Energy storage device

Abstract

To provide an energy storage device that prevents short circuits between the electrode terminals of adjacent energy storage cells. [Solution] The energy storage device B comprises a first energy storage cell (cell 1(6)), a second energy storage cell (cell 2(6)), and a wiring board. The wiring board has a substrate (insulating substrate 201) and a plurality of conductor members provided on the vertically upper surface F1 of the substrate. The plurality of conductor members include a first conductor member (conductor member 211) and a second conductor member (conductor member 212). The first energy storage cell has a first electrode terminal (electrode terminal 11) connected to the first conductor member on the vertically lower surface F10. The second energy storage cell has a second electrode terminal (electrode terminal 12) connected to the second conductor member on the vertically lower surface F10. At least one of a convex portion, a concave portion, and a through hole is provided between the first electrode terminal and the second electrode terminal of the substrate.

Description

Technical Field

[0001] The present disclosure relates to a power storage device including a plurality of power storage cells.

Background Art

[0002] Chinese Patent Application Publication No. 116686151 (Patent Document 1) discloses a power storage device including a plurality of power storage cells fixed in a case (accommodation cavity). The electrode terminals of each power storage cell are provided facing the bottom wall of the case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power storage device described in the above Patent Document 1, water generated in the case due to condensation or the like may short-circuit the electrode terminals of adjacent power storage cells.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power storage device in which the electrode terminals of adjacent power storage cells are less likely to short-circuit.

Means for Solving the Problems

[0006] According to the present disclosure, the following power storage device is provided.

[0007] (Article 1) The energy storage device comprises a first energy storage cell, a second energy storage cell, and a wiring board. The wiring board has a substrate and a plurality of conductor members provided on the vertically upper surface of the substrate. The plurality of conductor members include a first conductor member and a second conductor member. The first energy storage cell has a first electrode terminal connected to the first conductor member on its vertically lower surface. The second energy storage cell has a second electrode terminal connected to the second conductor member on its vertically lower surface. At least one of a protrusion, a recess, and a through hole is provided between the first electrode terminal and the second electrode terminal of the substrate.

[0008] With the above configuration, even if water is generated in one of the adjacent energy storage cells (the first and second energy storage cells), the spread of water to the other energy storage cell is suppressed. As a result, the electrode terminals of adjacent energy storage cells are less likely to short-circuit.

[0009] (Article 2) In the energy storage device described in Article 1, one or more through holes are formed in the substrate between the first electrode terminal and the second electrode terminal.

[0010] The presence of one or more through-holes between the electrodes of adjacent energy storage cells makes it less likely for short circuits to occur at the electrode terminals due to water.

[0011] (3) In the energy storage device described in paragraph 1 or 2, the substrate has one or more first parts located at the edges of one or more through holes, and a second part having a higher degree of hydrophobicity than the first parts.

[0012] The first portion is located at the edge of the through-hole, which makes it easier for water between the electrodes to be guided into the through-hole.

[0013] (Article 4) In the energy storage device described in Article 2 or Article 3, the substrate has a first inclined portion that slopes downward from the first electrode terminal toward one or more through holes, and a second inclined portion that slopes downward from the second electrode terminal toward one or more through holes.

[0014] The first and second inclined sections described above facilitate the flow of water between the electrodes into the through-holes.

[0015] (Article 5) The energy storage device described in any one of Articles 2 to 4 has a recess formed between the first electrode terminal and the second electrode terminal of the substrate, and one or more through holes are formed in the recess.

[0016] According to the above configuration, the presence of recesses and through holes between the electrodes of adjacent energy storage cells makes it less likely for short circuits to occur at the electrode terminals due to water.

[0017] (Item 6) In the energy storage device described in any one of items 2 to 5, the energy storage device has an exhaust passage through which gas discharged from each of the first and second energy storage cells flows. One or more through holes communicate with the exhaust passage.

[0018] With the above configuration, water that falls into the through-hole is more easily discharged along with the exhaust.

[0019] (Clause 7) In the energy storage device described in paragraph 6, a water-absorbing material is provided between one or more through holes and the exhaust passage.

[0020] The above-mentioned absorbent material can reduce the amount of water (liquid) that falls into the exhaust passage.

[0021] (Section 8) In the energy storage device described in Section 6 or 7, each of the first and second energy storage cells is further provided with an explosion-proof valve on its vertically lower surface. The substrate is located vertically below the explosion-proof valves of each of the first and second energy storage cells. The exhaust passage is located vertically below the substrate. A cooler is provided on the vertically lower surface of the substrate.

[0022] The above-mentioned cooler makes it easier to cool the area around the explosion-proof valve and the gas discharged from the explosion-proof valve.

[0023] (Clause 9) In the energy storage device described in any one of paragraphs 1 to 8, one or more protrusions are formed on the substrate between the first electrode terminal and the second electrode terminal.

[0024] The presence of the convex portion between the electrodes of adjacent power storage cells makes it difficult for a short circuit of the electrode terminals to occur due to water. The convex portion may be applied together with a concave portion and / or a through hole.

[0025] As another form, a vehicle including the power storage device according to any one of claims 1 to 9 may be provided.

Advantages of the Invention

[0026] According to the present disclosure, it is possible to provide a power storage device in which short circuits between electrode terminals of adjacent power storage cells are less likely to occur.

Brief Description of the Drawings

[0027] [Figure 1] It is a figure which shows the vehicle provided with the power storage device which concerns on embodiment of this indication. [Figure 2] It is a figure which shows schematic structure of the power storage device which concerns on embodiment of this indication. [Figure 3] It is the figure which looked at the inside of the lower case of the power storage device which concerns on this embodiment from the top. [Figure 4] It is a figure which shows the lower case of the empty state of the power storage device which concerns on this embodiment. [Figure 5] It is a figure which shows an example of the structure of the power storage cell which concerns on this embodiment. [Figure 6] It is the figure which looked at each power storage cell in the lower case shown in FIG. 3 from the bottom. [Figure 7] It is a figure which shows an example of the structure of the wiring board in the lower case shown in FIG. 3. [Figure 8] It is an end view of the power storage device taken along line VIII-VIII in FIG. 3. [Figure 9] It is an end view of the power storage device taken along line IX-IX in FIG. 3. [Figure 10] It is an end view of the power storage device taken along line X-X in FIG. 3. [Figure 11] It is an end view of the power storage device taken along line XI-XI in FIG. 3. [Figure 12] It is a figure for demonstrating the cross-sectional structure of the wiring board shown in FIG. 7. [Figure 13] Figure 3 is an end view of the energy storage device on line XIII-XIII. [Figure 14] This figure shows a modified example of the recess shown in Figure 13. [Figure 15] This figure shows an example where the recess shown in Figure 13 is not formed. [Figure 16] Figure 13 shows an example in which multiple through holes are formed. [Figure 17] This figure shows a first modified example of the opening in the substrate shown in Figure 13. [Figure 18] This figure shows a second modified example of the opening in the substrate shown in Figure 13. [Figure 19] This figure shows an example where a cooler is provided on the substrate shown in Figure 13. [Figure 20] This figure shows an example where a water-absorbing material is provided on the substrate shown in Figure 13. [Figure 21] This figure shows a first example in which the through-hole shown in Figure 13 is changed to a protrusion. [Figure 22] This figure shows a second example in which the through-hole shown in Figure 13 is changed to a protrusion. [Figure 23] This figure shows a modified example of the partition wall shown in Figure 4. [Modes for carrying out the invention]

[0028] Embodiments of this disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated. In the drawings used below, the X-axis, Y-axis, and Z-axis refer to three mutually orthogonal axes. Hereafter, the direction indicated by the arrows on the X-axis, Y-axis, and Z-axis will be indicated by a "+" sign, and the opposite direction will be indicated by a "-" sign.

