Electricity storage device

Abstract

The invention relates to a power storage device. A power storage device includes: a first power storage cell; a second power storage cell; and a wiring board. The wiring board includes a substrate and a plurality of conductor members disposed on a vertical upper surface of the substrate. The plurality of conductor members includes a first conductor member and a second conductor member. The first power storage cell includes, on a vertical lower surface thereof, a first electrode terminal connected to the first conductor member. The second power storage cell includes, on a vertical lower surface thereof, a second electrode terminal connected to the second conductor member. At least one of a convex portion, a concave portion, and a through hole is provided in a portion of the substrate between the first electrode terminal and the second electrode terminal.

Description

Energy storage device

[0001] Cross-references to related applications

[0002] This non-provisional application is based on Japanese Patent Application No. 2024-190805, filed with the Japan Patent Office on October 30, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an energy storage device comprising multiple energy storage cells. Background Technology

[0004] Chinese Patent Publication No. 116686151 discloses an energy storage device comprising a plurality of energy storage cells fixed in a housing (receiving cavity). The electrode terminals of each energy storage cell are positioned facing the bottom wall of the housing. Summary of the Invention

[0005] In the energy storage device described in Chinese Patent Publication No. 116686151, water generated in the casing due to condensation or the like may cause a short circuit between the electrode terminals of adjacent energy storage cells.

[0006] This disclosure has been made to address the aforementioned problems, and the purpose of this disclosure is to provide an energy storage device in which short circuits are unlikely to occur between the electrode terminals of adjacent energy storage cells.

[0007] According to this disclosure, an energy storage device as described below is provided.

[0008] (Clause 1) The energy storage device includes: a first energy storage cell; a second energy storage cell; and a wiring board. The wiring board includes a substrate and a plurality of conductor members disposed on a vertical upper surface of the substrate. The plurality of conductor members includes a first conductor member and a second conductor member. The first energy storage cell includes a first electrode terminal connected to the first conductor member on its vertical lower surface. The second energy storage cell includes a second electrode terminal connected to the second conductor member on its vertical lower surface. At least one of a protrusion, a recess, and a through hole is provided in a portion of the substrate between the first electrode terminal and the second electrode terminal.

[0009] According to the above structure, even if water is generated in one of the adjacent battery cells (the first battery cell and the second battery cell), the diffusion of water to the other battery cell is suppressed. This makes it unlikely that a short circuit will occur between the electrode terminals of adjacent battery cells.

[0010] (Clause 2) In the energy storage device according to Clause 1, one or more through holes are formed in the portion of the substrate between the first electrode terminal and the second electrode terminal.

[0011] One or more through holes exist between the electrodes of adjacent battery cells, making it less likely that a short circuit will occur between the electrode terminals due to water.

[0012] (Clause 3) In the energy storage device according to Clause 2, the substrate includes: one or more first portions located at the edge portions of the one or more through holes; and a second portion having a higher degree of hydrophobicity than the first portions.

[0013] Because the first part is located at the edge of the through hole, water between the electrodes is more easily guided into the through hole.

[0014] (Clause 4) In the energy storage device according to Clause 2 or 3, the substrate includes: a first inclined portion that slopes downward from a first electrode terminal toward one or more through holes; and a second inclined portion that slopes downward from a second electrode terminal toward one or more through holes.

[0015] Water between the electrodes can be more easily guided into the through hole through the first and second inclined sections.

[0016] (Clause 5) In any one of Clauses 2 to 4, a recess is formed in the portion of the substrate between the first electrode terminal and the second electrode terminal, and the one or more through holes are formed in the recess.

[0017] Based on the above structure, the presence of recesses and through holes between the electrodes of adjacent battery cells makes it unlikely that a short circuit between the electrode terminals will occur due to water.

[0018] (Clause 6) In any one of Clauses 2 to 5, the energy storage device includes an exhaust path through which gas discharged from each of the first and second energy storage cells flows. One or more through-holes communicate with the exhaust path.

[0019] Based on the above structure, water that falls into the through hole is more easily discharged along with the gas.

[0020] (Clause 7) In the energy storage device described in Clause 6, the water-absorbing component is disposed between one or more through holes and the venting path.

[0021] The amount of water (liquid) falling into the exhaust path can be reduced by using a water-absorbing component.

[0022] (Clause 8) In the energy storage device according to Clause 6 or 7, each of the first and second energy storage cells further includes an explosion-proof valve on its vertically lower surface. A substrate is located on the vertically lower side of the explosion-proof valve of each of the first and second energy storage cells. An exhaust path is located on the vertically lower side of the substrate. A cooler is provided on the vertically lower surface of the substrate.

[0023] The gas around and from the explosion-proof valve is more easily cooled by the cooler.

[0024] (Clause 9) In any one of Clauses 1 to 8, one or more protrusions are formed in the portion of the substrate between the first electrode terminal and the second electrode terminal.

[0025] The presence of protrusions between the electrodes of adjacent battery cells makes it less likely that a short circuit will occur between the electrode terminals due to water. These protrusions can be applied together with recesses and / or through-holes.

[0026] As another embodiment, a vehicle may be provided, the vehicle including an energy storage device according to any one of clauses 1 to 9.

[0027] The foregoing and other objects, features, aspects and advantages of this disclosure will become more apparent when taken in conjunction with the accompanying drawings and the following detailed description of this disclosure. Attached Figure Description

[0028] Figure 1 is a diagram illustrating a vehicle including an energy storage device according to an embodiment of the present disclosure.

[0029] Figure 2 is a diagram illustrating a schematic configuration of an energy storage device according to an embodiment of the present disclosure.

[0030] Figure 3 is a view of the interior of the lower housing of the energy storage device of this embodiment, viewed from above.

[0031] Figure 4 is a diagram showing the lower housing of the energy storage device according to this embodiment in an empty state.

[0032] Figure 5 is a diagram illustrating an exemplary structure of a battery cell according to this embodiment.

[0033] Figure 6 is a diagram of each battery cell in the lower housing shown in Figure 3, viewed from below.

[0034] Figure 7 is a diagram illustrating an exemplary construction of the wiring board in the lower housing shown in Figure 3.

[0035] Figure 8 is an end view of the energy storage device taken along line VIII-VIII in Figure 3.

[0036] Figure 9 is an end view of the energy storage device taken along line IX-IX in Figure 3.

[0037] Figure 10 is an end view of the energy storage device taken along line XX in Figure 3.

[0038] Figure 11 is an end view of the energy storage device taken along line XI-XI in Figure 3.

[0039] Figure 12 is a diagram illustrating the cross-sectional structure of the wiring board shown in Figure 7.

[0040] Figure 13 is an end view of the energy storage device taken along line XIII-XIII in Figure 3.

[0041] Figure 14 is a diagram showing a variation of the recess shown in Figure 13.

[0042] Figure 15 is a diagram showing an example in which the recess shown in Figure 13 is not formed.

[0043] Figure 16 is a diagram showing an example in which multiple through holes as shown in Figure 13 are formed.

[0044] Figure 17 is a diagram showing a first modified example of the opening in the substrate shown in Figure 13.

[0045] Figure 18 is a diagram showing a second modified example of the opening in the substrate shown in Figure 13.

[0046] Figure 19 is a diagram showing an example in which the substrate shown in Figure 13 includes a cooler.

[0047] Figure 20 is a diagram showing an example of a substrate, in which the substrate shown in Figure 13 has a water-absorbing component.

[0048] Figure 21 is a diagram showing the first example, in which the through hole shown in Figure 13 is replaced by a protrusion.

