tenth aspect, each tab is rotated in a direction away from the corresponding conductive element.

[0027] In the battery module according to the eleventh aspect, since the tab is rotated in the direction away from the conductive member, inadvertent contact between the conductive member and the tab can be suppressed at times when there is no swelling of the laminate outer body.

[0028] As described above, according to the battery cell and the battery module according to the present disclosure, overcharging can be reliably prevented only at times of an abnormality of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Exemplary embodiments of the present disclosure are described in detail with reference to the following figures, wherein: Fig. is a schematic plan view showing the main sections of a vehicle in which a battery pack is used. Fig. is a schematic perspective view of a battery module. Fig. is a plan view of a state in which a top cover of the battery module is removed. Fig. 4 is a schematic diagram showing a battery cell housed in the battery module in the thickness direction. Fig. 5 is an enlarged view of a main part showing an enlargement of main parts of a battery cell according to a first exemplary embodiment. Fig. Figure 6 is a sectional diagram showing a state taken along the line 6-6 in Fig. 5 is cut. Fig. 7 is a schematic diagram showing Fig. 6 when the battery cell has swollen. Fig. 8 is an enlarged view of a main portion showing an enlargement of main portions of a battery cell according to a second exemplary embodiment. Fig. 9 is a sectional diagram showing a state along the line 9-9 in Fig. 8 shows. Fig. 10 is a sectional diagram showing Fig. 9 when the battery cell has swollen. DETAILED DESCRIPTION = First exemplary version =

[0030] A battery pack 10 equipped with a battery module 11 according to a first exemplary embodiment will be described with reference to the drawings. - Overall structure of the vehicle 100 -

[0031] Fig. 1 is a schematic plan view showing the main portions of a vehicle 100 in which the battery pack 10 according to the exemplary embodiment is used. As shown in Fig. 1, the vehicle 100 is a battery electric vehicle (BEV) in which the battery pack 10 is mounted under the floor. The arrow UP, arrow FR, and arrow LH shown in the drawings respectively indicate the top in the vertical direction of the vehicle, the front in the front-to-rear direction of the vehicle, and the left side in the vehicle width direction. Hereinafter, the terms "front" and "rear," "left" and "right," and "top" and "bottom" are used. Unless otherwise specified, these terms refer to "front" and "rear" in the front-to-rear direction of the vehicle, "left" and "right" in the left-to-right direction of the vehicle, and "top" and "bottom" in the vertical direction of the vehicle.

[0032] For example, in the vehicle 100 according to the present exemplary embodiment, a DC-DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 are arranged at the front of the vehicle relative to the battery pack 10. A motor 108, a transmission 110, an inverter 112, and a charger 114 are arranged at the rear of the vehicle relative to the battery pack 10.

[0033] DC power output from the battery pack 10 is voltage-adjusted by the DC-DC converter 102 and supplied to the electric compressor 104, the PTC heater 106, the inverter 112, etc. Electrical power is supplied to the motor 108 via the inverter 112. This rotates the rear wheels and causes the vehicle 100 to travel.

[0034] A charging port 116 is provided at a right side portion of a rear portion of the vehicle 100. A charging plug of an external charger, not shown in the drawings, is connected via the charging port 116 and can cause electrical energy to accumulate in the battery pack 10 via the charger 114.

[0035] Arrangements, structures, and the like of components structuring the vehicle 100 are not limited by the above descriptions. For example, a hybrid vehicle (HV) or a plug-in hybrid electric vehicle (PHEV) in which a motor is mounted may be used as the vehicle. In the present exemplary embodiment, the vehicle 100 is a rear-wheel drive vehicle in which the motor 108 is mounted in a rear vehicle portion, but this is not limiting. A front-wheel drive vehicle in which the motor 108 is mounted in a front vehicle portion is possible, and a vehicle in which a pair of the motor 108 is mounted front and rear is also possible. A vehicle in which an in-wheel motor is provided at each wheel is also possible.

[0036] The battery pack 10 is constructed with a plurality of battery modules 11. For example, in the present embodiment, ten battery modules 11 are provided. Specifically, five of the battery modules 11 are arranged on the right side of the vehicle 100 in the front-to-rear direction of the vehicle, and five of the battery modules 11 are arranged on the left side of the vehicle 100 in the front-to-rear direction of the vehicle. The respective battery modules 11 are electrically connected.