[0029] Figure 1 shows a vehicle equipped with the energy storage device according to this embodiment. In Figure 1, the -X side corresponds to the front of vehicle 1, and the +X side corresponds to the rear of vehicle 1. The -Z side corresponds to the downward (downward in the vertical direction), and the +Z side corresponds to the upward (upward in the vertical direction).

[0030] Referring to Figure 1, Vehicle 1 is equipped with a power storage device B. Power storage device B may function as a power storage device for driving, commonly referred to as a "battery pack". Vehicle 1 is configured to be able to run using the power output from power storage device B. Vehicle 1 may be equipped with a motor that rotates the drive wheels of Vehicle 1 using the power supplied from power storage device B. Vehicle 1 is, for example, an electric vehicle (BEV) without an internal combustion engine. However, it is not limited to this, and Vehicle 1 may be an HEV (hybrid electric vehicle) or PHEV (plug-in hybrid electric vehicle) equipped with an internal combustion engine, or another electric vehicle (xEV).

[0031] The energy storage device B is installed, for example, under the floor of vehicle 1. The energy storage device B may also be connected to the body of vehicle 1. The energy storage device B has brackets 111, 112 at the -X end and brackets 121, 122 at the +X end (see Figure 3, described later). Although not shown in Figure 1, the energy storage device B also has brackets at both ends in the Y direction (for example, brackets 131, 132 shown in Figure 3, described later). The energy storage device B is connected to the body of vehicle 1 (for example, the floor panel) by fastening these brackets to, for example, the floor member of vehicle 1. At least a part of the housing of the energy storage device B may function as a frame member of vehicle 1. However, the configuration is not limited to the above, and the energy storage device B may also be installed on the floor of vehicle 1.

[0032] Figure 2 shows a schematic configuration of the energy storage device B. Referring to Figure 2, the energy storage device B includes a lower case 100 (first housing member), an upper cover 110 (second housing member), and a shear panel 120 (third housing member), which function as the housing of the energy storage device B. The lower case 100 opens upward (towards the +Z side) and houses multiple energy storage cells and various components related to these energy storage cells. As will be described in detail later, the lower case 100 houses energy storage cells, a cooler, and a junction box (hereinafter referred to as "J / B") (see Figure 3). The upper cover 110 and the shear panel 120 are fixed to the lower case 100. The upper cover 110 is positioned above the lower case 100 and functions as a lid for the lower case 100. The shear panel 120 is positioned below the lower case 100 (towards the -Z side) and suppresses impacts to the lower case 100 due to road surface interference. Furthermore, an exhaust passage is formed between the lower case 100 and the share panel 120. The upper cover 110 and the share panel 120 correspond to the +Z side and -Z side ends of the energy storage device B, respectively. The housing of the energy storage device B basically seals the space inside the housing (internal space). However, when a valve provided in the housing is opened, the internal space communicates with the external space through that valve.

[0033] Figure 3 is a view of the inside of the lower case 100 from the +Z side with the upper cover 110 removed. Referring to Figure 3, the lower case 100 houses the energy storage stacks S1 to S6, the cooling device 20, the battery circuit unit 30, and the wiring board 200. Each of the energy storage stacks S1 to S6 includes a plurality of energy storage cells 10 arranged in the X direction. Details of the configuration of each energy storage cell will be described later. The wiring board 200 has wiring patterns for the energy storage stacks S1 to S6. The wiring board 200 may also function as a terminal block. The cooling device 20 includes ports 20A, 20B, pipes 21A, 21B extending in the Y direction, pipes 22A, 22B extending in the X direction, a plurality of coolers 22C extending in the Y direction, and cooling pipes 23. These are connected in the following order from the upstream side: port 20A, pipe 21A, pipe 22A, cooling pipe 23, pipe 22B, pipe 21B, and port 20B. Pipes 22A and 22B are connected via multiple coolers 22C (cooling plates) arranged in the X direction. Coolers 22C are placed between adjacent energy cells in the energy storage stacks S1 to S6. These adjacent energy cells are cooled by a refrigerant flowing through a channel formed inside the cooler 22C. Cooler 22C has channels communicating with pipes 22A and 22B, respectively. Cooling pipe 23 is configured to cool the battery circuit unit 30. The battery circuit unit 30 may be a single unit or may include multiple units.

[0034] Figure 4 shows the lower case 100 in an empty state (nothing is stored inside).

[0035] Referring to Figure 4, the lower case 100 has a bottom wall 101 (bottom) and a peripheral wall 102 (periphery). 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, +X side, -Y side, and +Y side ends of the lower case 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, with side wall W22 being the furthest to the +X side. Brackets 121 and 122 (Figure 1) are provided on side walls W21 and W23, respectively. Exhaust valves 151 and 152 are provided on side wall W22. Side wall W22 is connected to side walls W3 and W4 via side walls W21 and W23, respectively. Furthermore, the opposite ends (-X side) of side walls W3 and W4 are connected to each other via side wall W1, which extends in the Y direction. Brackets 131 and 132 are provided on side walls W3 and W4, respectively. Brackets 111 and 112 (Figure 1) are provided on side wall W1. Each of side walls W1 to W4 rises from the periphery of the bottom wall 101 toward the +Z side. The internal space of the lower case 100 is surrounded by side walls W1 to W4.

[0036] The bottom wall 101 is provided with partition walls 103 and 104 extending in the Y direction. Each of the partition walls 103 and 104 may be fastened to the bottom wall 101. Partition wall 104 is located on the +X side of partition wall 103. Each of the partition walls 103 and 104 stands upright on the +Z side from the bottom wall 101. Region R5 is a rectangular area located in the center of the lower case 100 and is partitioned by partition walls 103 and 104. Region R5 is the area where the wiring board 200 and the energy storage stacks S1 to S6 (Figure 3) are arranged. Region R5 is located between partition walls 103 and 104 (inside partition wall 103 and inside partition wall 104). Partition walls 103 and 104 may apply restraining force to the energy storage stacks S1 to S6 from both sides in the X direction. Each of the partition walls 103 and 104 may be a cross frame.

