power storage device

Abstract

The energy storage device includes individual modules and busbars. Each individual module comprises a first unit consisting of multiple cylindrical cells and a second unit consisting of multiple cylindrical cells. The busbars connect the first and second units to each other. The busbars include a positive busbar located at a first end along the length of the individual module and connected to the positive terminal of the first unit. The busbars also include a negative busbar located at the first end of the individual module and connected to the negative terminal of the second unit. Finally, the busbars include an intermediate busbar located at a second end along the length of the individual module, connecting the negative terminal of the first unit and the positive terminal of the second unit.

Description

Technical Field

[0001] The present disclosure relates to a power storage device. Background Art

[0002] Electric vehicles, hybrid vehicles and the like are each equipped with a battery pack composed of a battery module, a controller and the like. Further, the battery module installed in the battery pack, that is, the power storage device, includes a plurality of cylindrical cells as unit cells (refer to Patent Document 1).

[0003] Description of Related Art Patent Documents Patent Document 1: Japanese Unexamined Patent Application Publication No. 2024-618 Contents of the Invention

[0004] Technical Problem to be Solved by the Invention In some cases, a positive terminal may be provided at one end of the battery module, and a negative terminal may be provided at the other end of the battery module. However, providing the positive terminal and the negative terminal at both ends of the battery module is a factor that complicates the wiring of bus bars and cables. Therefore, there is a need to simplify the wiring of the battery module, that is, the power storage device.

[0005] Technical Solution for Solving the Technical Problem According to the present disclosure, a power storage device includes a cell assembly including a first cell unit composed of a plurality of cylindrical cells, and a second cell unit disposed adjacent to the first cell unit and composed of a plurality of cylindrical cells. The power storage device includes a bus bar group disposed opposite to the electrode surfaces of the cell assembly and interconnecting the first cell unit and the second cell unit. The bus bar group includes a positive electrode bus bar disposed at a first end portion in the length direction of the cell assembly and connected to the positive electrode of the first cell unit. The bus bar group includes a negative electrode bus bar disposed at the first end portion of the cell assembly and connected to the negative electrode of the second cell unit. The bus bar group includes an intermediate bus bar disposed at a second end portion in the length direction of the cell assembly and interconnecting the negative electrode of the first cell unit and the positive electrode of the second cell unit.

[0006] Effects of the Invention According to the present disclosure, the wiring of the power storage device can be simplified. Brief Description of the Drawings

[0007] Figure 1 This is a diagram illustrating an example of a vehicle.

[0008] Figure 2 This is a diagram illustrating an exemplary configuration of a battery pack.

[0009] Figure 3This is an exploded perspective view showing the battery module.

[0010] Figure 4 This is a diagram that briefly shows the battery module.

[0011] Figure 5 It is along Figure 3 Arrow A1 indicates a diagram of the individual components, insulation plates, and busbars.

[0012] Figure 6 It is along Figure 3 Arrow A1 indicates the direction of the busbar group diagram.

[0013] Figure 7 yes Figure 5 The enlarged view of range F7 is shown.

[0014] Figure 8 yes Figure 5 The enlarged view of range F8 is shown.

[0015] Figure 9 yes Figure 5 The enlarged view of range F9 is shown.

[0016] Figure 10 yes Figure 5 An enlarged view of the range F10 shown.

[0017] Figure 11 This is a diagram showing the connection status of individual units connected by a busbar group.

[0018] Figure 12 This is a diagram showing variations of individual components and busbar assemblies.

[0019] Figure 13 This is a diagram showing a variation of a busbar assembly.

[0020] Figure 14 yes Figure 12 The enlarged view of range F14 is shown.

[0021] Figure 15 yes Figure 12 The enlarged view of range F15 is shown.

[0022] Figure 16 yes Figure 12 The enlarged view of range F16 is shown.

[0023] Figure 17 yes Figure 12 The enlarged view of range F17 is shown. Detailed Implementation

[0024] The embodiments of the present invention will now be described in detail based on the accompanying drawings. It should be noted that in the following description, the same or substantially the same structures and elements will be labeled with the same symbols, and repeated descriptions will be omitted.

[0025] <Vehicles> Figure 1 This is a diagram showing an example of vehicle 10. Figure 1 The vehicle 10 shown includes a battery pack 14 assembled with an energy storage device as described in this embodiment of the present disclosure. Figure 1 As shown, the vehicle 10 includes an electric axle 13 consisting of an electric motor 11, a differential mechanism 12, etc., and a battery pack 14 located at the lower part of the vehicle body. The battery pack 14 is connected to the electric motor 11 of the electric axle 13 via an inverter 15. Furthermore, the battery pack 14 is connected to a cooling system 18 consisting of a water pump 16, a radiator 17, etc. Additionally, the differential mechanism 12 of the electric axle 13 is connected to the wheels 20 via axles 19.

[0026] <Battery Pack> Figure 2 This is a diagram showing an example of the structure of battery pack 14. (As shown...) Figure 2 As shown, the battery pack 14 includes a battery housing 21, multiple battery modules (energy storage devices) 22 and 23 housed within the battery housing 21, and a junction box 24 disposed within the battery housing 21. The junction box 24 is provided with a terminal block 25, high-voltage connectors 26 and 27, and an electronic control unit 28, etc. In addition, the inverter 15 is connected to the high-voltage connectors 26 and 27 of the junction box 24 via high-voltage cables 29 and 30.