[0037] Fig. 2 is a schematic perspective view of the battery module 11. As in Fig. As shown in Figure 2, each battery module 11 is substantially cuboid-shaped, with the longest direction in the width direction of the vehicle. An outer casing of the battery module 11 is formed from an aluminum alloy. The outer casing of the battery module 11 is formed, for example, by aluminum die-castings joined to both end portions of an extruded aluminum alloy member by laser welding or the like.

[0038] A pair of power terminals 12 and a connector 14 are provided at each of the two end portions of the battery module 11 in the vehicle width direction. A flexible printed circuit board (FPC) 21, described below, is connected to the connector 14. Bus bars, not shown in the drawings, are welded to the two end portions of the battery module 11 in the vehicle width direction.

[0039] A length MW of the battery module 11 in the vehicle width direction is, for example, 350 to 600 mm, a length ML of the battery module 11 in the vehicle front and rear direction is, for example, 150 to 250 mm, and a length MH of the battery module 11 in the vehicle vertical direction is, for example, 80 to 110 mm.

[0040] Fig. 3 is a plan view of a state in which a top cover of the battery module 11 is removed. As shown in Fig. As shown in Figure 3, a plurality of battery cells 20 are housed within the battery module 11 in an arrayed configuration. For example, in the present exemplary embodiment, 24 of the battery cells 20 are arranged in the front-to-rear direction of the vehicle and bonded together.

[0041] The flexible circuit board 21 is arranged above the battery cells 20. The flexible circuit board 21 is formed in a strip shape, the length of which runs in the vehicle width direction. A thermistor 23 is provided at each of the two end portions of the flexible circuit board 21. Each thermistor 23 is not glued to the battery cells 20, but is pressed against the battery cells 20 by the upper cover of the battery module 11.

[0042] Fig. 4 is a schematic diagram in which one of the battery cells 20 accommodated in the battery module 11 is seen in a thickness direction thereof. As shown in Fig. As shown in Figure 4, the battery cell 20 is formed substantially in a rectangular plate shape, inside which an electrode body 25 is housed. The electrode body 25 is sealed by an outer laminate body 22 formed from a laminate material. For clarity, conductive elements 30 and 32, which are main components of the present disclosure, are shown in Fig. 4 is not shown. Details of the structure of the end portions of the battery cell 20, including the conductive elements 30 and 32, are described below.

[0043] For example, in the battery cell 20 according to the present exemplary embodiment, an electrode body receiving portion is formed by the laminate outer body 22 in the form of an embossed film that is folded over and adhered to itself. A single-cap embossed structure in which a single region is embossed, or a double-cap embossed structure in which two regions are embossed, may be used. The present exemplary embodiment has a single-sided embossed structure with an embossing depth of approximately 8 to 10 mm.

[0044] The upper ends of both longitudinal end portions of the battery cell 20 are folded over, forming corners. An upper end portion of the battery cell 20 is folded over, and a fixing band 24 is wrapped around the upper end portion of the battery cell 20 along the longitudinal direction.

[0045] Respective tabs (terminals) are provided at both end portions in the longitudinal direction of the battery cell 20. More specifically, a tab on the positive electrode 26 side is provided on one side in the longitudinal direction of the battery cell 20, and a tab on the negative electrode 28 side is provided on the other side in the longitudinal direction of the battery cell 20.

[0046] A vehicle width direction CW1 of the battery cell 20 is, for example, 530 to 600 mm, a length CW2 of a region accommodating the electrode body is, for example, 500 to 520 mm, and a height CH of the battery cell 20 is, for example, 80 to 110 mm. The thickness of the battery cell 20 is 7.0 to 9.0 mm, and the thickness TH of the terminals is 40 to 50 mm. - Battery cell 20 -

[0047] Fig. 5 is an enlarged view of a main portion showing an enlargement of main portions of the battery cell 20 according to the first exemplary embodiment. As shown in Fig. As shown in Figure 5, the laminate outer body 22 structuring the battery cell 20 according to the present exemplary embodiment is formed by coating a metal layer with resin. Exposed portions 22A, where the metal layer is partially exposed, are provided at both longitudinal end portions of the laminate outer body 22.