[0037] In region R5, openings h11 are formed at the positions where each energy storage cell is located. Each of the multiple openings h11 is positioned in the Z direction to face the valve 13 of the energy storage cell 10 (see Figure 5), which will be described later. When multiple openings h11 are aligned in the X direction, a row of openings h11 (hereinafter referred to as the "first opening row") is formed. Six first opening rows are formed in the bottom wall 101. In addition, openings h12 are formed between two adjacent openings h11 in the Y direction. When multiple openings h12 are aligned in the X direction, a row of openings h12 (hereinafter referred to as the "second opening row") is formed. Five second opening rows are formed in the bottom wall 101. Openings h11 are, for example, elongated holes penetrating the bottom wall 101. Openings h12 are, for example, round holes penetrating the bottom wall 101. However, the shapes of openings h11 and h12 can be changed as appropriate. Each of the openings h11 and h12 is formed, for example, by punching.

[0038] Regions R3 and R4 are provided on the -Y and +Y sides of region R5, respectively. Region R1 is provided on the outside of partition wall 103 (-X side). Region R2 is provided on the outside of partition wall 104 (+X side). Region R2 is the region where the battery circuit unit 30 (Figure 3) is located. Region R2 is located at the +X end of the lower case 100 and is partitioned by partition wall 104 and side wall W2.

[0039] In this embodiment, the bottom wall 101, the peripheral wall 102, and the partition walls 103 and 104 are each made of metal. However, these materials can be changed as appropriate. The bottom wall 101, the peripheral wall 102, and the partition walls 103 and 104 may be made of the same material or of different materials. The bottom wall 101, the peripheral wall 102, and the partition walls 103 and 104 may be made separately and joined together, or they may be made seamlessly and integrally.

[0040] Referring to Figures 3 and 4, ports 20A and 20B are located on the side wall W1. Ports 20A and 20B are located approximately in the center of the side wall W1 in the Y direction. Port 20B is located on the +Y side of port 20A. Piping 21A and 21B are located in region R1. Piping 22A and 22B are located in regions R3 and R4, respectively. Each of the pipes 21A, 21B, 22A, and 22B is positioned to cool the periphery (regions R1, R3, and R4) of the energy storage device B. Cooling piping 23 is located in region R2. Multiple coolers 22C are located in region R5.

[0041] The refrigerant supplied from port 20A to pipe 21A flows through pipe 21A towards the -Y side. The refrigerant flowing from pipe 21A into pipe 22A flows through pipe 22A towards cooling pipe 23 towards the +X side, while also flowing into the respective flow paths of the multiple coolers 22C. The refrigerant flowing from pipe 22A into cooler 22C flows towards pipe 22B towards the +Y side, cooling the energy storage stacks S1 to S6. The refrigerant flowing from pipe 22A into cooling pipe 23 flows towards pipe 22B towards the +Y side, cooling the battery circuit unit 30. The refrigerant flowing from cooler 22C or cooling pipe 23 into pipe 22B flows through pipe 22B towards pipe 21B towards the -X side. After that, the refrigerant flows through pipe 21B towards the -Y side and flows out from port 20B.

[0042] As described above, the cooling device 20 is configured to cool the energy storage device B when it is in a high-temperature state. However, when the temperature of the energy storage device B is low due to the influence of weather or location (e.g., a cold region), the refrigerant may raise the temperature of the energy storage device B. The refrigerant may be circulated by a pump (not shown) connected to ports 20A and 20B. The vehicle 1 (Figure 1) may be equipped with a device (heat exchanger, chiller, heater, etc.) to regulate the temperature of the refrigerant. The refrigerant may be either a liquid (e.g., water, oil, or antifreeze) or a gas (e.g., carbon dioxide).

[0043] In this embodiment, the wiring board 200 is placed on the +Z side of the bottom wall 101, and the energy storage stacks S1 to S6 are further placed on the +Z side of the wiring board 200.

[0044] Figure 5 shows an example of the configuration of a storage cell constituting each of the energy storage stacks S1 to S6. Referring to Figure 5, the storage cell 10 comprises a case 10a and an electrode body 10b housed in the case 10a. The case 10a is a rectangular case in the shape of a rectangular parallelepiped. The electrode body 10b may include one or more windings (for example, two windings). The windings have a structure in which, for example, a positive electrode sheet and a negative electrode sheet are wound with a separator in between. Each of the positive electrode sheet and the negative electrode sheet includes an electrode foil and an active material layer. The storage cell 10 is a secondary battery such as a lithium-ion battery, nickel-metal hydride battery, or sodium-ion battery. In this embodiment, a liquid-type lithium-ion battery is used as the storage cell 10. The case 10a houses the electrolyte together with the electrode body 10b. The electrolyte includes, for example, an organic solvent and a lithium salt. Examples of lithium-ion batteries include LFP batteries that use lithium iron phosphate as the positive electrode active material, or ternary batteries that use NMC (nickel-manganese-cobalt) as the positive electrode active material. The type of secondary battery is not limited to those mentioned above; for example, all-solid-state secondary batteries may also be used. Instead of wound materials, laminates (for example, laminates in which a positive electrode sheet and a negative electrode sheet are laminated with a separator in between) may be used.

[0045] Electrode terminals 11 and 12 and a valve 13 are provided on surface F10 of case 10a. Surface F10 corresponds to one end face in the height direction of the energy storage cell 10. Valve 13 functions as an explosion-proof valve. Case 10a is basically maintained in a sealed state. However, if the pressure inside case 10a exceeds a first reference value, valve 13 opens to reduce the pressure inside case 10a. Also, electrode terminals 11 and 12 are electrically connected to the positive electrode sheet and negative electrode sheet of electrode body 10b, respectively, and function as positive and negative electrode terminals. The peripheral parts of case 10a around electrode terminals 11 and 12 (for example, the parts shown by dashed lines in Figure 5) may be made of insulating material, and the other parts may be made of metal. However, the material of case 10a is arbitrary and not limited to this.

[0046] In this embodiment, each of the energy storage stacks S1 to S6 shown in Figure 3 is composed of multiple energy storage cells 10 arranged in the X direction. Each energy storage cell included in energy storage stacks S1 to S6 has the same configuration (see Figure 5). By forming the energy storage stacks S1 to S6 using common energy storage cells 10, the manufacturing of the energy storage device B becomes easier and manufacturing costs can be reduced. However, this is not limited to this, and each energy storage stack may include multiple types of energy storage cells. Also, the number of energy storage stacks can be changed as appropriate. The number of energy storage stacks may be one or more.

[0047] Figure 6 shows the energy storage stacks S1 to S6 arranged inside the lower case 100, viewed from the -Z side. Referring to Figure 6, each of the energy storage stacks S1 to S6 contains N energy storage cells 10. N is, for example, between 20 and 50. However, it is not limited to this, and N may be between 2 and 20, or greater than 50. N (the number of energy storage cells contained in one energy storage stack) can be set arbitrarily.