[0049] Figure 22 is a diagram showing a second example, in which the through hole shown in Figure 13 is replaced by a protrusion.

[0050] Figure 23 is a diagram showing a modified example of the partition wall shown in Figure 4. Detailed Implementation

[0051] Embodiments of this disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding elements have the same assigned reference numerals and their descriptions will not be repeated. In each of the figures mentioned below, the X-axis, Y-axis, and Z-axis represent three axes orthogonal to each other. In the following description, the direction indicated by the arrows along each of the X-axis, Y-axis, and Z-axis is indicated by "+", and the opposite direction is indicated by "-".

[0052] Figure 1 is a diagram illustrating a vehicle including an energy storage device according to this embodiment. In Figure 1, the -X side corresponds to the front side of vehicle 1, and the +X side corresponds to the rear side of vehicle 1. The -Z side corresponds to the lower side (vertical lower side), and the +Z side corresponds to the upper side (vertical upper side).

[0053] Referring to Figure 1, vehicle 1 includes an energy storage device B. The energy storage device B can be used as a driving device and is generally referred to as a "battery pack". Vehicle 1 is configured to operate using electricity output from the energy storage device B. Vehicle 1 may include a motor that uses electricity supplied from the energy storage device B to rotate the drive wheels of vehicle 1. Vehicle 1 is, for example, a battery electric vehicle (BEV) that does not include an internal combustion engine. However, this disclosure is not limited to the above. Vehicle 1 may be a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) that includes an internal combustion engine, or it may be another type of electric vehicle (xEV).

[0054] The energy storage device B is, for example, placed under the floor of vehicle 1. The energy storage device B can be connected to the body of vehicle 1. The energy storage device B has supports 111 and 112 at its -X side end and supports 121 and 122 at its +X side end (see Figure 3 described below). Although not shown in Figure 1, the energy storage device B also has supports at both ends in the Y direction (e.g., supports 131 and 132 shown in Figure 3 described below). These supports are fastened to, for example, the floor member of vehicle 1, thereby connecting the energy storage device B to the body of vehicle 1 (e.g., the floor panel). At least a portion of the housing of the energy storage device B can serve as a structural member of vehicle 1. However, this disclosure is not limited to the above-described configuration. The energy storage device B can be placed on the floor of vehicle 1.

[0055] Figure 2 is a schematic diagram showing the structure of the energy storage device B. Referring to Figure 2, the energy storage device B includes a lower housing 100 (first housing component), an upper cover 110 (second housing component), and a shared panel 120 (third housing component), and these components serve as the housing of the energy storage device B. The lower housing 100 opens upward (on the +Z side) to accommodate multiple energy storage cells and various components associated with these energy storage cells. As will be described in detail below, the lower housing 100 accommodates energy storage cells, a cooler, a junction box (hereinafter referred to as "J / B"), etc. (see Figure 3). Each of the upper cover 110 and the shared panel 120 is fixed to the lower housing 100. The upper cover 110 is disposed above the lower housing 100 to serve as a cover for the lower housing 100. The shared panel 120 is disposed below the lower housing 100 (on the -Z side) to suppress impacts on the lower housing 100 caused by road surface interference. An exhaust path is formed between the lower housing 100 and the shared panel 120. The top cover 110 and the shared panel 120 correspond to the +Z side end and -Z side end of the energy storage device B, respectively. Essentially, the housing of the energy storage device B seals the space within it (the internal space). However, when a valve located within the housing is opened, the internal space communicates with the external space through this valve.

[0056] Figure 3 is a view of the interior of the lower housing 100 with the upper cover 110 removed, viewed from the +Z side. Referring to Figure 3, the lower housing 100 houses the battery stacks S1 to S6, the cooling device 20, the battery circuit cells 30, and the wiring board 200. Each of the battery stacks S1 to S6 includes a plurality of battery cells 10 arranged in the X direction. Details of the construction of each battery cell will be described below. The wiring board 200 has a wiring pattern for the battery stacks S1 to S6. The wiring board 200 can be used as a terminal box. The cooling device 20 includes ports 20A and 20B, pipes 21A and 21B extending in the Y direction, pipes 22A and 22B extending in the X direction, a plurality of coolers 22C extending in the Y direction, and a cooling pipe 23. These components are connected from the upstream side in the order of port 20A, pipe 21A, pipe 22A, cooling pipe 23, pipe 22B, pipe 21B, and port 20B. Pipes 22A and 22B are connected by a plurality of coolers 22C (cooling plates) arranged along the X direction. Coolers 22C are disposed between adjacent battery cells in each of the battery stacks S1 to S6. These adjacent battery cells are cooled by coolant flowing through flow paths formed in the coolers 22C. Coolers 22C have flow paths communicating with each of pipes 22A and 22B. Cooling pipe 23 is configured to cool battery circuit cells 30. A battery circuit cell 30 may be a single unit or may include multiple units.

[0057] Figure 4 is a diagram showing the lower housing 100 in an empty state (where the lower housing 100 does not contain anything).

[0058] Referring to Figure 4, the lower housing 100 has a bottom wall 101 (bottom portion) and a peripheral wall 102 (peripheral edge portion). The bottom wall 101 includes regions R1 to R5. The peripheral wall 102 includes side walls W1 to W4. Side walls W1, W2, W3, and W4 correspond to the -X side end, +X side end, -Y side end, and +Y side end of the lower housing 100, respectively. Side wall W2 includes side walls W21 to W23. Side walls W21 to W23 are located on the +X side of side walls W3 and W4, which extend in the X direction, and between side walls W21 and W23, side wall W22 is located furthest from the +X side. Brackets 121 and 122 (Figure 1) are respectively disposed on side walls W21 and W23. Exhaust valves 151 and 152 are disposed in side wall W22. Side wall W22 is connected to side walls W3 and W4 via side walls W21 and W23, respectively. The ends of sidewalls W3 and W4 on opposite sides (-X side) are connected to each other via sidewall W1 extending in the Y direction. Brackets 131 and 132 are respectively provided on sidewalls W3 and W4. Brackets 111 and 112 (FIG. 1) are provided on sidewall W1. Each sidewall W1 to W4 rises from the peripheral edge portion of the bottom wall 101 toward the +Z side. The internal space of the lower housing 100 is surrounded by sidewalls W1 to W4.

[0059] Partition walls 103 and 104 extending in the Y direction are disposed on the bottom wall 101. Each of partition walls 103 and 104 can be fastened to the bottom wall 101. Partition wall 104 is located on the +X side of partition wall 103. Each partition wall 103 and 104 rises from the bottom wall 101 towards the +Z side. Region R5 is a rectangular region disposed in the center of the lower housing 100 and is separated by partition walls 103 and 104. Region R5 is the region where the wiring board 200 and the battery stacks S1 to S6 (FIG. 3) are disposed. Region R5 is located between partition walls 103 and 104 (on the inner side of partition wall 103 and the inner side of partition wall 104). Partition walls 103 and 104 can exert a restraining force on the battery stacks S1 to S6 from both sides in the X direction. Each of partition walls 103 and 104 can be a transverse frame.