[0027] The positive terminal plate 22a of battery module 22 is connected to the positive terminal connection portion 25a of terminal block 25 via module bus 31a, and the negative terminal plate 22b of battery module 22 is connected to the negative terminal connection portion 25b of terminal block 25 via module bus 31b. Similarly, the positive terminal plate 23a of battery module 23 is connected to the positive terminal connection portion 25a of terminal block 25 via module bus 32a, and the negative terminal plate 23b of battery module 23 is connected to the negative terminal connection portion 25b of terminal block 25 via module bus 32b.

[0028] Furthermore, in the illustrated example, two battery modules 22 and 23 are arranged in the battery pack 14, but this is not a limitation; the battery pack 14 may contain one battery module or more than three battery modules. Additionally, in the illustrated example, battery modules 22 and 23 are connected in parallel, but this is not a limitation; battery modules 22 and 23 may be connected in series.

[0029] The cooling system 18 includes a water pump 16 for pumping coolant and a radiator 17 as a heat exchanger. An outlet pipe 34 is connected to the outlet port 16a of the water pump 16, and an intake pipe 36 is connected to the intake port 16b of the water pump 16 via a connecting pipe 35 and the radiator 17. A branch of the outlet pipe 34, the outlet pipe 34a, is connected to a connector 37 of the battery module 22, and a branch of the outlet pipe 34b, the outlet pipe 34b, is connected to a connector 38 of the battery module 23. Furthermore, a branch of the intake pipe 36, the intake pipe 36a, is connected to a connector 39 of the battery module 22, and a branch of the intake pipe 36b, the intake pipe 36b, is connected to a connector 40 of the battery module 23.

[0030] <Battery Module> In the above description, the battery module is described by symbols 22 and 23, the positive terminal board is described by symbols 22a and 23a, and the negative terminal board is described by symbols 22b and 23b. In the following description, the battery module is described by symbol 50, the positive terminal board is described by symbol 50a, and the negative terminal board is described by symbol 50b.

[0031] Figure 3 This is an exploded perspective view showing the battery module 50. Because the battery module 50 has an elongated shape, Figure 3 The two ends of the battery module 50 and its vicinity are shown. Figure 4 This is a diagram that briefly shows the battery module 50. Figure 5 It is along Figure 3 Arrow A1 indicates the diagram of the individual component 56, the insulating plate 58, and the busbar assembly 59. Figure 6 It is along Figure 3 Arrow A1 indicates the direction of busbar group 59. Figure 7 yes Figure 5 The enlarged view of range F7 is shown. Figure 8 yes Figure 5 The enlarged view of range F8 is shown. Furthermore, in Figure 5 and Figure 6 In, with Figure 3 Similarly, the two ends and the surrounding areas of the individual component 56 and the bus group 59 are shown.

[0032] like Figure 3As shown, the battery module (energy storage device) 50 includes a housing 54 consisting of an upper cover 51, a lower cover 52, and a side cover 53. The housing 54 houses a single-cell assembly 56 composed of multiple cylindrical cells 55, and also houses an insulating plate 58 mounted on the electrode surface 57 at the lower end of the single-cell assembly 56. A busbar assembly 59 disposed between the insulating plate 58 and the lower cover 52 is housed within the housing 54. This busbar assembly 59 is disposed opposite to the electrode surface 57 of the single-cell assembly 56. Furthermore, the busbar assembly 59 includes multiple busbars 65, 66, 67, 81, 82, 83, and 84, which are constructed of metal plates such as aluminum alloy. Additionally, a positive terminal plate 50a is integrally disposed on the busbar 65, and a negative terminal plate 50b is integrally disposed on the busbar 66.

[0033] <Monomeric units and monomer groups> like Figure 4 As shown, the battery module 50 includes a single-cell assembly 56 housed within a housing 54. This single-cell assembly 56 includes a single-cell unit (first single-cell unit) 61 composed of multiple cylindrical cells 55 and a single-cell unit (second single-cell unit) 62 composed of multiple cylindrical cells 55. The single-cell units 61 and 62 are arranged adjacent to each other in the width direction D2 of the single-cell assembly 56. In other words, the single-cell units 61 and 62 are arranged parallel to each other.

[0034] like Figure 5 As shown, the monomer unit 61 of the monomer assembly 56 includes multiple monomer groups (first monomer group) 71 composed of multiple cylindrical monomers 55 and multiple monomer groups (second monomer group) 72 composed of multiple cylindrical monomers 55. Monomer groups 71 and 72 are alternately arranged in the longitudinal direction D1 of the monomer assembly 56. Similarly, the monomer unit 62 of the monomer assembly 56 includes multiple monomer groups (third monomer group) 73 composed of multiple cylindrical monomers 55 and multiple monomer groups (fourth monomer group) 74 composed of multiple cylindrical monomers 55. Monomer groups 73 and 74 are alternately arranged in the longitudinal direction D1 of the monomer assembly 56. Furthermore, a potting material (not shown) is injected into the gaps between the cylindrical monomers 55 disposed in the monomer assembly 56.