[0048] The exposed portions 22A are provided in pairs at the two end portions in the longitudinal direction of the laminate outer body 22 at positions offset upward and downward, respectively, from the center of a short direction of the laminate outer body 22 (the vertical direction). Thus, the exposed portions 22A are provided at positions not overlapped by the positive electrode-side tab 26 and the negative electrode-side tab 28, as viewed in the lamination direction of the electrode body 25. Each exposed portion 22A is formed, for example, by exposing the metal layer by removing a resin layer of the laminate outer body 22.

[0049] The electrode body 25, housed in the outer laminate body 22, is structured by a positive electrode 25A and a negative electrode 25B laminated together and enclosing a separator not shown in the drawings. In the present exemplary embodiment, the negative electrode 25B is slightly larger than the positive electrode 25A. When forming a battery module, the positive electrode-side tab 26 is folded back to the opposite side from the side where the positive electrode-side conductive member 30 is arranged, and the negative electrode-side tab 28 is folded back to the opposite side from the side where the negative electrode-side conductive member 32 is arranged.More specifically, the positive electrode side strip 26 is bent back in the lamination direction of the electrode body 25 to the further side of the drawing, which is on the opposite side of the surface of the drawing on which the positive electrode side conductive member 30 is provided, and the negative electrode side strip 28 is bent back in the lamination direction of the electrode body 25 to the further side of the drawing on the opposite side of the surface of the drawing on which the negative electrode side conductive member 32 is provided.

[0050] The positive electrode-side tab 26 is a metal plate that is substantially rectangular in shape when viewed in the lamination direction of the electrode body 25. One end portion of the positive electrode-side tab 26 is connected to an end portion of the positive electrode 25A within the outer laminate body 22. The other end portion of the positive electrode-side tab 26 protrudes from the outer laminate body 22.

[0051] The negative electrode-side strip 28 is a metal plate substantially rectangular in shape in the lamination direction of the electrode body 25. One end portion of the negative electrode-side strip 28 is connected to an end portion of the negative electrode 25B inside the outer laminate body 22. The other end portion of the negative electrode-side strip 28 protrudes from the outer laminate body 22.

[0052] The positive electrode-side conductive member 30 is provided on a positive electrode side of the battery cell 20 and formed in a substantially rectangular frame shape as viewed in the lamination direction of the electrode body 25. Specifically, the positive electrode-side conductive member 30 is structured with a laminate-side contact portion 30A and a tab-side contact portion 30B. The laminate-side contact portion 30A extends across the outer laminate body 22 in the short direction of the battery cell 20. The tab-side contact portion 30B is disposed above the positive electrode-side tab 26 and extends substantially parallel to the laminate-side contact portion 30A.The positive electrode-side conductive member 30 is also provided with a pair of bridging portions 30C extending in the longitudinal direction of the battery cell 20 and connecting corresponding end portions of the laminate-side contact portion 30A and the tab-side contact portion 30B.

[0053] The laminate-side contact portion 30A of the positive electrode-side conductive member 30 is disposed on the side of an end portion of the battery cell 20 relative to the positive electrode 25A and negative electrode 25B of the electrode body 25. The laminate-side contact portion 30A is bonded to a surface of the outer laminate body 22 by an adhesive, adhesive tape, or the like. Thus, when an abnormality occurs, such as when a gas fills the interior of the outer laminate body 22, the laminate-side contact portion 30A is displaced in association with swelling of the outer laminate body 22. However, it should be noted that the laminate-side contact portion 30A does not need to be bonded to the laminate-side outer body 22. In this case, the laminate-side contact portion 30A would be displaced by being pushed out in association with swelling of the laminate-side outer body 22.

[0054] The tab-side contact portion 30B of the positive-electrode-side conductive member 30 is arranged so that it can be separated from the positive-electrode-side tab-like member 26 at usual times. The tab-side contact portion 30B extends over at least one width dimension of the positive-electrode-side tab-like member 26. As shown in Fig. 6, a cross-sectional shape of the tab-side contact portion 30B is formed substantially in a hat shape open to the side where the tab-side positive electrode portion 26 is disposed, which is a shape bypassing the tab-side positive electrode portion 26.