[0060] An opening h11 is formed at the location where each battery cell is positioned in region R5. Each of the plurality of openings h11 is configured to face the valve 13 (see Figure 5) of the battery cell 10 in the Z direction. The plurality of openings h11 are arranged in the X direction to form a row of openings h11. Hereinafter, the row of openings h11 arranged in the X direction will be referred to as the “first row of openings”. Six first rows of openings are formed in the bottom wall 101. An opening h12 is formed between two adjacent openings h11 in the Y direction. A plurality of openings h12 are arranged in the X direction to form a row of openings h12. Hereinafter, the row of openings h12 arranged in the X direction will be referred to as the “second row of openings”. Five second rows of openings are formed in the bottom wall 101. An opening h11 is, for example, an elongated hole extending through the bottom wall 101. An opening h12 is, for example, a circular hole extending through the bottom wall 101. However, the shape of each of the openings h11 and h12 can be appropriately modified. Each of the openings h11 and h12 is formed, for example, by stamping.

[0061] Regions R3 and R4 are respectively located on the -Y and +Y sides of region R5. Region R1 is located on the outer side (-X side) of partition wall 103. Region R2 is located on the outer side (+X side) of partition wall 104. Region R2 is the region where the battery circuit cell 30 (Figure 3) is located. Region R2 is located at the +X side end of the lower housing 100 and is separated by partition wall 104 and side wall W2.

[0062] In this embodiment, each of the bottom wall 101, the peripheral wall 102, and the partition walls 103 and 104 is made of metal. However, the materials can be appropriately changed. The bottom wall 101, the peripheral wall 102, and the partition walls 103 and 104 can be made of the same material, or they can be made of different materials. The bottom wall 101, the peripheral wall 102, and the partition walls 103 and 104 can be formed individually and joined together, or they can be integrally formed in a seamless manner.

[0063] Referring to Figures 3 and 4, ports 20A and 20B are located in sidewall W1. Ports 20A and 20B are substantially located at the center of sidewall W1 in the Y direction. Port 20B is located on the +Y side of port 20A. Pipes 21A and 21B are located in region R1. Pipes 22A and 22B are located in regions R3 and R4, respectively. Each of pipes 21A, 21B, 22A, and 22B is arranged to cool the peripheral edge portion of the energy storage device B (regions R1, R3, and R4). Cooling pipe 23 is located in region R2. Multiple coolers 22C are located in region R5.

[0064] Coolant supplied from port 20A to pipe 21A flows toward the -Y side in pipe 21A. Coolant flowing from pipe 21A into pipe 22A flows toward the +X side in pipe 22A towards cooling pipe 23, and also flows into the flow paths of multiple coolers 22C. Coolant flowing from pipe 22A into cooler 22C flows toward pipe 22B toward the +Y side, simultaneously cooling the battery stacks S1 to S6. Coolant flowing from pipe 22A into cooling pipe 23 flows toward pipe 22B toward the +Y side, simultaneously cooling the battery circuit cells 30. Coolant flowing from cooler 22C or cooling pipe 23 into pipe 22B flows toward pipe 21B toward the -X side in pipe 22B. Thereafter, coolant flows toward the -Y side in pipe 21B and exits from port 20B.

[0065] As described above, cooling device 20 is configured to cool the energy storage device B, which has a high temperature. However, when the energy storage device B has a low temperature due to weather conditions, location (e.g., a cold climate zone), the coolant can raise the temperature of the energy storage device B. The coolant can be circulated by a pump (not shown) connected to ports 20A and 20B. Vehicle 1 (FIG. 1) may include devices for regulating the temperature of the coolant (such as a heat exchanger, refrigeration unit, or heater). The coolant can be a liquid (e.g., water, oil, or antifreeze solution) or a gas (e.g., carbon dioxide gas).

[0066] In this embodiment, the wiring board 200 is disposed on the +Z side of the bottom wall 101, and further, the battery stacks S1 to S6 are disposed on the +Z side of the wiring board 200.

[0067] Figure 5 is a diagram illustrating an exemplary construction of a single cell constituting each of the energy storage stacks S1 to S6. Referring to Figure 5, the energy storage cell 10 includes a housing 10a and an electrode assembly 10b housed within the housing 10a. The housing 10a is a prismatic housing having a cuboid shape. The electrode assembly 10b may include one or more wound bodies (e.g., two wound bodies). For example, each of the wound bodies has a structure in which a positive electrode and a negative electrode are wound with a separator between them. Each of the positive and negative electrode includes an electrode foil and an active material layer. The energy storage cell 10 is, for example, a secondary battery, such as a lithium-ion battery, a nickel-metal hydride battery, or a sodium-ion battery. In this embodiment, a liquid lithium-ion battery is used as the energy storage cell 10. In addition to the electrode assembly 10b, an electrolyte solution is housed within the housing 10a. The electrolyte solution includes, for example, an organic solvent and a lithium salt. Examples of lithium-ion batteries include LFP batteries, which use lithium iron phosphate as the positive electrode active material, and ternary batteries, which use NMC (nickel manganese cobalt) as the positive electrode active material. The types of secondary batteries are not limited to those described above and can include, for example, all-solid-state secondary batteries. Instead of a wound structure, a stacked structure can be used (e.g., a stack in which the positive and negative electrode sheets are stacked with separators between them).

[0068] Electrode terminals 11 and 12, and valve 13, are disposed on a surface F10 of housing 10a. Surface F10 corresponds to an end face of the battery cell 10 in the height direction. Valve 13 serves as an explosion-proof valve. Housing 10a is substantially kept sealed. However, when the pressure in housing 10a exceeds a first reference value, valve 13 opens to reduce the pressure in housing 10a. Electrode terminals 11 and 12 are electrically connected to the positive and negative electrode plates of electrode assembly 10b, respectively, to serve as positive and negative terminals. The portion of housing 10a surrounding electrode terminals 11 and 12 (e.g., the portion indicated by the dashed line in FIG. 5) may be made of insulating material, and other portions may be made of metal. However, this disclosure is not limited to the foregoing. Housing 10a may be made of any material.

[0069] In this embodiment, each of the energy storage stacks S1 to S6 shown in FIG. 3 is composed of a plurality of energy storage cells 10 arranged along the X direction. The energy storage cells included in the energy storage stacks S1 to S6 have the same structure (see FIG. 5). By using universal energy storage cells 10 to form the energy storage stacks S1 to S6, it is easier to manufacture the energy storage device B, which leads to a reduction in manufacturing costs. However, this disclosure is not limited to the above. Each energy storage stack may include multiple types of energy storage cells. The number of energy storage stacks can be appropriately varied. The number of energy storage stacks may be one or more.

[0070] Figure 6 is a diagram of the battery stacks S1 to S6 disposed in the lower housing 100 when viewed from the -Z side. Referring to Figure 6, each of the battery stacks S1 to S6 includes N battery cells 10. N is, for example, equal to or greater than 20 and equal to or less than 50. However, this disclosure is not limited to the above. N can be equal to or greater than 2 and less than 20, or it can be greater than 50. N (including the number of battery cells in a battery stack) can be arbitrarily set.

[0071] In each battery stack, individual battery cells 10 are disposed within the lower housing 100 such that their height aligns with the Z-direction, their width with the X-direction, and their length with the Y-direction. However, the N individual battery cells 10 are arranged such that the positional relationship between electrode terminals 11 (positive terminals) and electrode terminals 12 (negative terminals) is reversed every two individual battery cells 10. In each battery stack, two individual battery cells 10, each including an electrode terminal 11 facing the +Y side, and two individual battery cells 10, each including an electrode terminal 11 facing the -Y side, are alternately disposed in the X-direction.