[0035] <Bus Group> like Figure 5As shown, the bus assembly 59 includes a positive bus 65 disposed at an end (first end) 56a of the individual assembly 56 along the length direction D1, a negative bus 66 disposed at an end 56a of the individual assembly 56 along the length direction D1, and an intermediate bus 67 disposed at an end (second end) 56b of the individual assembly 56 along the length direction D1. The positive bus 65 includes a plate portion 65a and a plurality of parallel rod portions 65b extending linearly from the plate portion 65a along the length direction D1. Similarly, the negative bus 66 includes a plate portion 66a and a plurality of parallel rod portions 66b extending linearly from the plate portion 66a along the length direction D1. Furthermore, the intermediate bus 67 includes a plate portion 67a and a plurality of parallel rod portions 67b extending linearly from the plate portion 67a along the length direction D1.

[0036] Bus group 59 includes multiple individual busbars 81 and multiple individual busbars 82 for connecting multiple cylindrical units 55 constituting unit 61 to each other. Specifically, bus group 59 includes multiple individual busbars (first busbars) 81 disposed between ends 56a and 56b of unit assembly 56. Furthermore, bus group 59 includes multiple individual busbars (second busbars) 82 disposed between ends 56a and 56b of unit assembly 56. Individual busbars 81 and 82 are alternately arranged in the longitudinal direction D1 of unit assembly 56.

[0037] Similarly, bus group 59 includes multiple individual busbars 83 and multiple individual busbars 84 for connecting multiple cylindrical units 55 constituting unit 62 to each other. That is, bus group 59 includes multiple individual busbars (third busbars) 83 disposed between ends 56a and 56b of unit assembly 56. In addition, bus group 59 includes multiple individual busbars (fourth busbars) 84 disposed between ends 56a and 56b of unit assembly 56. Individual busbars 83 and individual busbars 84 are alternately arranged in the longitudinal direction D1 of unit assembly 56.

[0038] like Figure 4 As shown, a separator 68 is provided between individual unit 61 and individual unit 62. That is, the separator 68 is provided between the positive bus 65 and the negative bus 66, between individual bus 81 and individual bus 83, and between individual bus 82 and individual bus 84. By providing the separator 68 in this way, short circuits between the positive bus 65 and the negative bus 66, between individual bus 81 and individual bus 83, and between individual bus 82 and individual bus 84 can be prevented.

[0039] like Figure 6As shown, the individual busbar 81 includes a plurality of parallel rods (first parallel rods) 81a arranged parallel to each other, and a plurality of connecting rods (first connecting rods) 81b connecting the plurality of parallel rods 81a to each other. The parallel rods 81a extend linearly in the length direction D1 of the individual assembly 56, and the connecting rods 81b extend linearly in a direction inclined relative to the length direction D1. Figure 7 As shown, the connecting rod portion 81b extends substantially parallel to the dashed line L1, which connects the centers of adjacent cylindrical monomers 55 in the width direction D2 of the monomer assembly 56. Furthermore, as described later, the parallel rod portion 81a of the monomer busbar 81 is connected to the positive terminal of the monomer group 71 and to the negative terminal of the monomer group 72.

[0040] The individual busbar 82 includes a plurality of parallel rods (second parallel rods) 82a arranged parallel to each other, and a plurality of connecting rods (second connecting rods) 82b connecting the plurality of parallel rods 82a to each other. The parallel rods 82a extend linearly in the longitudinal direction D1 of the individual assembly 56, and the connecting rods 82b extend linearly in a direction inclined relative to the longitudinal direction D1. Figure 7 As shown, the connecting rod portion 82b extends substantially parallel to the dashed line L2, which connects the centers of adjacent cylindrical monomers 55 in the width direction D2 of the monomer assembly 56. Furthermore, as described later, the parallel rod portion 82a of the monomer busbar 82 is connected to the positive terminal of the monomer group 72 and to the negative terminal of the monomer group 71.

[0041] The individual busbar 83 includes a plurality of parallel rods (third parallel rods) 83a arranged parallel to each other, and a plurality of connecting rods (third connecting rods) 83b connecting the plurality of parallel rods 83a to each other. The parallel rods 83a extend linearly in the longitudinal direction D1 of the individual assembly 56, and the connecting rods 83b extend linearly in a direction inclined relative to the longitudinal direction D1. Figure 8 As shown, the connecting rod portion 83b extends substantially parallel to the dashed line L3, which connects the centers of adjacent cylindrical monomers 55 in the width direction D2 of the monomer assembly 56. Furthermore, as described later, the parallel rod portion 83a of the monomer busbar 83 is connected to the positive terminal of the monomer group 73 and to the negative terminal of the monomer group 74.

[0042] The individual busbar 84 includes a plurality of parallel rods (fourth parallel rods) 84a arranged parallel to each other, and a plurality of connecting rods (fourth connecting rods) 84b connecting the plurality of parallel rods 84a to each other. The parallel rods 84a extend linearly in the length direction D1 of the individual assembly 56, and the connecting rods 84b extend linearly in a direction inclined relative to the length direction D1. Figure 8As shown, the connecting rod portion 84b extends substantially parallel to the dashed line L4, which connects the centers of adjacent cylindrical monomers 55 in the width direction D2 of the monomer assembly 56. Furthermore, as described later, the parallel rod portion 84a of the monomer busbar 84 is connected to the positive terminal of the monomer group 74 and to the negative terminal of the monomer group 73.

[0043] <Connection structure of cylindrical unit (enlarged view)> like Figure 7 As shown in the enlarged portion, each cylindrical monomer 55 constituting monomer groups 71, 72, 73 and 74 includes a positive terminal 55a disposed at the center of the monomer end face and an annular negative terminal 55b disposed around the positive terminal 55a.