[0048] In each energy storage stack, the energy storage cells 10 are arranged within the lower case 100 such that the height direction is aligned with the Z direction, the width direction with the X direction, and the length direction with the Y direction. However, the N energy storage cells 10 are arranged such that the positional relationship between the electrode terminals 11 (positive terminal) and electrode terminals 12 (negative terminal) is reversed every two cells. In each energy storage stack, in the X direction, two energy storage cells 10 with electrode terminals 11 facing the +Y side and two energy storage cells 10 with electrode terminals 11 facing the -Y side are arranged alternately.

[0049] Energy storage stack S1 has terminal rows T1 and T2 in the X direction. Energy storage stack S2 has terminal rows T3 and T4 in the X direction. Energy storage stack S3 has terminal rows T5 and T6 in the X direction. Energy storage stack S4 has terminal rows T7 and T8 in the X direction. Energy storage stack S5 has terminal rows T9 and T10 in the X direction. Energy storage 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 arranged alternately in the X direction. Terminal rows T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, and T12 are arranged in this order from the -Y side to the +Y side.

[0050] Energy storage stacks S1 to S6 each contain the same number of energy storage cells, and are arranged so that the positions of the energy storage cells are aligned. As a result, six energy storage cells 10 aligned in the Y direction form a row (a row in the Y direction). These rows are then aligned in the X direction. 6 × N energy storage cells 10 are arranged in a matrix with 6 rows in the Y direction and N rows in the X direction. In the following, the energy storage cells 10 located at the 1st, 2nd, ..., and Nth positions from the -X end of energy storage stack S1 will be referred to as "cell 1(1)", "cell 1(2)", ..., and "cell 1(N)", respectively. In energy storage stack S2, the energy storage cells 10 located at the 1st, 2nd, ..., and Nth positions from the -X end will be referred to as "cell 2(1)", "cell 2(2)", ..., and "cell 2(N)", respectively. In energy storage stack S3, the first, second, ..., and Nth energy storage cells 10 from the -X end are denoted as "cell 3(1)", "cell 3(2)", ..., and "cell 3(N)", respectively. In energy storage stack S4, the first, second, ..., and Nth energy storage cells 10 from the -X end are denoted as "cell 4(1)", "cell 4(2)", ..., and "cell 4(N)", respectively. In energy storage stack S5, the first, second, ..., and Nth energy storage cells 10 from the -X end are denoted as "cell 5(1)", "cell 5(2)", ..., and "cell 5(N)", respectively. In energy storage stack S6, the first, second, ..., and Nth energy storage cells 10 from the -X end are denoted as "cell 6(1)", "cell 6(2)", ..., and "cell 6(N)", respectively.

[0051] Each energy cell included in the energy storage stack S1 to S6 shown in Figure 6 is electrically connected by the wiring pattern of the wiring board 200. The wiring board 200 has, for example, the wiring pattern shown in Figure 7. Figure 7 is a diagram showing an example of the configuration of the wiring board 200.

[0052] Referring to Figure 7, the wiring board 200 is, for example, a panel on which a wiring pattern is formed. Specifically, the wiring board 200 comprises a rectangular insulating substrate 201, 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 an insulating substrate. The insulating substrate 201 may contain a resin (for example, a thermosetting resin). The insulating substrate 201 corresponds to an example of a "substrate" according to this disclosure.

[0053] Each of the multiple conductor members 211 is connected to terminal row T1 or T2 shown in Figure 6, electrically connecting the energy storage cells included in the energy storage stack S1. Each of the multiple conductor members 212 is connected to terminal row T3 or T4 shown in Figure 6, electrically connecting the energy storage cells included in the energy storage stack S2. Each of the multiple conductor members 213 is connected to terminal row T5 or T6 shown in Figure 6, electrically connecting the energy storage cells included in the energy storage stack S3. Each of the multiple conductor members 214 is connected to terminal row T7 or T8 shown in Figure 6, electrically connecting the energy storage cells included in the energy storage stack S4. Each of the multiple conductor members 215 is connected to terminal row T9 or T10 shown in Figure 6, electrically connecting the energy storage cells included in the energy storage stack S5. Each of the multiple conductor members 216 is connected to terminal row T11 or T12 shown in Figure 6, electrically connecting the energy storage cells included in the energy storage stack S6.

[0054] Conductor member 221 electrically connects energy storage stacks S1 and S2. Conductor member 222 electrically connects energy storage stacks S3 and S4. Conductor member 223 electrically connects energy storage stacks S5 and S6. Conductor members 231, 232, 233, 234, 235, and 236 electrically connect energy storage stacks S1, S2, S3, S4, S5, and S6 to the battery circuit unit 30, respectively (see Figure 3).

[0055] Each of the conductor members 211-216, 221-223, and 231-236 is, for example, a metal plate-shaped member. Each of the conductor members 221-223 may be a U-shaped plate-shaped member. Each conductor member may also be a busbar. The material and shape of each conductor member are arbitrary.

[0056] In the example shown in Figure 7, each of the conductor members 211 to 216 connects two energy storage cells in parallel in the corresponding energy storage stack, and the resulting parallel connections (multiple energy storage cells connected in parallel) are connected in series. Conductor member 221 electrically connects the respective electrode terminals 11 of cell 1(1) and cell 1(2) to the respective electrode terminals 12 of cell 2(1) and cell 2(2). Conductor member 222 electrically connects the respective electrode terminals 11 of cell 3(1) and cell 3(2) to the respective electrode terminals 12 of cell 4(1) and cell 4(2). Conductor member 223 electrically connects the respective electrode terminals 11 of cell 5(1) and cell 5(2) to the respective electrode terminals 12 of cell 6(1) and cell 6(2). One end of conductor member 231 is connected to the respective electrode terminals 12 of cell 1(N-1) and cell 1(N), and the other end of conductor member 231 is connected to the battery circuit unit 30. One end of conductor member 232 is connected to the respective electrode terminals 11 of cell 2(N-1) and cell 2(N), and the other end of conductor member 232 is connected to the battery circuit unit 30. One end of conductor member 233 is connected to the respective electrode terminals 12 of cell 3(N-1) and cell 3(N), and the other end of conductor member 233 is connected to the battery circuit unit 30. One end of conductor member 234 is connected to the respective electrode terminals 11 of cell 4(N-1) and cell 4(N), and the other end of conductor member 234 is connected to the battery circuit unit 30. One end of conductor member 235 is connected to the respective electrode terminals 12 of cell 5(N-1) and cell 5(N), and the other end of conductor member 235 is connected to the battery circuit unit 30. One end of the conductor member 236 is connected to the respective electrode terminals 11 of cell 6(N-1) and cell 6(N), and the other end of the conductor member 236 is connected to the battery circuit unit 30. Furthermore, the battery circuit unit 30 shown in Figure 3 electrically connects cell 2(N) and cell 3(N), as well as cell 4(N) and cell 5(N). This electrically connects the energy storage stacks S1 to S6. In the pattern shown in Figure 7, multiple parallel connections are connected in series.