[0072] Battery stack S1 has terminal rows T1 and T2 in the X direction. Battery stack S2 has terminal rows T3 and T4 in the X direction. Battery stack S3 has terminal rows T5 and T6 in the X direction. Battery stack S4 has terminal rows T7 and T8 in the X direction. Battery stack S5 has terminal rows T9 and T10 in the X direction. Battery stack S6 has terminal rows T11 and T12 in the X direction. In each terminal row, two electrode terminals 11 (positive terminals) and two electrode terminals 12 (negative terminals) are alternately arranged in the X direction. From the -Y side to the +Y side, terminal rows T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, and T12 are arranged in this order.

[0073] The energy storage stacks S1 to S6 comprise the same number of individual energy storage cells and are arranged such that the cells are aligned. A column (column in the Y direction) is thus formed by six energy storage cells 10 arranged in the Y direction. These columns are arranged along the X direction. The "6×N" energy storage cells 10 are arranged into a matrix having six columns in the Y direction and N rows in the X direction. In the following text, the first, second, ..., and Nth battery cells 10, starting from the -X side of the battery stack S1, will be referred to as "cell 1(1)", "cell 1(2)", ..., "cell 1(1(N)" respectively. The first, second, ..., and Nth battery cells 10, starting from the -X side of the battery stack S2, will be referred to as "cell 2(1)", "cell 2(2)", ..., "cell 2(N)" respectively. The first, second, ..., and Nth battery cells 10, starting from the -X side of the battery stack S3, will be referred to as "cell 3(1)", "cell 3(2)", ..., ... The first, second, ..., Nth battery cell 10 from the -X side of the battery stack S4 will be represented as "cell 4(1)", "cell 4(2)", ..., "cell 4(N)" respectively. The first, second, ..., Nth battery cell 10 from the -X side of the battery stack S5 will be represented as "cell 5(1)", "cell 5(2)", ..., "cell 5(N)" respectively. The first, second, ..., Nth battery cell 10 from the -X side of the battery stack S6 will be represented as "cell 6(1)", "cell 6(2)", ..., "cell 6(N)" respectively.

[0074] The individual energy storage cells included in the energy storage stacks S1 to S6 shown in FIG. 6 are electrically connected to each other via a wiring pattern of a wiring board 200. The wiring board 200 has, for example, the wiring pattern shown in FIG. 7. FIG. 7 is a diagram illustrating an exemplary construction of the wiring board 200.

[0075] Referring to FIG7, the wiring board 200 is, for example, a panel on which a wiring pattern is formed. Specifically, the wiring board 200 includes an insulating substrate 201 having a rectangular shape, a plurality of conductor members 211, a plurality of conductor members 212, a plurality of conductor members 213, a plurality of conductor members 214, a plurality of conductor members 215, a plurality of conductor members 216, conductor members 221 to 223, and conductor members 231 to 236. The insulating substrate 201 is a substrate having insulating properties. The insulating substrate 201 may include a resin (e.g., a thermosetting resin). The insulating substrate 201 corresponds to an example of a "substrate" according to this disclosure.

[0076] Each of the plurality of conductor members 211 is connected to terminal rows T1 or T2 shown in FIG. 6 to electrically connect the individual cells included in the battery stack S1 to each other. Each of the plurality of conductor members 212 is connected to terminal rows T3 or T4 shown in FIG. 6 to electrically connect the individual cells included in the battery stack S2 to each other. Each of the plurality of conductor members 213 is connected to terminal rows T5 or T6 shown in FIG. 6 to electrically connect the individual cells included in the battery stack S3 to each other. Each of the plurality of conductor members 214 is connected to terminal rows T7 or T8 shown in FIG. 6 to electrically connect the individual cells included in the battery stack S4 to each other. Each of the plurality of conductor members 215 is connected to terminal rows T9 or T10 shown in FIG. 6 to electrically connect the individual cells included in the battery stack S5 to each other. Each of the plurality of conductor members 216 is connected to terminal rows T11 or T12 shown in FIG. 6 to electrically connect the individual cells included in the battery stack S6 to each other.

[0077] Conductor component 221 electrically connects battery stacks S1 and S2 to each other. Conductor component 222 electrically connects battery stacks S3 and S4 to each other. Conductor component 223 electrically connects battery stacks S5 and S6 to each other. Conductor components 231, 232, 233, 234, 235 and 236 electrically connect battery stacks S1, S2, S3, S4, S5 and S6 to battery circuit cell 30 respectively (see Figure 3).

[0078] Each of conductor components 211 to 216, 221 to 223, and 231 to 236 is, for example, a plate-like component made of metal. Each of conductor components 221 to 223 may be a U-shaped plate-like component. Each of the conductor components may be a busbar. Each of the conductor components may be made of any material and may have any shape.

[0079] In the example shown in Figure 7, each of conductor members 211 to 216 connects two cells in parallel in the corresponding energy storage pile to obtain a parallel-connected body, and then connects the obtained parallel-connected bodies in series. Each body in the parallel-connected body consists of multiple cells connected in parallel. Conductor member 221 electrically connects the electrode terminal 11 of each of cells 1(1) and 1(2) to the electrode terminal 12 of each of cells 2(1) and 2(2). Conductor member 222 electrically connects the electrode terminal 11 of each of cells 3(1) and 3(2) to the electrode terminal 12 of each of cells 4(1) and 4(2). Conductor member 223 electrically connects the electrode terminal 11 of each of cells 5(1) and 5(2) and the electrode terminal 12 of each of cells 6(1) and 6(2). One end of conductor 231 is connected to the electrode terminal 12 of each of cell 1 (N-1) and cell 1 (N), and the other end of conductor 231 is connected to battery circuit cell 30. One end of conductor 232 is connected to the electrode terminal 11 of each of cell 2 (N-1) and cell 2 (N), and the other end of conductor 232 is connected to battery circuit cell 30. One end of conductor 233 is connected to the electrode terminal 12 of each of cell 3 (N-1) and cell 3 (N), and the other end of conductor 233 is connected to battery circuit cell 30. One end of conductor 234 is connected to the electrode terminal 11 of each of cell 4 (N-1) and cell 4 (N), and the other end of conductor 234 is connected to battery circuit cell 30. One end of conductor 235 is connected to the electrode terminal 12 of each of cell 5 (N-1) and cell 5 (N), and the other end of conductor 235 is connected to battery circuit cell 30. One end of conductor member 236 is connected to the electrode terminal 11 of each of cell 6(N-1) and cell 6(N), and the other end of conductor member 236 is connected to battery circuit cell 30. Furthermore, the battery circuit cell 30 shown in FIG. 3 electrically connects cells 2(N) and 3(N) to each other, and connects cells 4(N) and 5(N) to each other. Therefore, the battery stacks S1 to S6 are electrically connected to each other. In the pattern shown in FIG. 7, multiple parallel-connected components are connected in series.

[0080] The connection method of multiple energy storage cells is not limited to that shown in Figures 6 and 7, and can be changed appropriately. For example, the number of energy storage cells connected in parallel can be three or more, instead of two. All energy storage cells can be connected in series, rather than forming a parallel connection.

[0081] In this embodiment, the wiring pattern of the wiring board 200 is formed by conductor members 211 to 216. Conductor members 211 to 216 are fixed to recesses formed in the surface (+Z side surface) of the insulating substrate 201. A portion of the conductor members 211 to 216 is embedded in the insulating substrate 201. However, forming recesses (height differences) for the conductor members 211 to 216 in the surface of the insulating substrate 201 is not necessary. The conductor members 211 to 216 can be bonded to a flat surface of the insulating substrate 201.