[0044] The structure of the cylindrical unit 55 connected by unit busbars 81 and 82 will be described below. Figure 7 As shown, each parallel rod portion 81a of the unit busbar 81 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the two cylindrical units 55 constituting the unit group 71, and to the negative terminal (negative electrode) 55b of the two cylindrical units 55 constituting the unit group 72. Furthermore, each parallel rod portion 82a of the unit busbar 82 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the two cylindrical units 55 constituting the unit group 72, and to the negative terminal (negative electrode) 55b of the two cylindrical units 55 constituting the unit group 71.

[0045] The structure of the cylindrical unit 55 connected by unit busbars 83 and 84 will be described below. Figure 8 As shown, each parallel rod portion 83a of the unit bus 83 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the two cylindrical units 55 constituting the unit group 73, and to the negative terminal (negative electrode) 55b of the two cylindrical units 55 constituting the unit group 74. Furthermore, each parallel rod portion 84a of the unit bus 84 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the two cylindrical units 55 constituting the unit group 74, and to the negative terminal (negative electrode) 55b of the two cylindrical units 55 constituting the unit group 73.

[0046] Figure 9 yes Figure 5 The image shown is an enlarged view of range F9. The following will refer to... Figure 9 The structure of the cylindrical cell 55 connected by the positive busbar 65 and the negative busbar 66 is described. For example... Figure 9As shown, each parallel rod portion 65b of the positive busbar 65 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the two cylindrical cells 55 constituting the cell group 71. Furthermore, each parallel rod portion 66b of the negative busbar 66 is connected via a connecting line 85 to the negative terminal (negative electrode) 55b of the two cylindrical cells 55 constituting the cell group 74.

[0047] Figure 10 yes Figure 5 The image shown is an enlarged view of range F10. The following will refer to... Figure 10 The structure of the cylindrical unit 55 connected by the intermediate busbar 67 is described below. For example... Figure 10 As shown, each parallel rod 67b of the intermediate busbar 67 is connected via a bonding line 85 to the negative terminal (negative pole) 55b of the two cylindrical monomers 55 constituting the monomer group 72, and to the positive terminal (positive pole) 55a of the two cylindrical monomers 55 constituting the monomer group 73.

[0048] <Connection structure of cylindrical unit (circuit diagram)> Figure 11 This diagram illustrates the connection status of individual units 71, 72, 73, and 74 connected by busbar assembly 59. (See diagram for example.) Figure 11 As shown, a positive busbar 65 located at end 56a of the monomer assembly 56 is connected to the positive electrode of the cylindrical monomer 55 constituting the monomer group 71. Furthermore, a negative busbar 66 located at end 56a of the monomer assembly 56 is connected to the negative electrode of the cylindrical monomer 55 constituting the monomer group 74. Additionally, an intermediate busbar 67 located at end 56b of the monomer assembly 56 is connected to the negative electrode of the cylindrical monomer 55 constituting the monomer group 72 and the positive electrode of the cylindrical monomer 55 constituting the monomer group 73.

[0049] To interconnect the plurality of cylindrical cells 55 constituting the single-cell unit 61, a single-cell busbar 81 and a single-cell busbar 82 are provided between ends 56a and 56b of the single-cell assembly 56. The single-cell busbar 81 is connected to the positive terminal of the cylindrical cell 55 constituting the single-cell group 71 and the negative terminal of the cylindrical cell 55 constituting the single-cell group 72. Furthermore, the single-cell busbar 82 is connected to the positive terminal of the cylindrical cell 55 constituting the single-cell group 72 and the negative terminal of the cylindrical cell 55 constituting the single-cell group 71.

[0050] To connect the plurality of cylindrical cells 55 constituting the single-cell unit 62 to each other, a single-cell busbar 83 and a single-cell busbar 84 are provided between ends 56a and 56b of the single-cell assembly 56. The single-cell busbar 83 is connected to the positive terminal of the cylindrical cell 55 constituting the single-cell group 73 and the negative terminal of the cylindrical cell 55 constituting the single-cell group 74. Furthermore, the single-cell busbar 84 is connected to the positive terminal of the cylindrical cell 55 constituting the single-cell group 74 and the negative terminal of the cylindrical cell 55 constituting the single-cell group 73.

[0051] That is, the plurality of cylindrical monomers 55 constituting monomer group 71 are connected in parallel with each other, and the plurality of cylindrical monomers 55 constituting monomer group 72 are connected in parallel with each other. Similarly, the plurality of cylindrical monomers 55 constituting monomer group 73 are connected in parallel with each other, and the plurality of cylindrical monomers 55 constituting monomer group 74 are connected in parallel with each other. In addition, monomer groups 71, 72, 73 and 74 are connected in series with each other.

[0052] like Figure 11 As shown, an intermediate busbar 67 is provided at the end 56b of the single-cell assembly 56, through which the negative electrode of the single-cell unit 61 and the positive electrode of the single-cell unit 62 are interconnected. Therefore, the positive electrode of the single-cell unit 61 and the negative electrode of the single-cell unit 62 can be concentrated at the end 56a of the single-cell assembly 56, and the positive electrode busbar 65 and the negative electrode busbar 66 can also be concentrated at the end 56a of the single-cell assembly 56. That is, since the positive terminal plate 50a and the negative terminal plate 50b of the battery module 50 can be concentrated in one direction along the length of the battery module 50, the wiring of the battery module 50 can be simplified.