[0055] As in Fig. 5, the two bridging portions 30C are in a state of superposition with the exposed portions 22A and are connected to the metal layer of the laminate outer body 22 at the exposed portions 22A. The connection between the bridging portions 30C and the metal layer is established, for example, by ultrasonic welding or the like.

[0056] In this way, the positive electrode-side conductive member 30 is electrically connected to the metal layer at the exposed portions 22A and arranged so that it can be separated from the positive electrode-side tab 26. Viewed in the lamination direction of the electrode body 25, one side of the positive electrode-side conductive member 30, including connected portions where the positive electrode-side conductive member 30 is connected to the metal layer, serves as the tab-side contact portion 30B capable of contacting the positive electrode-side tab 26, and the other side with respect to the connected portions serves as the laminate-side contact portion 30A, which is arranged at a position of the outer laminate body 22 that is not overlaid by the electrode body 25.

[0057] The tab-side contact portion 30B of this conductive member 30 on the positive electrode side is configured to contact the tab 26 on the positive electrode side in conjunction with the expansion of the outer laminate body 22. That is, at the time of the expansion of the laminate outer body 22, the laminate-side contact portion 30A is pushed out by the laminate outer body 22 and moved to the nearer side of the drawing of Fig. 5 is postponed.

[0058] Since the exposed portions 22A are arranged at the end portion of the laminate outer body 22 and are connected to the pair of bridge portions 30C, the exposed portions 22A do not swell or swell very little. Therefore, the contact portion 30B on the tab side of the conductive member 30 on the positive electrode side is shifted to the opposite side of the laminate-side contact portion 30A, that is, to the farther side of the drawing in Fig. 5, and pivots around the exposed sections 22A. As in Fig. 7, this causes contact between the tab-side contact portion 30B and the positive electrode-side tab 26, and conducts electricity between the positive electrode-side tab 26 and the metal layer at the exposure portions 22A.

[0059] Meanwhile, the negative electrode-side conductive member 32 is provided on the negative electrode side of the battery cell 20 and formed in a shape symmetrical to the positive electrode-side conductive member 30. Specifically, the negative electrode-side conductive member 32 is structured with a laminate-side contact portion 32A and a tab-side contact portion 32B. The laminate-side contact portion 32A extends across the outer laminate body 22 in the short direction of the battery cell 20. The tab-side contact portion 32B is disposed above the negative electrode-side tab 28 and extends substantially parallel to the laminate-side contact portion 32A.The negative electrode-side conductive member 32 is also provided with a pair of bridging portions 32C extending in the longitudinal direction of the battery cell 20 and connecting corresponding end portions of the laminate-side contact portion 32A and the tab-side contact portion 32B.

[0060] The laminate-side contact portion 32A of the negative-electrode-side conductive member 32 is disposed on the side where one end portion of the battery cell 20 is located relative to the positive electrode 25A and the negative electrode 25B of the electrode body 25. The laminate-side contact portion 32A is bonded to a surface of the laminate outer body 22 by an adhesive, adhesive tape, or the like. Thus, when an abnormality occurs, such as when a gas fills the interior of the laminate outer body 22, the laminate-side contact portion 32A is displaced in association with the swelling of the laminate outer body 22. However, it should be noted that the laminate-side contact portion 32A does not need to be bonded to the laminate outer body 22. In this case, the laminate-side contact portion 32A would be displaced by being pushed out in association with the swelling of the laminate outer body 22.

[0061] The tab-side contact portion 32B of the negative electrode-side conductive member 32 is arranged so that it can be separated from the negative electrode-side tab 28 at usual times. The tab-side contact portion 32B extends over at least one width dimension of the negative electrode-side tab 28. The cross-sectional shape of the tab-side contact portion 32B is substantially hat-shaped, similar to the positive electrode-side conductive member 30, which has a shape that bypasses the negative electrode-side tab 28.

[0062] The pair of bridging portions 32C are in a state of superposition with the exposed portions 22A and are connected to the metal layer of the laminate outer body 22 at the exposed portions 22A. The connection between the bridging portions 32C and the metal layer is established, for example, by ultrasonic welding or the like.