[0082] As shown in Figure 7, a plurality of openings h21 (more specifically, "6 × N" openings h21) are formed in the insulating substrate 201. Each opening h21 is located between the electrode terminals of each battery cell included in the battery stacks S1 to S6, and more specifically below (on the -Z side) the valve 13. Any one of the openings h21 faces the valve 13 of the battery cell 10 in the Z direction. Each opening h21 is, for example, an elongated hole extending through the insulating substrate 201. In the XY plane, the position of each of the plurality of openings h21 coincides with the position of each of the plurality of openings h11 shown in Figure 4. Thus, a through hole h10 (see Figure 8 described below) is formed through the openings h11 and h21, which extends through the lower housing 100 and the insulating substrate 201. The openings h11 and h21 may have the same shape and size in the XY plane.

[0083] N openings h22 arranged in the X direction are formed in each of the following regions: the region between battery stacks S1 and S2 (hereinafter referred to as "Rs1"), the region between battery stacks S2 and S3 (hereinafter referred to as "Rs2"), the region between battery stacks S3 and S4 (hereinafter referred to as "Rs3"), the region between battery stacks S4 and S5 (hereinafter referred to as "Rs4"), and the region between battery stacks S5 and S6 (hereinafter referred to as "Rs5") (see Figure 12 described below). The openings h22 are formed according to the position of the battery cells 10. Each opening h22 is formed between two battery cells 10 adjacent to each other along the Y direction. Each opening h22 is, for example, a circular hole extending through the insulating substrate 201. In the XY plane, the position of each of the plurality of openings h22 coincides with the position of each of the plurality of openings h12 shown in Figure 4. The through-hole h20 (FIG. 3) extending through the lower housing 100 and the wiring board 200 is formed by openings h12 and h22. In this embodiment, openings h12 and h22 have the same shape and size in the XY plane. However, this disclosure is not limited to the above. Openings h12 and h22 may have different shapes and sizes in the XY plane.

[0084] Each of the openings h21 and h22 is formed, for example, by stamping or etching. As will be described in detail below, hydrophobicity is imparted to the insulating substrate 201 by surface treatment, except for the specified portions (see Figure 12). The openings h22 are located in portions that are not hydrophobic. The edge portions of each opening h22 are hydrophilic relative to the other portions.

[0085] Cover members 241 to 246 are disposed on the insulating substrate 201. Therefore, all openings h21 formed in the insulating substrate 201 are covered by cover members 241 to 246. Each of the cover members 241 to 246 includes a base member 202 extending in the X direction and N cover portions 202a arranged in the X direction. The base member 202 may have an adhesive on one surface (adhesive surface). The base member 202 may be, for example, an adhesive tape, such as a polypropylene (PP) tape. The N cover portions 202a are formed on the base member 202. In this embodiment, the cover portions 202a comprise mica. Mica has excellent heat resistance and electrical insulation properties. The N cover portions 202a in each of the cover members 241 to 246 are formed to close the N openings h21 located below a corresponding battery stack in battery stacks S1 to S6. The position of the cover portion 202a is determined according to the position of the opening h21. The size of each cover portion 202a is the same as or larger than the size of each opening h21. For example, N cover portions 202a can be formed on the base member 202 by attaching N mica foils to the adhesive surface of the base member 202. Alternatively, N cover portions 202a can be formed on the base member 202 by forming N through holes in the base member 202 and providing mica foil in each through hole. Cover members 241 to 246 are attached, for example, to the surface (+Z side surface) of the insulating substrate 201, with the adhesive surface of the base member 202 interposed therebetween.

[0086] For example, after the cover members 241 to 246 are attached to the insulating substrate 201, the energy storage piles S1 to S6 shown in FIG. 6 rotate 180° about the X-axis, which is the axis of rotation. 0The battery cells are placed on a wiring board 200, with the surface F10 of each battery cell facing vertically downwards. Then, battery stacks S1 to S6 are connected to the wiring board 200, and the battery stacks S1 to S6 and the wiring board 200 are placed in the lower housing 100. Furthermore, battery circuit cells 30 are connected to the wiring board 200, and a cooling device 20 is placed in the lower housing 100. As a result, the interior of the lower housing 100 has the state shown in FIG. 3. The cooler 22C of the cooling device 20 can be placed in the lower housing 100 together with the battery stacks S1 to S6. Thereafter, the remaining portion of the cooling device 20 can be placed in the lower housing 100, and each of pipes 22A and 22B can be connected to the cooler 22C. The wiring board 200 and each of the battery circuit cells 30 can be fixed to the lower housing 100 with an adhesive (e.g., silicone adhesive).

[0087] The wiring board 200 is electrically connected to the battery circuit cell 30, as shown in the lower part of Figure 3. The battery circuit cell 30 includes a total positive terminal 31, a total negative terminal 32, a J / B 33, a fuse 34, and wires L1 to L4. The total positive terminal 31 is located at the positive end of the entire battery stack S1 to S6 (all battery cells). The total negative terminal 32 is located at the negative end of the entire battery stack S1 to S6 (all battery cells). Wire L1 electrically connects conductor members 232 and 233 to each other. Wire L2 electrically connects conductor members 234 and 235 to each other. Wire L2 is equipped with a fuse 34. Conductor member 236 is connected to the total positive terminal 31. Wire L3 electrically connects the total positive terminal 31 and the J / B 33 to each other. Conductor member 231 is connected to the total negative terminal 32. Wire L4 electrically connects the main negative terminal 32 and J / B 33 to each other. J / B 33 houses various electrical devices. J / B 33 may include at least one of a relay, fuse, resistive element, current sensor, and connector (e.g., a connector to an on-board charger). Battery circuit cell 30 may also include at least one of a battery management system (BMS) and an electronic control unit (ECU). Various sensors (e.g., temperature sensors and voltage sensors) and signal lines that transmit the values ​​detected by the sensors to at least one of the BMS and ECU may be further housed in region R5 of the lower housing 100 (FIG. 4). Voltage sensors may be provided for each parallel-connected unit or for each battery cell. Signal lines may be formed of flexible printed circuit (FPC).

[0088] The electrode terminals of the battery cell 10 and the conductor components of the wiring board 200 can be joined by caulking, thermoforming, or welding (e.g., laser welding). The electrode terminals and conductor components can be fastened to each other. Recesses (counterholes) for accommodating bolt heads and / or washers can be formed in the rear surface (-Z side surface) of the insulating substrate 201.

[0089] Figures 8, 9, 10, and 11 are end views of the energy storage device B taken along lines VIII-VIII, IX-IX, XX, and XI-XI in Figure 3, respectively.

[0090] Referring to Figures 8 through 11, the top cover 110 is, for example, joined to the upper surface (+Z side surface) of each of the side walls W1 through W4 (with adhesive 110b disposed therebetween), and further secured to this upper surface by bolts 110a. For example, the shared panel 120 is joined to the lower surface (-Z side surface) of each of the side walls W1 through W4, with adhesive 120b disposed therebetween. An exhaust path P1 is formed between the bottom wall 101 of the lower housing 100 and the shared panel 120. Each of the side walls W1 through W4 is formed to be hollow. Exhaust paths P2 and P3 are formed within side walls W2 and W3, respectively. Although not shown, exhaust paths are also formed within side wall W4 in a manner equivalent to exhaust path P3 of side wall W3. These exhaust paths communicate with each other. Each of adhesives 110b and 120b can be an adhesive with a thermal conductivity higher than air (e.g., a silicone adhesive).