[0053] That is, when the positive terminal board 50a is installed in one direction along the length of the battery module 50, and the negative terminal board 50b is installed in another direction along the length of the battery module 50, the wiring consisting of busbars, cables, etc. becomes longer. Conversely, when the positive terminal board 50a and the negative terminal board 50b are concentrated in one direction along the length of the battery module 50, the wiring consisting of busbars, cables, etc. can be shortened.

[0054] <Bus Shape> like Figure 6As shown, the bus group 59 includes multiple individual busbars 81, 82, 83, and 84. All individual busbars 81 are identical in shape, and all individual busbars 82 are identical in shape. Furthermore, all individual busbars 83 and 84 are identical in shape. As described above, by forming the multiple individual busbars 81, 82, 83, and 84 with identical shapes, the number of busbar types constituting the bus group 59 can be reduced. This allows for control of the cost of the battery module 50 and the battery pack 14.

[0055] In the illustrated example, all multiple individual busbars 81 are formed with the same shape, all multiple individual busbars 82 are formed with the same shape, all multiple individual busbars 83 are formed with the same shape, and all multiple individual busbars 84 are formed with the same shape, but the invention is not limited thereto. For example, at least any two of the multiple individual busbars 81 can be formed with the same shape, at least any two of the multiple individual busbars 82 can be formed with the same shape, at least any two of the multiple individual busbars 83 can be formed with the same shape, and at least any two of the multiple individual busbars 84 can be formed with the same shape. Even in this case, the number of busbars constituting the busbar group 59 can be reduced, and the cost of the battery pack 14 can be controlled.

[0056] like Figure 6 As shown, individual busbars 81 and 83 have the same shape. As described above, by forming individual busbars 81 and 83 with the same shape, the number of busbar types constituting busbar group 59 can be reduced. Furthermore, individual busbars 82 and 84 have the same shape. As described above, by forming individual busbars 82 and 84 with the same shape, the number of busbar types constituting busbar group 59 can be reduced. Therefore, the cost of battery module 50 and battery pack 14 can be controlled.

[0057] like Figure 6 As shown, the positive bus 65 and the negative bus 66 have the same shape. As described above, by forming the positive bus 65 and the negative bus 66 with the same shape, the number of bus types constituting the bus group 59 can be reduced. Therefore, the cost of the battery module 50 and the battery pack 14 can be controlled. Figure 3In the example shown, the positive electrode component 86, consisting of the positive busbar 65 and the positive terminal plate 50a connected thereto, and the negative electrode component 87, consisting of the negative busbar 66 and the negative terminal plate 50b connected thereto, have the same shape, but are not limited thereto. That is, the positive busbar 65 and the negative busbar 66 can have the same shape, while the positive terminal plate 50a and the negative terminal plate 50b can have different shapes.

[0058] like Figure 7 As indicated by the middle arrow X1, the cylindrical cells 55 adjacent to each other in the width direction D2 of the cell assembly 56 are staggered in the length direction D1 of the cell assembly 56. This allows multiple cylindrical cells 55 to be effectively housed within the housing 54, increasing the energy storage capacity of the battery module 50. Furthermore, since multiple cylindrical cells 55 can be arranged adjacent to each other, the connection operation of the cylindrical cells 55 to the busbars 65-67 and 81-84 via the connecting lines 85 becomes easier.

[0059] Furthermore, since the adjacent cylindrical units 55, 55 in the width direction D2 are staggered in the length direction D1, the connecting rods 81b, 82b, 83b, 84b of the unit busbars 81, 82, 83, 84 extend in a direction inclined relative to the length direction D1. Therefore, the unit busbars 81, 82, 83, 84 can be appropriately positioned relative to the electrode surface 57 of the unit assembly 56 without causing interference between the terminals 55a, 55b of the cylindrical units 55 and the unit busbars 81, 82, 83, 84.

[0060] <Variation Example> Figure 12 This is a diagram showing variations of individual components and busbar assemblies. Figure 13 This is a diagram showing a variation of a busbar assembly. Figure 14 yes Figure 12 The enlarged view of range F14 is shown. Figure 15 yes Figure 12 The enlarged view of range F15 is shown. Figure 16 yes Figure 12 The enlarged view of range F16 is shown. Figure 17 yes Figure 12 An enlarged view of range F17 is shown. Furthermore, Figure 12 and Figure 13 The above is shown Figure 5 and Figure 6 The same location. Furthermore, in Figure 12 In, with Figure 5 Components and parts that are identical to those shown are represented by the same symbols, and their descriptions are omitted.

[0061] like Figure 12As shown, the individual component 90 includes a single unit (first single unit) 101 composed of multiple cylindrical units 55, and a single unit (second single unit) 102 composed of multiple cylindrical units 55. Single units 101 and 102 are arranged adjacent to each other in the width direction D2 of the individual component 90. Single unit 101 includes multiple groups of single units (first single units) 111 composed of multiple cylindrical units 55, and multiple groups of single units (second single units) 112 composed of multiple cylindrical units 55. Single units 111 and 112 are alternately arranged in the length direction D1 of the individual component 90. Similarly, the single unit 101 of the individual component 90 includes multiple groups of single units (third single units) 113 composed of multiple cylindrical units 55, and multiple groups of single units (fourth single units) 114 composed of multiple cylindrical units 55. Single units 113 and 114 are alternately arranged in the length direction D1 of the individual component 90.