[0063] In this way, the negative electrode-side conductive member 32 is electrically connected to the metal layer at the exposed portions 22A and is arranged so as to be separable from the negative electrode-side tab 28. One side of the negative electrode-side conductive member 32, including the connected portions where the negative electrode-side conductive member 32 is connected to the metal layer, serves as a tab-side contact portion 32B connected to the tab 28, and the other side with respect to the connected portions serves as a laminate-side contact portion 32A located at a position of the outer laminate body 22 that is not overlaid by the electrode body 25.

[0064] This tab-side contact portion 32B of the negative electrode-side conductive member 32 is configured to contact the tab 28 on the negative electrode side in conjunction with the expansion of the outer laminate body 22. That is, at the time of the expansion of the outer laminate body 22, the laminate-side contact portion 32A is pushed out by the outer laminate body 22 and moved to the nearer side of the drawing of Fig. 5 is postponed.

[0065] The tab-side contact portion 32B of the conductive member 32 on the negative electrode side is shifted to the opposite side of the laminate-side contact portion 32A, that is, to the farther side of the drawing in Fig. 5, while pivoting around the exposed portions 22A. As a result, the contact portion 32B on the tab side comes into contact with the tab 28 on the negative electrode side, and electricity is conducted between the tab 28 on the negative electrode side and the metal layer at the exposed portions 22A. Thus, a structure is formed such that the positive electrode-side tab 26 and the negative electrode-side tab 28 are short-circuited via the positive electrode-side conductive member 30, the negative electrode-side conductive member 32, and the metal layer at the time of swelling of the laminate outer body 22. - Operation -

[0066] Now, the operation of the battery cell 20 and the battery module 11 according to the present exemplary embodiment will be described.

[0067] In the battery cell 20 according to the present exemplary embodiment, the laminate outer body 22 is formed from the laminate including the metal layer, and the electrode body 25 is housed inside the laminate outer body 22. The positive electrode-side terminal 26 is connected to the positive electrode 25A that structures the electrode body 25, and the negative electrode-side terminal 28 is connected to the negative electrode 25B. The positive electrode-side terminal 26 and the negative electrode-side terminal 28 protrude from the outer laminate body 22. Therefore, the battery cell can be charged via the positive electrode-side tab 26 and the negative electrode-side tab 28.

[0068] The battery cell 20 is provided with the positive electrode-side conductive member 30, which is arranged separately from the positive electrode-side tab 26, and the negative electrode-side conductive member 32, which is arranged separately from the negative electrode-side tab 28. The positive electrode-side conductive member 30 and the negative electrode-side conductive member 32 are each electrically connected to the metal layer of the laminate. In conjunction with swelling of the outer laminate body 22, the positive electrode-side conductive member 30 makes contact with the positive electrode-side tab 26, and the negative electrode-side conductive member 32 makes contact with the negative electrode-side tab 28. Thus, the positive electrode-side tab 26 and the negative electrode-side tab 28 can be short-circuited, and overcharging can be prevented.When the outer laminate body 22 returns from the swollen state to its original state, the short-circuit state is interrupted.

[0069] In the present exemplary embodiment, both the positive electrode-side conductive member 30 and the negative electrode-side conductive member 32 are connected to the metal layer at the exposed portions 22A and conduct electricity. Therefore, a component for connecting each conductive member to the metal layer is not necessary, and the positive electrode-side tab 26 and the negative electrode-side tab 28 can be placed in states that enable short circuiting with a simple structure.

[0070] In the present exemplary embodiment, since the exposed portions 22A are arranged at positions not overlapped by the positive electrode side terminal 26 and the negative electrode side terminal 28 in the lamination direction of the electrode body 25, unintentional conduction between these terminals and the metal layer can be suppressed.

[0071] In the present exemplary embodiment, the positive electrode-side conductive member 30 and the negative electrode-side conductive member 32 are provided with the tab-side contact portions 30B and 32B on one side, which define the joined portions where the positive electrode-side conductive member 30 and the negative electrode-side conductive member 32 are joined to the metal layer, and are provided with the laminate-side contact portions 30A and 32A on the other side. Therefore, when the laminate outer body 22 swells, the laminate-side contact portions 30A and 32A and the tab-side contact portions 30B and 32B move in opposite directions while pivoting about the joined portions, and the tab-side contact portions 30B and 32B can be easily brought into contact with the positive electrode-side tab 26 and the negative electrode-side tab 28.