[0091] As shown in Figure 8, an exhaust port 151a connected to the exhaust valve 151 (Figure 3) is formed in the side wall W2. The exhaust port 151a extends through the side wall W2. Although not shown, an exhaust port connected to the exhaust valve 152 (Figure 3) is also formed in the side wall W2. These exhaust ports communicate with the exhaust path P2.

[0092] As shown in Figures 8 and 11, valve 13 opens when the pressure in the battery cell 10 exceeds a first reference value. Then, due to the pressure and heat of the gas discharged from the inside of the battery cell 10 through valve 13, an orifice facing valve 13 is formed in the cover 202a. The gas discharged from the battery cell 10 flows into exhaust path P1 through this orifice. When the pressure in exhaust path P2 exceeds a second reference value, each of the exhaust valves 151 and 152 shown in Figure 3 opens. The second reference value can be a pressure value lower than the first reference value. Check valves are used, for example, for each of the exhaust valves 151 and 152. When at least one of the exhaust valves 151 and 152 is open, the gas in each exhaust path flows to the opened exhaust valve and is discharged to the outside of the battery storage device B through that exhaust valve. The thickness of the cover 202a provided in the wiring board 200 (Figure 7) is set to allow the orifice to be formed when the valve 13 facing the cover 202a is open (e.g., when valve 13 is open in a fire situation).

[0093] A mica layer 120a (e.g., mica foil) is disposed on the inner (+Z side) surface of the shared panel 120. The mica layer 120a may be provided to overlap all covers 202a in the XY plane. The mica layer 120a may be disposed throughout the entire region R5 shown in FIG. 4. The mica layer 120a protects the shared panel 120 from substances (such as gases, electrolyte solutions, or debris) emitted from the battery cells 10 through the covers 202a.

[0094] As shown in Figure 10, in the lower housing 100, there is a space V1 between the partition wall 103 and the side wall W1. Although not shown, the tube 21A shown in Figure 3 is disposed in space V1. As shown in Figures 8 and 9, in the lower housing 100, there is a space V2 above the battery circuit cell 30. Although not shown, the cooling tube 23 shown in Figure 3 is disposed in space V2. As shown in Figure 11, there is a space V3 between the battery cell 10 located at the -Y side end and the side wall W3 in the lower housing 100. Although not shown, the tube 22A shown in Figure 3 is disposed in space V3. Spaces V1, V2, and V3 are located in regions R1, R2, and R3 in the XY plane, respectively (Figure 4).

[0095] In each energy storage stack, an intermediate member 40 is disposed between two adjacent energy storage cells 10 along the X direction, and a terminal member 40a is disposed on the outer side of the end of the energy storage cell 10 located along the X direction.

[0096] As shown in Figure 8, the intermediate member 40 is located, for example, between monomer 3(N-1) and monomer 3(N). The intermediate member 40 includes a cooler 22C (Figure 3), two insulating pads 41, and two shock-absorbing members 42 (only one is shown). Each of the two insulating pads 41 can be a resin film. In the intermediate member 40 shown in Figure 8, one insulating pad 41 is located between the cooler 22C and monomer 3(N-1), and the other insulating pad 41 is located between the cooler 22C and monomer 3(N). The shock-absorbing members 42 are located at both ends of the intermediate member 40 in the Z direction to suppress the transmission of shock to the cooler 22C. Although Figure 8 only shows the +Z side end of the intermediate member 40, the -Z side end also has the same structure.

[0097] As shown in Figure 8, the terminal member 40a is located, for example, on the outer side (+X side) of the monomer 3(N). The terminal member 40a includes a cooler 22C (Figure 3), an insulating pad 41, an insulating pad 41a, and two shock-absorbing members 42a (only one is shown). The terminal member 40a has essentially the same structure as the intermediate member 40. However, in the terminal member 40a, one of the two insulating pads 41 of the intermediate member 40 is replaced by an insulating pad 41a, which is formed to be thicker than the insulating pad 41. This makes it less likely for shocks to be transmitted from the outside to the energy storage section (energy storage piles S1 to S6). The shock-absorbing members 42a are located at both ends of the terminal member 40a in the Z direction to suppress the transmission of shocks to the cooler 22C. Although only the +Z side end of the terminal member 40a is shown in Figure 8, the -Z side end also has the same structure.

[0098] As shown in Figure 9, the conductor member 232 extends through an opening 104a formed in the partition wall 104. The conductor member 232 extends through the opening 104a and connects to the battery circuit cell 30. Although not shown, the openings through which the conductor members 231, 233, 234, 235 and 236 shown in Figure 3 extend are also formed in the partition wall 104.

[0099] Figure 12 is a diagram illustrating the cross-sectional structure of the wiring board 200. The lower part of Figure 12 shows an end view taken along line XII-XII in the plan view of the wiring board 200 shown in the upper part of Figure 12.

[0100] Referring to Figure 12, the insulating substrate 201 has a surface F1 (vertical upper surface) facing the +Z side and a surface F2 (vertical lower surface) facing the -Z side. The entire surface F2 is formed flat. No conductor members are provided on surface F2. Instead, a plurality of conductor members (including conductor members 211 to 216 and 221 to 223) are formed on surface F1. In addition, a plurality of recesses are formed in surface F1. In surface F1, each recess is formed between adjacent battery packs along the Y direction. Specifically, recesses (i.e., grooves) extending in the X direction are formed in each of Rs1 to Rs5 in Figure 12. An opening h22 is formed in each groove.

[0101] The recess in Rs1 has an inclined surface that slopes downward from terminal row T2 toward opening h22 and an inclined surface that slopes downward from terminal row T3 toward opening h22. The recess in Rs2 has an inclined surface that slopes downward from terminal row T4 toward opening h22 and an inclined surface that slopes downward from terminal row T5 toward opening h22. The recess in Rs3 has an inclined surface that slopes downward from terminal row T6 toward opening h22 and an inclined surface that slopes downward from terminal row T7 toward opening h22. The recess in Rs4 has an inclined surface that slopes downward from terminal row T8 toward opening h22 and an inclined surface that slopes downward from terminal row T9 toward opening h22. The recess in Rs5 has an inclined surface that slopes downward from terminal row T10 toward opening h22 and an inclined surface that slopes downward from terminal row T11 toward opening h22. By forming such inclined surfaces, water on surface F1 is guided to opening h22 by gravity and may fall into exhaust path P1 (Figures 8 to 11) through opening h22.

[0102] The insulating substrate 201 has a hydrophilic portion 201a (first portion) located at the edge of each of the plurality of openings h22 and a hydrophobic portion (second portion) with a higher degree of hydrophobicity than the hydrophilic portion 201a. In this embodiment, the portion of the insulating substrate 201 other than the hydrophilic portion 201a is the hydrophobic portion. The degree of hydrophobicity can be represented by, for example, the contact angle. As the contact angle increases, the degree of hydrophobicity increases. The hydrophilic portion 201a and the hydrophobic portion of the insulating substrate 201 can be formed by selectively applying a waterproofing treatment to the portions corresponding to the hydrophobic portions (other than the edge portions of the openings h22). The waterproofing treatment can be a silicone or fluorine treatment of the coating surface F1 of the insulating substrate 201. By providing the hydrophilic portion 201a at the edge of the opening h22, water on the surface F1 is guided to the edge of the opening h22 and may fall into the venting path P1 (Figures 8 to 11) through the opening h22.

[0103] Figure 13 is an end view of the energy storage device B taken along line XIII-XIII in Figure 3.