[0062] like Figure 12 As shown, the bus group 92 opposite to the electrode surface 91 of the single-cell assembly 90 includes a positive bus 105 disposed at an end (first end) 90a of the single-cell assembly 90 in the length direction D1, a negative bus 106 disposed at an end 90a of the single-cell assembly 90 in the length direction D1, and an intermediate bus 107 disposed at an end (second end) 90b of the single-cell assembly 90 in the length direction D1. The positive bus 105 includes a plate portion 105a and a plurality of parallel rod portions 105b extending linearly from the plate portion 105a in the length direction D1. The negative bus 106 includes a plate portion 106a and a plurality of parallel rod portions 106b extending linearly from the plate portion 106a in the length direction D1. The intermediate bus 107 includes a plate portion 107a and a plurality of parallel rod portions 107b extending linearly from the plate portion 107a in the length direction D1.

[0063] Bus group 92 includes multiple individual busbars 121 and multiple individual busbars 122 for connecting multiple cylindrical units 55 constituting unit 101 to each other. Specifically, bus group 92 includes multiple individual busbars (first busbars) 121 disposed between ends 90a and 90b of unit assembly 90. Furthermore, bus group 92 includes multiple individual busbars (second busbars) 122 disposed between ends 90a and 90b of unit assembly 90. Individual busbars 121 and 122 are alternately arranged in the longitudinal direction D1 of unit assembly 90.

[0064] Similarly, bus group 92 includes multiple individual busbars 123 and multiple individual busbars 124 for connecting multiple cylindrical units 55 constituting unit 102 to each other. That is, bus group 92 includes multiple individual busbars (third busbars) 123 disposed between ends 90a and 90b of unit assembly 90. In addition, bus group 92 includes multiple individual busbars (fourth busbars) 124 disposed between ends 90a and 90b of unit assembly 90. Individual busbars 123 and individual busbars 124 are alternately arranged in the longitudinal direction D1 of unit assembly 90.

[0065] like Figure 13 As shown, the individual busbar 121 includes a plurality of parallel rods (first parallel rods) 121a arranged parallel to each other, and a plurality of connecting rods (first connecting rods) 121b connecting the plurality of parallel rods 121a to each other. The parallel rods 121a extend linearly in the length direction D1 of the individual assembly 90, and the connecting rods 121b extend in a curved manner in a direction inclined relative to the length direction D1. Figure 14 As shown, the connecting rod portion 121b extends in a gently curved, approximately S-shaped shape along the outer periphery of the cylindrical units 55 that are adjacent to each other in the width direction D2 of the unit assembly 90.

[0066] The individual busbar 122 includes a plurality of parallel rods (second parallel rods) 122a arranged parallel to each other, and a plurality of connecting rods (second connecting rods) 122b connecting the plurality of parallel rods 122a to each other. The parallel rods 122a extend linearly in the longitudinal direction D1 of the individual assembly 90, and the connecting rods 122b extend linearly in a direction inclined relative to the longitudinal direction D1. Figure 14 As shown, the connecting rod portion 122b extends in a gently curved, approximately S-shaped shape along the outer periphery of the cylindrical units 55 that are adjacent to each other in the width direction D2 of the unit assembly 90.

[0067] The individual busbar 123 includes a plurality of parallel rods (third parallel rods) 123a arranged parallel to each other, and a plurality of connecting rods (third connecting rods) 123b connecting the plurality of parallel rods 123a to each other. The parallel rods 123a extend linearly in the length direction D1 of the individual assembly 90, and the connecting rods 123b extend in a curved manner in a direction inclined relative to the length direction D1. Figure 15 As shown, the connecting rod portion 123b extends in a gently curved, approximately S-shaped shape along the outer periphery of the cylindrical units 55 that are adjacent to each other in the width direction D2 of the unit assembly 90.

[0068] The individual busbar 124 includes a plurality of parallel rods (fourth parallel rods) 124a arranged parallel to each other, and a plurality of connecting rods (fourth connecting rods) 124b connecting the plurality of parallel rods 124a to each other. The parallel rods 124a extend linearly in the longitudinal direction D1 of the individual assembly 90, and the connecting rods 124b extend linearly in a direction inclined relative to the longitudinal direction D1. Figure 15 As shown, the connecting rod portion 124b extends in a gently curved, approximately S-shaped shape along the outer periphery of the cylindrical units 55 that are adjacent to each other in the width direction D2 of the unit assembly 90.

[0069] <Connection structure of cylindrical unit (enlarged view)> The structure of the cylindrical unit 55 connected by unit busbars 121 and 122 will be described below. Figure 14 As shown, each parallel rod portion 121a of the unit bus 121 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the three cylindrical units 55 constituting unit group 111, and to the negative terminal (negative electrode) 55b of the three cylindrical units 55 constituting unit group 112. Furthermore, each parallel rod portion 122a of the unit bus 122 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the three cylindrical units 55 constituting unit group 112, and to the negative terminal (negative electrode) 55b of the three cylindrical units 55 constituting unit group 111.