[0072] In the present exemplary embodiment, at the time of swelling of the laminate outer body 22, the tab-side contact portion 30B can contact the entire width direction of the tab-side positive electrode contact 26, and the tab-side contact portion 32B can contact the entire width direction of the tab-side negative electrode contact 28. Therefore, the tab-side contact portions 30B and 32B can be reliably short-circuited.

[0073] In the present exemplary embodiment, since the pair of bridging portions 30C are connected to the metal layer, the connected state between the positive electrode-side conductive member 30 and the metal layer can be securely maintained even when vibration, external force, or the like is applied. Since the pair of bridging portions 32C are connected to the metal layer, the connected state between the negative electrode-side conductive member 32 and the metal layer can be securely maintained even when vibration, external force, or the like is applied.In addition, the actions of the tab-side contact portions 30B and 32B at the time of swelling of the outer laminate body 22 can be made more reliable than in a structure in which the positive electrode-side conductive member 30 and the negative electrode-side conductive member 32 are each connected to the metal layer at only one location.

[0074] In the present exemplary embodiment, since the positive electrode-side strip 26 is rotated in the direction away from the positive electrode-side conductive member 30 and the positive electrode-side tab 26 at times when the laminate outer body 22 is not swelling, accidental contact between the positive electrode-side conductive member 30 and the positive electrode-side tab 26 can be suppressed. Similarly, since the negative electrode-side tab 28 is rotated in the direction away from the negative electrode-side conductive member 32, accidental contact between the negative electrode-side conductive member 32 and the negative electrode-side tab 28 can be suppressed at times when the laminate outer body 22 is not swelling.

[0075] In the battery module 11 according to the present exemplary embodiment, the battery cells 20 according to the present exemplary embodiment are housed in a plurality of arrayed cells. Accordingly, among the plurality of battery cells 20, only one abnormal battery cell 20 in which the laminate outer body 22 is swollen can be short-circuited, and the other normal battery cells 20 can be charged. = Second exemplary embodiment =

[0076] A battery cell 50 according to a second exemplary embodiment will now be described with reference to the drawings. Structures identical to those of the first exemplary embodiment are denoted by the same reference symbols and may not be described.

[0077] Fig. 8 is an enlarged view of a main portion showing an enlargement of main portions of the battery cell 50 according to the second exemplary embodiment. Fig. Figure 9 is a sectional diagram showing a state taken along the line 9-9 in Fig. 8 is cut. Fig. 10 is a sectional diagram showing Fig. 9 when the battery cell 50 is swollen. As in Fig. As shown in Figure 8, the laminate outer body 22 structuring the battery cell 50 according to the present exemplary embodiment is formed by coating a metal layer with resin. The exposed portions 22A, where the metal layer is partially exposed, are provided at both end portions in the longitudinal direction of the laminate outer body 22.

[0078] The exposed portions 22A are provided at locations not overlapped by the positive electrode-side tab 26 and the negative electrode-side tab 28, as viewed in the lamination direction of the electrode body 25. Each exposed portion 22A is formed, for example, by exposing the metal layer by removing a resin layer of the laminate outer body 22.

[0079] The electrode body 25, housed in the outer laminate body 22, is structured by the positive electrode 25A and the negative electrode 25B, which are laminated together and enclose a separator not shown in the drawings. In the present exemplary embodiment, the negative electrode 25B is slightly larger than the positive electrode 25A.

[0080] When forming a battery module, the positive electrode side tab 26 is bent back to the opposite side from the side where a positive electrode side conductive member 52, which will be described below, is arranged, and the negative electrode side tab 28 is bent back to the opposite side from the side where a negative electrode side conductive member 54, which will be described below, is arranged. For example, in the present exemplary embodiment, the positive electrode side tab 26 and the negative electrode side tab 28 are provided at portions of the battery cell 50 that are offset downward relative to the vertical direction of the center of the battery cell 50. The positive electrode side tab 26 and the negative electrode side tab 28 are connected to bus bars, which are not shown in the drawings, for example, by laser welding or the like.