[0057] The connection configurations of the multiple energy storage cells are not limited to those shown in Figures 6 and 7, and can be changed as appropriate. For example, the number of energy storage cells connected in parallel may be three or more, rather than two. Alternatively, all energy storage cells may be connected in series without forming a parallel connection.

[0058] In this embodiment, the wiring pattern of the wiring board 200 is formed by the conductor members 211 to 216. The conductor members 211 to 216 are fixed to recesses formed on the surface (+Z side) of the insulating substrate 201. Parts of the conductor members 211 to 216 are embedded in the insulating substrate 201. However, it is not essential that recesses (steps) for the conductor members 211 to 216 be formed on the surface of the insulating substrate 201. The conductor members 211 to 216 may be bonded to a flat surface of the insulating substrate 201.

[0059] As shown in Figure 7, the insulating substrate 201 has a plurality of openings h21 (more specifically, "6 × N" openings h21). These openings h21 are located between the electrode terminals of each energy storage cell included in the energy storage stack S1 to S6, more specifically below the valve 13 (-Z side). Each opening h21 faces the valve 13 of the energy storage cell 10 in the Z direction. The openings h21 are, for example, elongated holes penetrating 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. Therefore, the openings h11 and h21 form a through hole h10 (see Figure 8 below) that penetrates the lower case 100 and the insulating substrate 201. The openings h11 and h21 may have the same shape and dimensions in the XY plane.

[0060] Each of the following regions has N openings h22 arranged in the X direction (see Figure 12 below). The openings h22 are formed in accordance with the positions of the energy storage cells 10. Each opening h22 is formed so that it is sandwiched between two adjacent energy storage cells 10 in the Y direction. The openings h22 are, for example, circular holes penetrating the insulating substrate 201. In the XY plane, the position of each of the multiple openings h22 corresponds to the position of each of the multiple openings h12 shown in Figure 4. The openings h12 and h22 form a through-hole h20 (Figure 3) that penetrates the lower case 100 and the wiring board 200. In this embodiment, the openings h12 and h22 have the same shape and dimensions in the XY plane. However, the embodiment is not limited to this, and the openings h12 and h22 may have different shapes and dimensions in the XY plane.

[0061] Each of the openings h21 and h22 is formed, for example, by punching or etching. As will be described in detail later, the insulating substrate 201 is given hydrophobicity by surface treatment, except for certain parts (see Figure 12). Opening h22 is located in a part that is not given hydrophobicity. The edge of opening h22 is relatively hydrophilic compared to the other parts.

[0062] The insulating substrate 201 is provided with cover members 241 to 246. This ensures that all openings h21 formed in the insulating substrate 201 are covered by the cover members 241 to 246. Each of the cover members 241 to 246 comprises a base material 202 that is elongated in the X direction, and N lid portions 202a arranged in the X direction. The base material 202 may have an adhesive on one side (the adhesive side). The base material 202 may be an adhesive tape, such as PP (polypropylene) tape. The N lid portions 202a are formed on the base material 202. In this embodiment, the lid portions 202a contain mica. Mica has excellent heat resistance and electrical insulation properties. The N lid portions 202a in the cover members 241 to 246 are each formed to cover N openings h21 located below the energy storage stacks S1 to S6. The position of the lid portions 202a is determined according to the position of the openings h21. The size of the lid portion 202a is the same as or larger than the opening h21. For example, N lid portions 202a may be formed on the base material 202 by attaching N mica foils to the adhesive surface of the base material 202. Alternatively, N lid portions 202a may be formed on the base material 202 by forming N through holes in the base material 202 and providing mica foil in each of these through holes. Cover members 241 to 246 are attached to the surface (+Z side) of the insulating substrate 201, for example, via the adhesive surface of the base material 202.

[0063] For example, after attaching cover members 241-246 to the insulating substrate 201, the energy storage stacks S1-S6 shown in Figure 6 are rotated 180° around the X-axis as the axis of rotation, and placed on the wiring board 200 with the surface F10 of each energy storage cell facing downwards in the vertical direction. Then, the energy storage stacks S1-S6 and the wiring board 200 are connected, and the connected energy storage stacks S1-S6 and wiring board 200 are placed inside the lower case 100. Furthermore, the battery circuit unit 30 is connected to the wiring board 200, and the cooling device 20 is placed inside the lower case 100. As a result, the inside of the lower case 100 is in the state shown in Figure 3. Of the cooling device 20, the cooler 22C may be placed inside the lower case 100 together with the energy storage stacks S1-S6. After that, the remaining part of the cooling device 20 may be placed inside the lower case 100, and the pipes 22A and 22B may be connected to the cooler 22C. Each of the wiring board 200 and the battery circuit unit 30 may be fixed to the lower case 100 with an adhesive (for example, silicone adhesive).

[0064] The wiring board 200 is electrically connected to the battery circuit unit 30, for example, as shown in the lower part of Figure 3. The battery circuit unit 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 terminal end of the entire energy storage stack S1 to S6 (all energy storage cells). The total negative terminal 32 is located at the negative terminal end of the entire energy storage stack S1 to S6 (all energy storage cells). Wire L1 electrically connects conductor member 232 and conductor member 233. Wire L2 electrically connects conductor member 234 and conductor member 235. A fuse 34 is provided on wire L2. 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. Conductor member 231 is connected to the total negative terminal 32. The wire L4 electrically connects the total negative terminal 32 to J / B33. J / B33 houses various electrical devices. J / B33 may include at least one of a relay, fuse, resistor, current sensor, and connector (e.g., a connector to an on-board charger). The battery circuit unit 30 may further include at least one of a BMS (Battery Management System) and an ECU (Electronic Control Unit). Area R5 (Figure 4) of the lower case 100 may further house various sensors (e.g., temperature sensors and voltage sensors) and signal lines that transmit the detected values ​​of each sensor to at least one of the BMS and ECU. Voltage sensors may be provided for each parallel connection or for each energy storage cell. The signal lines may be formed by an FPC (Flexible Printed Circuit Board).

[0065] The electrode terminals of the energy storage cell 10 and the conductor members of the wiring board 200 may be joined by crimping, heat pressing, or welding (e.g., laser welding). Alternatively, these electrode terminals and conductor members may be fastened together. A recess (countersink) for accommodating bolt heads and / or washers may be formed on the back surface (-Z side) of the insulating substrate 201.

[0066] Figures 8, 9, 10, and 11 are end views of the energy storage device B along lines VIII-VIII, IX-IX, XX, and XI-XI in Figure 3, respectively.