[0070] The structure of cylindrical unit 55 connected by unit busbars 123 and 124 will be described below. Figure 15 As shown, each parallel rod portion 123a of the unit bus 123 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the three cylindrical units 55 constituting the unit group 113, and to the negative terminal (negative electrode) 55b of the three cylindrical units 55 constituting the unit group 114. Furthermore, each parallel rod portion 124a of the unit bus 124 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the three cylindrical units 55 constituting the unit group 114, and to the negative terminal (negative electrode) 55b of the three cylindrical units 55 constituting the unit group 113.

[0071] The structure of the cylindrical cell 55 connected by the positive busbar 105 and the negative busbar 106 will be described below. Figure 16 As shown, each parallel rod portion 105b of the positive busbar 105 is connected via a connecting line 85 to the positive terminal (positive electrode) 55a of the three cylindrical cells 55 constituting the cell group 111. Furthermore, each parallel rod portion 106b of the negative busbar 106 is connected via a connecting line 85 to the negative terminal (negative electrode) 55b of the three cylindrical cells 55 constituting the cell group 114.

[0072] The structure of the cylindrical unit 55 connected by the intermediate busbar 107 will be described below. Figure 17 As shown, each parallel rod portion 107b of the intermediate busbar 107 is connected via a connecting line 85 to the negative terminal (negative pole) 55b of the three cylindrical cells 55 constituting the cell group 112, and to the positive terminal (positive pole) 55a of the three cylindrical cells 55 constituting the cell group 113.

[0073] like Figure 12 As shown, an intermediate busbar 107 is provided at the end 90b of the single-cell assembly 90, through which the negative electrode of the single-cell unit 101 and the positive electrode of the single-cell unit 102 are interconnected. Therefore, the positive electrode of the single-cell unit 101 and the negative electrode of the single-cell unit 102 can be concentrated at the end 90a of the single-cell assembly 90, and the positive electrode busbar 105 and the negative electrode busbar 106 can also be concentrated at the end 90a of the single-cell assembly 90. That is, since the positive terminal plate 50a and the negative terminal plate 50b of the battery module 50 can be concentrated in one direction along the length of the battery module 50, the wiring of the battery module 50 can be simplified.

[0074] <Bus Shape> like Figure 13 As shown, all individual busbars 121 are identical in shape, and all individual busbars 122 are identical in shape. Furthermore, all individual busbars 123 and 124 are identical in shape. Additionally, individual busbars 121 and 123 are identical in shape, and individual busbars 122 and 124 are identical in shape. Furthermore, the positive busbar 105 and negative busbar 106 are identical in shape. Therefore, by reducing the number of busbar types constituting the busbar group 92, the cost of the battery module 50 and the battery pack 14 can be controlled.

[0075] Furthermore, since the adjacent cylindrical units 55, 55 in the width direction D2 are staggered in the length direction D1, the connecting rods 121b, 122b, 123b, and 124b of the unit busbars 121, 122, 123, and 124 extend in a direction inclined relative to the length direction D1. Therefore, the unit busbars 121, 122, 123, and 124 can be appropriately positioned relative to the electrode surface 91 of the unit assembly 90 without causing interference between the terminals 55a, 55b of the cylindrical units 55 and the unit busbars 121, 122, 123, and 124.

[0076] <Other variations> This invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from its spirit. In the illustrated example, the battery pack 14 is installed in an electric vehicle, but it is not limited thereto; the battery pack 14 can also be used in other devices. Furthermore, as the cylindrical cell 55, not only batteries such as lithium-ion batteries can be used, but also energy storage cells such as capacitors can be used.

[0077] In the illustrated example, the positive bus 65 (105) and the negative bus 66 (106) have the same shape, but are not limited thereto; the shapes of the positive bus 65 (105) and the negative bus 66 (106) may be different from each other. Furthermore, in the illustrated example, the individual bus 81 (121) and the individual bus 83 (123) have the same shape, but are not limited thereto; the shapes of the individual bus 81 (121) and the individual bus 83 (123) may be different from each other. Furthermore, in the illustrated example, the individual bus 82 (122) and the individual bus 84 (124) have the same shape, but are not limited thereto; the shapes of the individual bus 82 (122) and the individual bus 84 (124) may be different from each other.

[0078] Symbol Explanation 22, 23… Battery module (energy storage device), 50… Battery module (energy storage device), 55… Cylindrical cell, 55a… Positive terminal (positive electrode), 55b… Negative terminal (negative electrode), 56… Cell assembly, 56a… End (first end), 56b… End (second end), 57… Electrode surface, 59… Busbar assembly, 61… Cell unit (first cell unit), 62… Cell unit (second cell unit), 65… Positive busbar, 66… Negative busbar, 67… Intermediate busbar, 71… Cell group (first cell group), 72… Cell group (second cell group), 73… Cell Group (Third Unit Group), 74…Unit Group (Fourth Unit Group), 81…Unit Busbar (First Busbar), 81a…Parallel Rod Section (First Parallel Rod Section), 81b…Connecting Rod Section (First Connecting Rod Section), 82…Unit Busbar (Second Busbar), 82a…Parallel Rod Section (Second Parallel Rod Section), 82b…Connecting Rod Section (Second Connecting Rod Section), 83…Unit Busbar (Third Busbar), 83a…Parallel Rod Section (Third Parallel Rod Section), 83b…Connecting Rod Section (Third Connecting Rod Section), 84…Unit Busbar (Fourth Busbar), 84a…Parallel Rod Section (Fourth Parallel Rod Section), 84 b… Connecting rod (fourth connecting rod), 85… Connecting line, 90… Single unit assembly, 90a… End (first end), 90b… End (second end), 91… Electrode surface, 92… Busbar assembly, 101… Single unit (first single unit), 102… Single unit (second single unit), 105… Positive busbar, 106… Negative busbar, 107… Intermediate busbar, 111… Single unit group (first single unit group), 112… Single unit group (second single unit group), 113… Single unit group (third single unit group), 114… Single unit group (fourth single unit group), 121… Single unit busbar (first single unit group) ), 121a… parallel rod section (first parallel rod section), 121b… connecting rod section (first connecting rod section), 122… single busbar (second busbar), 122a… parallel rod section (second parallel rod section), 122b… connecting rod section (second connecting rod section), 123… single busbar (third busbar), 123a… parallel rod section (third parallel rod section), 123b… connecting rod section (third connecting rod section), 124… single busbar (fourth busbar), 124a… parallel rod section (fourth parallel rod section), 124b… connecting rod section (fourth connecting rod section), D1… length direction.