[0081] The positive electrode-side conductive member 52 is configured with a laminate-side contact portion 52A, a tab-side contact portion 52B, and a connecting portion 52C. The laminate-side contact portion 52A is disposed above the outer laminate body 22 at a position not overlapped by the electrode body 25 and is bonded to a surface of the outer laminate body 22 by an adhesive, adhesive tape, or the like. Thus, the laminate-side contact portion 52A is displaced in response to an abnormality such as gas filling the interior of the outer laminate body 22, accompanied by swelling of the outer laminate body 22.

[0082] The tab-side contact portion 52B is arranged above the tab 26 of the positive electrode side on the outside relative to the laminate outer body 22. As shown in Fig. 9, the tab-side contact portion 52B is bent back relative to the connecting portion 52C in the direction away from the positive electrode-side tab 26, thereby forming a shape that suppresses inadvertent contact between the positive electrode-side conductive member 52 and the positive electrode-side tab 26 at times when the laminate outer body 22 does not swell.

[0083] As in Fig. As shown in Fig. 8, the connecting portion 52C connects the laminate-side contact portion 52A to the tab-side contact portion 52B. A portion of the connecting portion 54C is a connecting portion 54D that is superimposed on the exposed portion 22A and connected to the exposed portion 22A. Accordingly, one side of the conductive member 52 on the positive electrode side relative to the connected portion 52D serves as the tab-side contact portion 52B, and the other side relative to the connected portion 52D serves as the laminate-side contact portion 52A.

[0084] The negative electrode-side conductive member 54 has substantially the same shape as the positive electrode-side conductive member 52 and is arranged with left-right symmetry with the positive electrode-side conductive member 52. The negative electrode-side conductive member 54 is structured with a laminate-side contact portion 54A, a tab-side contact portion 54B, and a connecting portion 54C. The laminate-side contact portion 54A is disposed above the outer laminate body 22 at a position not overlapped by the electrode body 25 and is bonded to the surface of the outer laminate body 22 by an adhesive, adhesive tape, or the like. Therefore, in the event of an abnormality, such as when a gas fills the interior of the outer laminate body 22, the laminate-side contact portion 54A is displaced in association with the swelling of the outer laminate body 22.

[0085] The tab-side contact portion 54B is disposed above the negative electrode tab-side portion 28 on the outside relative to the outer laminate body 22. Similar to the tab-side contact portion 52B of the positive electrode conductive member 52, the tab-side contact portion 54B is bent back relative to the connecting portion 54C in the direction away from the negative electrode-side tab 28, thereby forming a shape that suppresses accidental contact between the negative electrode-side conductive member 54 and the positive electrode-side tab 26 at times when the laminate outer body 22 is not swelling.

[0086] As in Fig. 8, the connecting portion 54C connects the laminate-side contact portion 54A to the tab-side contact portion 54B. A portion of the connecting portion 54C is a connecting portion 54D that is superimposed on the exposed portion 22A and connected to the exposed portion 22A. Accordingly, one side of the conductive member 54 on the negative electrode side relative to the connected portion 54D serves as the tab-side contact portion 54B, and the other side relative to the connected portion 54D serves as the laminate-side contact portion 54A.

[0087] The positive electrode-side conductive member 52 and the negative electrode-side conductive member 54 are constructed as described above. Therefore, when the laminate outer body 22 swells, the laminate-side contact portion 52A of the positive electrode-side conductive member 52 and the laminate-side contact portion 54A of the negative electrode-side conductive member 54 are pushed out through the laminate outer body 22 and toward the nearer side of the drawing of Fig. 8 postponed.

[0088] The tab-side contact portion 52B of the positive electrode side conductive member 52 and the tab-side contact portion 54B of the negative electrode side conductive member 54 are offset to the opposite sides of the laminate-side contact portions 52A and 54A, that is, to the farther side of the drawing of Fig. 8, pivoting around the exposed sections 22A. As in Fig.10, this causes contact between the tab-side contact portion 52B of the positive electrode-side conductive member 52 and the positive electrode-side tab 26, and conducts electricity between the positive electrode-side tab 26 and the metal layer at the exposure portion 22A.