[0067] Referring to Figures 8 to 11, the upper cover 110 is joined to the upper surface (+Z side) of each of the side walls W1 to W4, for example, via adhesive 110b, and further fastened with bolts 110a. The shear panel 120 is joined to the lower surface (-Z side) of each of the side walls W1 to W4, for example, via adhesive 120b. An exhaust passage P1 is formed between the bottom wall 101 of the lower case 100 and the shear panel 120. Each of the side walls W1 to W4 is formed in a hollow shape. Exhaust passages P2 and P3 are formed inside the side walls W2 and W3, respectively. Although not shown, an exhaust passage is also formed inside the side wall W4 in a manner similar to the exhaust passage P3 of the side wall W3. These exhaust passages are in communication with each other. The adhesives 110b and 120b may be adhesives with a higher thermal conductivity than air (for example, silicone adhesives).

[0068] 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 penetrates 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 passage P2.

[0069] As shown in Figures 8 and 11, when the pressure inside the energy storage cell 10 exceeds a first reference value, valve 13 opens. Then, the pressure and heat of the gas discharged from inside the energy storage cell 10 through valve 13 create a hole in the cover portion 202a facing valve 13. The gas discharged from the energy storage cell 10 flows into the exhaust passage P1 through this hole. Each of the exhaust valves 151 and 152 shown in Figure 3 opens when the pressure in the exhaust passage P2 exceeds a second reference value. The second reference value may be a pressure value lower than the first reference value. For example, check valves are used for each of the exhaust valves 151 and 152. When at least one of the exhaust valves 151 and 152 opens, the gas in each exhaust passage flows toward the opened exhaust valve and is discharged to the outside of the energy storage device B through that exhaust valve. The thickness of the cover portion 202a provided on the wiring board 200 (Figure 7) is set to a thickness such that a hole is created when the opposing valve 13 opens (for example, when the valve opens in a way that causes ignition).

[0070] A mica layer 120a (e.g., mica foil) is provided on the inner (+Z side) surface of the shear panel 120. The mica layer 120a may be provided so as to overlap all of the lid portions 202a in the XY plane. The mica layer 120a may be provided over the entire region R5 shown in Figure 4. The mica layer 120a protects the shear panel 120 from substances (gas, electrolyte, debris, etc.) released from the energy storage cell 10 through the lid portions 202a.

[0071] As shown in Figure 10, a space V1 exists between the partition wall 103 and the side wall W1 within the lower case 100. Although not shown, the piping 21A shown in Figure 3 is located in space V1. As shown in Figures 8 and 9, a space V2 exists above the battery circuit unit 30 within the lower case 100. Although not shown, the cooling piping 23 shown in Figure 3 is located in space V2. As shown in Figure 11, a space V3 exists between the energy storage cell 10 located at the -Y end of the lower case 100 and the side wall W3. Although not shown, the piping 22A shown in Figure 3 is located in space V3. Spaces V1, V2, and V3 are located in regions R1, R2, and R3 (Figure 4) in the XY plane, respectively.

[0072] In each energy storage stack, an intermediate member 40 is provided between two adjacent energy storage cells 10 in the X direction, and a terminal member 40a is provided on the outside of the energy storage cell 10 located at the end in the X direction.

[0073] As shown in Figure 8, the intermediate member 40 is located, for example, between cell 3(N-1) and cell 3(N). The intermediate member 40 includes a cooler 22C (Figure 3), two insulating pads 41, and two shock absorbers 42 (only one is shown). Each of the two insulating pads 41 may be a resin film. In the intermediate member 40 shown in Figure 8, one insulating pad 41 is located between the cooler 22C and cell 3(N-1), and the other insulating pad 41 is located between the cooler 22C and cell 3(N). The shock absorbers 42 are located at both ends of the intermediate member 40 in the Z direction and suppress the transmission of shock to the cooler 22C. Figure 8 shows only the +Z end of the intermediate member 40, but the -Z end has a similar structure.

[0074] As shown in Figure 8, the terminal member 40a is located, for example, on the outside (+X side) of cell 3(N). The terminal member 40a includes a cooler 22C (Figure 3), an insulating pad 41, an insulating pad 41a, and two shock absorbers 42a (only one is shown). The terminal member 40a has basically the same structure as the intermediate member 40. However, in the terminal member 40a, one of the two insulating pads 41 in the intermediate member 40 is replaced with an insulating pad 41a that is formed thicker than the insulating pad 41. This makes it more difficult for shocks to be transmitted from the outside to the energy storage section (energy storage stack S1~S6). The shock absorbers 42a are located at both ends of the terminal member 40a in the Z direction and suppress the transmission of shocks to the cooler 22C. Figure 8 shows only the +Z side end of the terminal member 40a, but the -Z side end has a similar structure.

[0075] As shown in Figure 9, the partition wall 104 has an opening 104a through which the conductor member 232 passes. The conductor member 232 is connected to the battery circuit unit 30 through the opening 104a. Although not shown, the partition wall 104 also has openings through which each of the conductor members 231, 233, 234, 235, and 236 shown in Figure 3 passes.

[0076] Figure 12 is a diagram illustrating the cross-sectional structure of the wiring board 200. The end view along line XII-XII in the plan view of the wiring board 200 shown at the top of Figure 12 is shown at the bottom of Figure 12.

[0077] Referring to Figure 12, the insulating substrate 201 has a surface F1 facing the +Z side (the upper surface in the vertical direction) and a surface F2 facing the -Z side (the lower surface in the vertical direction). The entire surface F2 is formed flat. No conductive members are provided on surface F2. On the other hand, multiple conductive members (including conductive members 211-216 and 221-223) are formed on surface F1. Multiple recesses are also formed on surface F1. Recesses are formed between adjacent energy storage stacks in the Y direction on surface F1. Specifically, recesses (i.e., grooves) extending in the X direction are formed in each of Rs1-Rs5 in Figure 12. An opening h22 is formed within each recess.

[0078] The recess of Rs1 has a slope that descends from terminal row T2 towards the opening h22, and a slope that descends from terminal row T3 towards the opening h22. The recess of Rs2 has a slope that descends from terminal row T4 towards the opening h22, and a slope that descends from terminal row T5 towards the opening h22. The recess of Rs3 has a slope that descends from terminal row T6 towards the opening h22, and a slope that descends from terminal row T7 towards the opening h22. The recess of Rs4 has a slope that descends from terminal row T8 towards the opening h22, and a slope that descends from terminal row T9 towards the opening h22. The recess of Rs5 has a slope that descends from terminal row T10 towards the opening h22, and a slope that descends from terminal row T11 towards the opening h22. The formation of these slopes allows water on surface F1 to be guided by gravity to the opening h22, and to easily fall through the opening h22 into the exhaust passage P1 (Figures 8 to 11).

[0079] The insulating substrate 201 has a hydrophilic portion 201a (first portion) located at the edge of each of the multiple openings h22, and a hydrophobic portion (second portion) that is more hydrophobic 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. Hydrophobicity can be expressed, for example, by the contact angle. The larger the contact angle, the higher the hydrophobicity. The hydrophilic portion 201a and the hydrophobic portion of the insulating substrate 201 may be formed by selectively applying a water-repellent treatment to the portion corresponding to the hydrophobic portion (the portion excluding the edges of the openings h22). The water-repellent treatment may be a process of coating the surface F1 of the insulating substrate 201 with silicone or fluorine. By providing the hydrophilic portion 201a at the edge of the openings h22, water on the surface F1 is guided to the edge of the openings h22, making it easier for it to fall through the openings h22 into the exhaust passage P1 (Figures 8 to 11).