[0104] Referring to Figures 13 and 3 to 12, the energy storage device B includes two energy storage cells 10 (e.g., cell 1 (6) and cell 2 (6)) adjacent to each other in the Y direction, and a wiring board 200. The wiring board 200 has an insulating substrate 201 and conductor members 211 (first conductor member) and 212 (second conductor member) disposed on the surface F1 of the insulating substrate 201. Cell 1 (6) has an electrode terminal 11 (first electrode terminal) connected to the conductor member 211 and an explosion-proof valve (valve 13 shown in Figure 5) on the surface F10 (vertical lower surface). Cell 2 (6) has an electrode terminal 12 (second electrode terminal) connected to the conductor member 212 and an explosion-proof valve (valve 13 shown in Figure 5) on the surface F10 (vertical lower surface). In the insulating substrate 201, a recess R10 and an opening h22 are disposed between the electrode terminal 11 of cell 1 (6) and the electrode terminal 12 of cell 2 (6). Specifically, a recess R10 is formed between electrode terminal 11 of monomer 1 (6) and electrode terminal 12 of monomer 2 (6). An opening h22 is formed in the recess R10. The opening h22 may be located in the middle between electrode terminal 11 of monomer 1 (6) and electrode terminal 12 of monomer 2 (6). The opening h12 is formed in the bottom wall 101 of the lower housing 100 (see FIG4). The opening h12 is located below the opening h22 (on the -Z side). The opening h22 communicates with the exhaust path P1 through the opening h12. The openings h12 and h22 are continuous in the Z direction to form a through hole h20.

[0105] The insulating substrate 201 has a first inclined portion F11 that slopes downward from the electrode terminal 11 of monomer 1 (6) toward the opening h22 and a second inclined portion F12 that slopes downward from the electrode terminal 12 of monomer 2 (6) toward the opening h22. The insulating substrate 201 is located on the vertically lower side (-Z side) of the surface F10 (including valve 13) of each of monomers 1 (6) and 2 (6). The exhaust path P1 is located on the vertically lower side (-Z side) of the insulating substrate 201.

[0106] Even when water is generated in at least one of the adjacent cells 1 (6) and 2 (6) (e.g., water droplets W shown in FIG. 13), the water falls into the exhaust path P1 through the through-hole h20. Therefore, even when water is generated in one of the adjacent cells 1 (6) and 2 (6), the diffusion of water to the other cell is suppressed. In addition, the gas discharged from each of cells 1 (6) and 2 (6) flows through the exhaust path P1 (see FIG. 8). Therefore, the water in the exhaust path P1 is discharged to the outside along with the gas through the exhaust valves 151 and 152.

[0107] In the following text, a pair of adjacent storage cells 10 (first storage cell and second storage cell) in the Y direction will be referred to as a "Y cell pair". In this embodiment, as shown in FIG3, the energy storage device B has "5×N" Y cell pairs. In each of the energy storage stacks S2 to S5, one storage cell 10 constitutes two Y cell pairs. For example, cell 2 (1) together with cell 1 (1) constitutes a Y cell pair, and also together with cell 3 (1) constitutes a Y cell pair. Among the "5×N" Y cell pairs, the Y cell pairs other than the three Y cell pairs connected by conductor members 221, 222 and 223 have the structure shown in FIG13.

[0108] The shape of the recess located between two adjacent battery cells 10 in the substrate is not limited to the shape shown in FIG. 13 and can be appropriately changed. FIG. 14 is a diagram showing a modified example of the recess R10 shown in FIG. 13. The insulating substrate 201A shown in FIG. 14 has a recess R10A instead of the recess R10 with inclined sidewalls (FIG. 13). The recess R10A has a bottom surface and sidewalls forming right angles with the bottom surface. The recess R10A is located between the electrode terminals of the Y-cell pair, for example, between electrode terminal 11 of cell 1 (6) and electrode terminal 12 of cell 2 (6). The recess R10 or R10A can be formed from one end to the other in the X direction of the insulating substrate 201. However, the present disclosure is not limited to the above. The sidewalls of the recess can be formed (e.g., on the four sides) around one or more openings h22.

[0109] Forming a recess between two adjacent battery cells 10 in the substrate is not necessary. Figure 15 is a diagram showing an example where there is no recess between two adjacent battery cells 10 in the substrate. The front and rear surfaces (surfaces F1 and F2) of the insulating substrate 201B shown in Figure 15 are formed as flat surfaces. An opening h22 extending through the insulating substrate 201B between the electrode terminals of the Y cell pair, together with an opening h12 located below the opening h22 and extending through the bottom wall 101 of the lower housing 100, forms a through hole h20.

[0110] Multiple through-holes can be formed between two adjacent battery cells 10 in the substrate. Figure 16 is a diagram showing an example of multiple through-holes formed between two adjacent battery cells 10 in the substrate. Five openings h22 are formed in a recess R10 of the insulating substrate 201C shown in Figure 16. The recess R10 is located between the electrode terminals of the Y-cell pair. Each of the five openings h22 in the recess R10, together with an opening h12 located below the opening h22 and extending through the bottom wall 101 of the lower housing 100, forms a through-hole h20. The battery storage device shown in Figure 16 has five through-holes h20 communicating with the exhaust path P1. A hydrophilic portion 201a is provided at the edge portion of each of the five openings h22. The number of openings h22 located between the electrode terminals of the Y-cell pair can be appropriately varied and can be equal to or greater than two and equal to or less than four, or equal to or greater than six.

[0111] In the above embodiments, openings h22 are formed in all Y-cell pairs (see Figures 7 and 12). This results in greater freedom in designing wiring patterns on the insulating substrate 201. However, this disclosure is not limited to the above. Openings h22 may be formed only in specified Y-cell pairs. For example, openings h22 may not be formed below each conductor member 221, 222, and 223.

[0112] Figure 17 is a diagram showing a first modified example of an opening located between two adjacent battery cells 10 in a substrate. In the insulating substrate 201D shown in Figure 17, each of the plurality of openings h22A is formed to extend over a plurality of Y-cell pairs. The opening h22A is longer in the X direction than the opening h22 shown in Figure 7. The opening h22A is slit-shaped and has a size in the X direction corresponding to three battery cells 10. The size of the opening in the X direction in the substrate can be suitably changed and can be a size corresponding to two battery cells 10, or it can be a size corresponding to four or more battery cells 10.

[0113] Figure 18 is a diagram showing a second variation of an opening located between two adjacent battery cells 10 in a substrate. In the insulating substrate 201E shown in Figure 18, each of the plurality of openings h22B is formed to extend over the entire battery stack. The opening h22B has a dimension extending from one end of the battery stack to the other in the X direction. An opening h22B formed to extend in the X direction is disposed between adjacent battery cells.

[0114] Coolers can be provided on the substrate. Figure 19 is a diagram showing an example of a substrate including coolers. One or more coolers 50 are disposed on surface F2 (vertical lower surface) of the insulating substrate 201F shown in Figure 19. Coolers 50 can be provided for each battery pack. For example, the insulating substrate 201F includes six coolers 50 (only two are shown), each cooler being formed to be elongated in the X direction. The coolers 50 are fixed to recesses formed in surface F2 of the insulating substrate 201F. The coolers 50 are partially embedded in the insulating substrate 201F. A portion of the cooler 50 is located near the through-hole h20. The coolers 50 cool the gas around and exiting from valve 13 in the Y-cell pair (e.g., gas in exhaust path P1).