[0089] Similar to the tab-side contact portion 52B, the tab-side contact portion 54B of the negative electrode-side conductive member 54 makes contact with the negative electrode-side tab 28, and electricity is conducted between the negative electrode-side tab 28 and the metal layer of the exposed portion 22A. Thus, a structure is formed such that the positive electrode-side tab 26 and the negative electrode-side tab 28 are short-circuited via the positive electrode-side conductive member 52, the negative electrode-side conductive member 54, and the metal layer at the time of swelling of the laminate outer body 22. - Leading elements -

[0090] The shapes of the conductive elements are not limited to those shown in the first exemplary embodiment and the second exemplary embodiment. Examples of conductive elements include rectangular shapes, circular shapes, trapezoidal shapes, triangular shapes, etc. - Operation -

[0091] Now, the operation of the battery cell 50 according to the present exemplary embodiment will be described.

[0092] In the battery cell 50 according to the present exemplary embodiment, the positive electrode-side tab 26 and the negative electrode-side tab 28 can be short-circuited by a simpler structure than in the first exemplary embodiment. Other operations are similar to those in the first exemplary embodiment.

[0093] The battery cell 20 and the battery module 11 are described above in accordance with the present exemplary embodiments, but are not limited thereto. It is clear that numerous embodiments are possible within a range that does not deviate from the gist of the present disclosure. In the exemplary embodiments described above, the positive electrode-side conductive member 30 and the metal layer are connected at the exposed portions 22A, but this is not limiting. For example, terminals made of the metal layer may protrude from the outer laminate body 22 instead of providing the exposed portions 22A on the outer laminate body 22, and the positive electrode-side conductive member 30 may be connected to these terminals. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-64881 [0002, 0003]

Claims

[1] Battery cell (20) with: a laminate outer body (22) formed from a laminate containing a metal layer; an electrode body (25) housed inside the laminate outer body (22), wherein a positive electrode and a negative electrode are laminated together in the electrode body such that a separator is arranged between them; a pair of tabs (26, 28) connected to the positive electrode and the negative electrode, respectively, and projecting from the outside of the laminate outer body (22); and a pair of conductive elements (30, 32, 52, 54) electrically connected to the metal layer and arranged to be separate from the tabs (26, 28), the conductive elements each making contact with the pair of tabs in association with swelling of the laminate outer body (22). [2] The battery cell (20) according to claim 1, wherein the laminate outer body (22) has exposed portions where the metal layer is exposed, and the pair of conductive members (30, 32, 52, 54) are connected to the metal layer at the exposed portions (22A). [3] The battery cell according to claim 2, wherein the exposed portions (22A) are provided at locations that are not overlapped with the tabs (26, 28) when viewed in a lamination direction of the electrode body (25). [4] The battery cell according to any one of claims 1 to 3, wherein the conductive members (30, 32, 52, 54) are provided at locations that are not overlapped with the electrode body (25) when viewed in a lamination direction of the electrode body (25). [5] A battery cell according to any one of claims 1 to 4, wherein at least a portion of each conductive member (30, 32, 52, 54) is disposed at a location overlapping with a corresponding tab when viewed in a lamination direction of the electrode body (25). [6] A battery cell according to any one of claims 1 to 4, wherein an entirety of each tab is superimposed with a corresponding conductive element (30, 32, 52, 54) when viewed in a lamination direction of the electrode body (25). [7] Battery cell according to claim 2, wherein: each conductive element (30, 32, 52, 54) is connected to the metal layer at a connecting portion, and when viewed in a lamination direction of the electrode body (25), one side of the conductive member (30, 32, 52, 54) sandwiching the connecting portion is a tab-side contact portion capable of contacting a corresponding tab, and another side relative to the connecting portion is a laminate-side contact portion. [8] Battery cell according to claim 7, wherein the tab-side contact portion extends in a width direction of the tab by at least one width dimension of the tab. [9] Battery cell according to claim 8, wherein: each conductive element (30, 32, 52, 54) has a pair of bridging portions connecting between the tab-side contact portion and the laminate-side contact portion, and the bridging sections provided as a pair are each connected to the metal layer at the exposed sections. [10] A battery module in which a plurality of battery cells according to any one of claims 1 to 9 are accommodated in a lined-up state. [11] A battery module according to claim 10, wherein each tab is rotated in a direction away from a corresponding conductive element (30, 32, 52, 54).

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