[0080] Figure 13 is an end view of the energy storage device B along line XIII-XIII in Figure 3.

[0081] Referring to Figures 3 to 12 and Figure 13, the energy storage device B comprises two adjacent energy storage cells 10 (for example, cell 1(6) and cell 2(6)) 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 conductor member 212 (second conductor member) provided on 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 surface F10 (the lower surface in the vertical direction). 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 surface F10 (the lower surface in the vertical direction). Furthermore, in the insulating substrate 201, a recess R10 and an opening h22 are provided 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 the electrode terminal 11 of cell 1(6) and the electrode terminal 12 of cell 2(6). An opening h22 is formed within the recess R10. The opening h22 may be located midway between the electrode terminal 11 of cell 1(6) and the electrode terminal 12 of cell 2(6). An opening h12 is formed in the bottom wall 101 of the lower case 100 (see Figure 4). The opening h12 is located below (-Z side) the opening h22. The opening h22 communicates with the exhaust passage P1 through the opening h12. The openings h12 and h22 are connected in the Z direction and form a through hole h20.

[0082] The insulating substrate 201 has a first inclined portion F11 that slopes downward toward the -Z side toward the opening h22 from the electrode terminal 11 of cell 1(6), and a second inclined portion F12 that slopes downward toward the -Z side toward the opening h22 from the electrode terminal 12 of cell 2(6). The insulating substrate 201 is located vertically below (-Z side) the respective surfaces F10 (including the valve 13) of cell 1(6) and cell 2(6). The exhaust passage P1 is located vertically below (-Z side) the insulating substrate 201.

[0083] Even if water (for example, water droplets W shown in Figure 13) is generated in at least one of the adjacent energy storage cells, cell 1(6) and cell 2(6), the water falls through the through-hole h20 into the exhaust passage P1. This prevents the water from spreading to the other energy storage cell even if water is generated in one of the adjacent energy storage cells, cell 1(6) and cell 2(6). In addition, the gas discharged from each of cell 1(6) and cell 2(6) flows through the exhaust passage P1 (see Figure 8). Therefore, the water in the exhaust passage P1 is discharged to the outside along with the gas through the exhaust valves 151 and 152.

[0084] Hereinafter, a pair of adjacent energy storage cells 10 (first energy storage cell and second energy storage cell) in the Y direction will be referred to as a "Y-cell pair". In this embodiment, as shown in Figure 3, the energy storage device B has "5 × N" Y-cell pairs. In each of the energy storage stacks S2 to S5, one energy storage cell 10 constitutes two Y-cell pairs. For example, cell 2(1) constitutes a Y-cell pair together with cell 1(1), while also constituting a Y-cell pair with cell 3(1). Of the "5 × N" Y-cell pairs, all but three Y-cell pairs connected by one of the conductor members 221, 222, and 223 have the structure shown in Figure 13.

[0085] The shape of the recess located between two adjacent energy storage cells 10 on the substrate is not limited to the shape shown in Figure 13 and can be changed as appropriate. Figure 14 shows a modified example of the recess R10 shown in Figure 13. The insulating substrate 201A shown in Figure 14 has a recess R10A instead of a recess R10 (Figure 13) which has an inclined side wall. The recess R10A has a bottom surface and a side wall perpendicular to the bottom surface. The recess R10A is located between the electrode terminals of a Y-cell pair, for example, between the electrode terminal 11 of cell 1(6) and the electrode terminal 12 of cell 2(6). The recess R10 or R10A may be formed from one end to the other of the insulating substrate 201 in the X direction. However, it is not limited to this, and the side wall of the recess may be formed to surround one or more openings h22 (for example, on all four sides).

[0086] It is not essential that a recess be formed between two adjacent energy storage cells 10 on the substrate. Figure 15 shows an example where there is no recess between two adjacent energy storage cells 10 on the substrate. The front and back surfaces (faces F1 and F2) of the insulating substrate 201B shown in Figure 15 are formed flat. The opening h22 that penetrates the insulating substrate 201B between the electrode terminals of the Y-cell pair, together with the opening h12 that penetrates the bottom wall 101 of the lower case 100 below it, forms a through hole h20.

[0087] Multiple through holes may be formed between two adjacent energy storage cells 10 on the substrate. Figure 16 shows an example in which multiple through holes are formed between two adjacent energy storage cells 10 on the substrate. Five openings h22 are formed within the 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 that penetrates the bottom wall 101 of the lower case 100 below it, forms a through hole h20. The energy storage device shown in Figure 16 has five through holes h20 that communicate with the exhaust passage P1. In addition, hydrophilic portions 201a are provided on the edges of the five openings h22. The number of openings h22 located between the electrode terminals of the Y-cell pair can be changed as appropriate, and may be two to four or six or more.

[0088] In the above embodiment, openings h22 are formed for all Y-cell pairs (see Figures 7 and 12). This increases the design flexibility of the wiring pattern on the insulating substrate 201. However, the embodiment is not limited to this, and openings h22 may be formed only for predetermined Y-cell pairs. For example, openings h22 do not need to be formed below each of the conductor members 221, 222, and 223.

[0089] Figure 17 shows a first modified example of an opening located between two adjacent energy storage cells 10 on a substrate. In the insulating substrate 201D shown in Figure 17, each of the multiple openings h22A is formed across multiple Y-cell pairs. The dimension in the X direction is longer for opening h22A than for opening h22 shown in Figure 7. The opening h22A is formed in a slit shape and has an X-direction dimension corresponding to three energy storage cells 10. Note that the X-direction dimension of the opening on the substrate can be changed as appropriate, and may be a dimension corresponding to two energy storage cells 10, or a dimension corresponding to four or more energy storage cells 10.

[0090] Figure 18 shows a second modified example of an opening located between two adjacent energy storage cells 10 on the substrate. In the insulating substrate 201E shown in Figure 18, each of the multiple openings h22B is formed across the entire energy storage stack. The opening h22B has dimensions from one end to the other of the energy storage stack in the X direction. Long openings h22B formed in the X direction are arranged one at a time between adjacent energy storage stacks.

[0091] A cooler may be provided on the substrate. Figure 19 shows an example of a substrate with a cooler. One or more coolers 50 are provided on the surface F2 (the vertically lower surface) of the insulating substrate 201F shown in Figure 19. A cooler 50 may be provided for each energy storage stack. The insulating substrate 201F comprises, for example, six coolers 50 (only two are shown) formed in an elongated shape in the X direction. The coolers 50 are fixed in recesses formed on the surface F2 of the insulating substrate 201F. The coolers 50 are partially embedded in the insulating substrate 201F. Part of the cooler 50 is located near a through hole h20. The coolers 50 cool the area around the valve 13 in the Y-cell pair and the gas discharged from the valve 13 (for example, the gas in the exhaust passage P1).