Claims

1. An energy storage device, comprising: - A single-unit assembly comprising a first single-unit cell composed of a plurality of cylindrical single-unit cells, and a second single-unit cell disposed adjacent to the first single-unit cell and composed of a plurality of cylindrical single-unit cells. and - A busbar assembly, disposed opposite to the electrode surface of the individual unit, and connecting the first and second individual units to each other. The busbar group includes: -- A positive busbar, which is disposed at a first end in the length direction of the single-cell assembly and connected to the positive electrode of the first single-cell unit; -- A negative busbar, disposed at the first end of the cell assembly and connected to the negative terminal of the second cell unit; and -- An intermediate busbar is disposed at the second end of the unit assembly along its length and connects the negative terminal of the first unit assembly and the positive terminal of the second unit assembly to each other.

2. The energy storage device according to claim 1, wherein... The first monomer unit includes a first monomer group composed of a plurality of the cylindrical monomers and a second monomer group composed of a plurality of the cylindrical monomers. The first monomer group and the second monomer group are alternately arranged along the length direction of the monomer assembly. The second monomer unit includes a third monomer group composed of multiple cylindrical monomers and a fourth monomer group composed of multiple cylindrical monomers. The third and fourth monomer groups are alternately arranged along the length of the monomer assembly. The positive busbar is connected to the positive electrode of the first monomer group. The negative electrode busbar is connected to the negative electrode of the fourth monomer group. The intermediate busbar is connected to the negative electrode of the second monomer group and the positive electrode of the third monomer group.

3. The energy storage device according to claim 1, wherein, The first monomer unit includes a first monomer group composed of a plurality of the cylindrical monomers and a second monomer group composed of a plurality of the cylindrical monomers. The first monomer group and the second monomer group are alternately arranged along the length direction of the monomer assembly. The second monomer unit includes a third monomer group composed of multiple cylindrical monomers and a fourth monomer group composed of multiple cylindrical monomers. The third and fourth monomer groups are alternately arranged along the length of the monomer assembly. The busbar group includes: Multiple first busbars are disposed between the first end and the second end of the single-cell assembly, and connect the positive electrode of the first single-cell group and the negative electrode of the second single-cell group to each other; Multiple second busbars are disposed between the first end and the second end of the single-cell assembly, and interconnect the positive terminal of the second single-cell group and the negative terminal of the first single-cell group. Multiple third buses are disposed between the first and second ends of the cell assembly, and interconnect the positive electrode of the third cell group and the negative electrode of the fourth cell group; and Multiple fourth buses are disposed between the first end and the second end of the single-cell assembly, and interconnect the positive electrode of the fourth single-cell group and the negative electrode of the third single-cell group.

4. The energy storage device according to claim 1, wherein, The positive bus and the negative bus have the same shape.

5. The energy storage device according to claim 3, wherein, The first bus and the third bus have the same shape.

6. The energy storage device according to claim 3, wherein, The second bus and the fourth bus have the same shape.

7. The energy storage device according to claim 3, wherein, The first busbar includes a plurality of first parallel rods arranged parallel to each other and connected by a bonding line, and a plurality of first connecting rods connecting the plurality of first parallel rods to each other. The second busbar includes a plurality of second parallel rods arranged parallel to each other and connected by a bonding line, and a plurality of second connecting rods connecting the plurality of second parallel rods to each other. The third busbar includes a plurality of parallel third rods connected by a bonding line, and a plurality of third connecting rods connecting the plurality of parallel third rods to each other. The fourth busbar includes a plurality of fourth parallel rods arranged in parallel to each other and connected by a bonding line, and a plurality of fourth connecting rods connecting the plurality of fourth parallel rods to each other.

8. The energy storage device according to claim 7, wherein, The first parallel rod portion, the second parallel rod portion, the third parallel rod portion, and the fourth parallel rod portion extend linearly along the length direction of the single component. The first connecting rod portion, the second connecting rod portion, the third connecting rod portion, and the fourth connecting rod portion extend in a straight line in a direction inclined relative to the length direction of the single component.

9. The energy storage device according to claim 7, wherein, The first parallel rod portion, the second parallel rod portion, the third parallel rod portion, and the fourth parallel rod portion extend linearly along the length direction of the single component. The first connecting rod portion, the second connecting rod portion, the third connecting rod portion, and the fourth connecting rod portion extend in a curved shape in a direction inclined relative to the length direction of the single component.

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