[0115] A water-absorbing member may be disposed between an opening h22 formed in the insulating substrate 201 and an exhaust path P1 located below the opening h22. Figure 20 is a diagram showing an example of a substrate including a water-absorbing member. In the example shown in Figure 20, a planar water-absorbing member 60 is disposed on the outer surface (-Z side surface) of the bottom wall 101 of the lower housing 100. The water-absorbing member 60 is located below the through-hole h20 to close the through-hole h20. The water-absorbing member 60 has water-absorbing properties and absorbs water falling from the surface F1 of the insulating substrate 201 into the through-hole h20. The water absorbed by the water-absorbing member 60 is evaporated by wind and / or heat received from the fluid flowing through the exhaust path P1. When the amount of water falling onto the water-absorbing member 60 exceeds a predetermined amount of water retained by the water-absorbing member 60, the water not absorbed by the water-absorbing member 60 falls into the exhaust path P1. By providing the water-absorbing member 60, the amount of water falling into the exhaust path P1 can be reduced. The water-absorbing member 60 may include fibers (e.g., polyester fibers) that absorb water by capillary action. The absorbent component 60 may include a fabric that has undergone absorbent and rapid drying treatment.

[0116] As an alternative to or supplement to the through-hole h20, a protrusion can be provided on the substrate.

[0117] Figure 21 is a diagram illustrating a first example in which a protrusion is provided between two adjacent battery cells 10 in the substrate. The aforementioned through-hole h20 is not formed in the insulating substrate 201G and bottom wall 101A shown in Figure 21. The protrusion M1 is fixed to the surface F1 of the insulating substrate 201G. The protrusion M1 can be soldered or bonded to the insulating substrate 201G, or it can be fastened to the insulating substrate 201G. Alternatively, the protrusion M1 can be integrally formed with the insulating substrate 201G. The protrusion M1 is located between the electrode terminals of the Y-cell pair. The surface of the protrusion M1 can be waterproofed. The protrusion M1 is higher in height than the surface F10 of each of the cells 1 (6) and 2 (6) constituting the Y-cell pair. The top of the protrusion M1 is located on the +Z side of the surface F10 of cells 1 (6) and 2 (6). Because of the protrusion M1 between the electrode terminals of adjacent cells 1 (6) and 2 (6) (which are adjacent to each other), water diffusion to the other cell is suppressed even when water is generated in one of these cells. This makes it less likely to cause a short circuit between the electrode terminals of adjacent cells.

[0118] In the example shown in Figure 21, a protrusion M1 is disposed between the electrode terminals of the Y-cell pair. However, the number of protrusions disposed between the electrode terminals of the Y-cell pair can be appropriately varied, and can be equal to or greater than two and equal to or less than five, or equal to or greater than six.

[0119] Figure 22 is a diagram illustrating a second example in which a protrusion is provided between two adjacent battery cells 10 in the substrate. In the example shown in Figure 22, protrusions M21 and M22 are fixed to the surface F1 of the insulating substrate 201B shown in Figure 15. Additionally, a through-hole h20 is provided in the Y direction between protrusions M21 and M22. These protrusions M21, M22, and through-hole h20 suppress short circuits between the electrode terminals of adjacent cells 1 (6) and 2 (6). Each of the protrusions M21 and M22 and the insulating substrate 201B can be formed and joined individually, or can be integrally formed seamlessly.

[0120] In the above embodiment, the openings through which conductor members 231 to 236 extend are formed in the partition wall 104 (see FIG. 9). However, this disclosure is not limited to the above. The partition wall 104 can be separated. FIG. 23 is a diagram showing a modified example of the partition wall. The partition wall 104A shown in FIG. 23 is composed of multiple partitions. No partitions are provided in the portions corresponding to conductor members 231 to 236. Conductor members 231 to 236 can span the space between partitions arranged in the Y direction in the X direction. Alternatively, wires (e.g., cables) connected to the wiring board 200 can extend above the partition wall 104 shown in FIG. 3 and connect to the battery circuit cell 30. A device for cooling the battery circuit cell 30, including a cooler (including a cooling pipe 23), can be provided below the battery circuit cell 30. It is not necessary to provide cell coolers (e.g., cooler 22C) for cooling the battery cells between adjacent cells. Cell coolers can be provided above the battery cells. Cell coolers can be provided to cover the upper surfaces of all battery cells. The partition walls 103 and 104 shown in Figure 3 are not essential. At least one of partition walls 103 and 104 can be omitted. At least one of exhaust valves 151 and 152 can be omitted. Gas flowing through each exhaust path can be discharged to the outside of the energy storage device B through an exhaust port (e.g., exhaust port 151a). The discharged gas can be guided to a designated location by a pipe disposed outside the housing of the energy storage device B.

[0121] The various features associated with the above-described energy storage device (features described in the embodiments and variations) can be applied in any combination.

[0122] There are no particular restrictions on the intended use of energy storage devices. Energy storage devices can be used in vehicles other than automobiles (electric motorcycles, electric wheelchairs, railway vehicles, ships, airplanes, electric vertical takeoff and landing aircraft (eVTOL), amphibious aircraft, etc.), mobile machines (agricultural machines, construction machines, etc.), unmanned mobile bodies (automated guided vehicles (AGVs), mobile robots, drones, robotic cleaners, space probes, etc.), wearable robots, stationary robots (e.g., industrial robots), or buildings (houses, factories, etc.).

[0123] Although embodiments of this disclosure have been described, it should be understood that the embodiments disclosed herein are illustrative in every respect and not restrictive. The scope of this disclosure is defined by the terminology of the claims and is intended to include any variations within the scope and meaning equivalent to the terminology of the claims.

Claims

1. An energy storage device, comprising: First battery cell; Second battery cell; The wiring board includes a substrate and a plurality of conductor members disposed on a vertical upper surface of the substrate. The plurality of conductor members include a first conductor member and a second conductor member. The first battery cell includes a first electrode terminal connected to the first conductor member on its vertical lower surface. The second battery cell includes a second electrode terminal connected to the second conductor member on its vertical lower surface. At least one of a protrusion, a recess, and a through hole is disposed in a portion of the substrate between the first electrode terminal and the second electrode terminal.

2. The energy storage device according to claim 1, wherein one or more through holes are formed in the portion of the substrate between the first electrode terminal and the second electrode terminal.

3. The energy storage device according to claim 2, wherein the substrate comprises: One or more first portions located at the edge portion of the one or more through holes; And a second part with a higher degree of hydrophobicity than the first part.

4. The energy storage device according to claim 2, wherein the substrate comprises: A first inclined portion that slopes downward from the first electrode terminal toward the one or more through holes; And a second inclined portion that slopes downward from the second electrode terminal toward the one or more through holes.

5. The energy storage device according to claim 2, wherein a recess is formed in the portion of the substrate between the first electrode terminal and the second electrode terminal, and the one or more through holes are formed in the recess.

6. The energy storage device according to any one of claims 2 to 5, wherein the energy storage device includes an exhaust path through which gas discharged from each of the first and second energy storage cells flows, and the one or more through holes are in communication with the exhaust path.

7. The energy storage device according to claim 6, wherein the water-absorbing component is disposed between the one or more through holes and the exhaust path.

8. The energy storage device according to claim 6, wherein each of the first energy storage cell and the second energy storage cell further includes an explosion-proof valve on its vertical lower surface, the substrate is located on the vertical lower side of the explosion-proof valve of each of the first energy storage cell and the second energy storage cell, the exhaust path is located on the vertical lower side of the substrate, and the cooler is disposed on the vertical lower surface of the substrate.

9. The energy storage device according to claim 1, wherein one or more protrusions are formed in the portion of the substrate between the first electrode terminal and the second electrode terminal.

Images