[0092] A water-absorbing material may be provided between the opening h22 formed in the insulating substrate 201 and the exhaust passage P1 located below it. Figure 20 shows an example of a substrate with a water-absorbing material provided. In the example shown in Figure 20, a planar water-absorbing material 60 is provided on the outer surface (-Z side surface) of the bottom wall 101 of the lower case 100. The water-absorbing material 60 is located below the through-hole h20 so as to block the through-hole h20. The water-absorbing material 60 has water-absorbing properties and absorbs water that falls from the surface F1 of the insulating substrate 201 into the through-hole h20. The water absorbed by the water-absorbing material 60 volatilizes due to wind and / or heat from the fluid flowing in the exhaust passage P1. If the amount of water falling into the water-absorbing material 60 exceeds the water-holding limit of the water-absorbing material 60, the water that was not absorbed by the water-absorbing material 60 falls into the exhaust passage P1. By providing the water-absorbing material 60, the amount of water that falls into the exhaust passage P1 can be reduced. The absorbent material 60 may include fibers that absorb moisture by capillary action (for example, polyester fibers). The absorbent material 60 may also include fabric that has been treated for water absorption and quick drying.

[0093] Instead of or in addition to the through-hole h20, a protrusion may be provided on the substrate.

[0094] Figure 21 shows a first example in which a protrusion is provided between two adjacent energy storage cells 10 on a substrate. The insulating substrate 201G and bottom wall 101A shown in Figure 21 do not have the aforementioned through-hole h20 formed thereon. The protrusion M1 is fixed on the surface F1 of the insulating substrate 201G. The protrusion M1 may be welded or bonded to the insulating substrate 201G, or it may be fastened to the insulating substrate 201G. Alternatively, the protrusion M1 may be formed integrally 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 may be treated with a water-repellent coating. The height of the protrusion M1 is higher than the respective surfaces F10 of cells 1(6) and 2(6) that constitute the Y-cell pair. The top of the protrusion M1 is located on the +Z side of these surfaces F10. The presence of the protrusion M1 between the electrode terminals of adjacent cells 1(6) and 2(6) prevents water from spreading to the other energy storage cell even if water is generated in one of the cells. This makes it less likely for the electrode terminals of adjacent energy storage cells to short-circuit.

[0095] In the example shown in Figure 21, one protrusion M1 is provided between the electrode terminals of the Y-cell pair. However, the number of protrusions provided between the electrode terminals of the Y-cell pair can be changed as appropriate; it may be two to five, or six or more.

[0096] Figure 22 shows a second example in which a protrusion is provided between two adjacent energy storage cells 10 on a substrate. In the example shown in Figure 22, the protrusions M21 and M22 are fixed on the surface F1 of the insulating substrate 201B shown in Figure 15. In addition, a through hole h20 is provided between the protrusions M21 and M22 in the Y direction. These protrusions M21, M22, and the through hole h20 prevent short circuits between the electrode terminals of adjacent cells 1(6) and 2(6). Note that the protrusions M21 and M22 and the insulating substrate 201B may be formed separately and joined, or they may be formed seamlessly and integrally.

[0097] In the above embodiment, openings for passing conductor members 231 to 236 are formed in the partition wall 104 (see Figure 9). However, the embodiment is not limited to this, and the partition wall 104 may be divided. Figure 23 shows a modified example of the partition wall. The partition wall 104A shown in Figure 23 is composed of a plurality of partition plates. Partition plates are not provided in the portion corresponding to conductor members 231 to 236. Conductor members 231 to 236 can traverse in the X direction between the partition plates arranged in the Y direction. Alternatively, wires (e.g., cables) connected to the wiring board 200 may be connected to the battery circuit unit 30 by passing over the partition wall 104 shown in Figure 3. An equipment cooler (including cooling piping 23) for cooling the battery circuit unit 30 may be provided below the battery circuit unit 30. It is not essential that a cell cooler (e.g., cooler 22C) for cooling the energy storage cells be placed between adjacent energy storage cells. The cell cooler may be provided above the energy storage cells. The cell cooler may be provided to cover the top surface of all energy storage cells. Note that the partition walls 103 and 104 shown in Figure 3 are not essential components. At least one of the partition walls 103 and 104 may be omitted. Also, at least one of the exhaust valves 151 and 152 may be omitted. The gas flowing through each exhaust passage may be discharged to the outside of the energy storage device B through an exhaust port (e.g., exhaust port 151a). The discharged gas may be guided to a predetermined location by a duct provided outside the housing of the energy storage device B.

[0098] The various features of the energy storage device described above (each feature described in the embodiments and modifications) may be applied in any combination.

[0099] The use of the energy storage device is arbitrary. The energy storage device may be used in vehicles other than automobiles (electric motorcycles, electric wheelchairs, railway vehicles, ships, airplanes, electric vertical take-off and landing aircraft (eVTOLs), amphibious aircraft, etc.), mobile machinery (agricultural machinery, construction machinery, etc.), unmanned mobile vehicles (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.).

[0100] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0101] 1 Vehicle, 10 Energy storage cell, 11,12 Electrode terminals, 13 Valve, 50 Cooler, 60 Water absorbent material, 100 Lower case, 101,101A Bottom wall, 102 Peripheral wall, 110 Upper cover, 120 Share panel, 200 Wiring board, 201,201A~201G Insulating substrate, 211~216 Conductor member, B Energy storage device, h21,h22 Opening, h20 Through hole, M1,M21,M22 Protrusion, P1 Exhaust passage, S1~S6 Energy storage stack.

Claims

1. A power storage device comprising a first power storage cell, a second power storage cell, and a wiring board, The aforementioned wiring board comprises a substrate and a plurality of conductor members provided on the vertically upper surface of the substrate. The plurality of conductor members include a first conductor member and a second conductor member, The first energy storage cell has a first electrode terminal connected to the first conductor member on its vertically downward surface, The second energy storage cell has a second electrode terminal connected to the second conductor member on its vertically downward surface, An energy storage device wherein at least one of a protrusion, a recess, and a through hole is provided between the first electrode terminal and the second electrode terminal of the substrate.

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

3. The energy storage device according to claim 2, wherein the substrate has one or more first portions located at the edges of one or more through holes, and a second portion having a higher degree of hydrophobicity than the first portions.

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

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

7. The energy storage device according to claim 6, wherein a water-absorbing material is provided between the one or more through holes and the exhaust passage.

8. Each of the first and second energy storage cells is further provided with an explosion-proof valve on its vertically lower surface. The substrate is located vertically below the explosion-proof valves of the first and second energy storage cells, The exhaust passage is located vertically below the substrate. The energy storage device according to claim 6, wherein a cooler is provided on the vertically lower surface of the substrate.

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

Images