Energy storage device

Abstract

To provide a power storage device in which an electric wire can be arranged by efficiently using a space.SOLUTION: A power storage device includes a power storage element row 10 and an electric wire holding member 401. Each of the multiple power storage elements has a first terminal 141 and a gas exhaust valve 131. The electric wire holding member includes a first holding part 410, a second holding part 420, and a third holding part 430. The first holding part extends from a first end 10a to a second end 10b of the power storage element row. The second holding part extends toward the first end from the second end of the power storage element row. The third holding part connects the first holding part and the second holding part in the X-axis direction. The first holding part is located in a first area 810 between the multiple gas exhaust valves and the multiple first terminals. The second holding part is located in a second area 820 on the opposite side of the first area with the multiple gas exhaust valves held therebetween. The third holding part is located at a position that does not overlap the multiple gas exhaust valves.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to an electricity storage device including an electricity storage element array having a plurality of electricity storage elements. Background Art

[0002] Patent Document 1 discloses a battery module including a single cell group formed by arranging a plurality of single cells, and a wiring module attached to the single cell group. On the upper surface of the single cell, positive and negative electrode terminals are formed at positions close to both ends in the longitudinal direction. The wiring module includes a plurality of metal bus bars connected to electrode terminals of adjacent single cells, a temperature detection member that detects the temperature of the bus bars, and an insulating protector made of an insulating material that holds the bus bars and the temperature detection member. A plurality of bus bar holding portions are provided in two parallel rows on the insulating protector. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2016-122577 Summary of the Invention Problems to be Solved by the Invention

[0004] In the conventional battery module described above, the insulating protector is provided with a pair of wire accommodating grooves between two rows of busbar holders for accommodating wires connected to the busbars and wires connected to the temperature sensing element. The wires housed in the pair of wire accommodating grooves are bundled above the end cell (energy storage element) in the cell group (array of energy storage elements) and led to the outside of the battery module. Generally, a gas release valve, which opens when the internal pressure of the energy storage element rises, is provided on the surface where the electrode terminals of the energy storage element are located. Therefore, according to the configuration of the conventional battery module described above, a part of the insulating protector and several wires are located opposite the gas release valve of the end energy storage element. As a result, when the gas release valve is opened, the gas release may be obstructed by a part of the insulating protector and several wires. To solve this problem, it is conceivable to remove one of the pair of wire accommodating grooves, but in this case, it becomes difficult to obtain information (such as temperature) from the part close to that groove via the wires.

[0005] This invention was made by the present inventors by newly focusing on the above-mentioned problems, and aims to provide an energy storage device that allows for efficient use of space to arrange power lines. [Means for solving the problem]

[0006] A power storage device according to one aspect of the present invention comprises a power storage element array having a plurality of power storage elements arranged in a first direction, and a wire holding member for holding one or more wires, the wire holding member being arranged opposite to the power storage element array in a second direction intersecting the first direction, each of the plurality of power storage elements having a terminal and a gas discharge valve arranged in the second direction, and the wire holding member having a first holding portion extending from one end which is one end of the power storage element array in the first direction to the other end which is the other end of the power storage element array, and the other The device has a second retaining portion extending from one end toward the other end, and a third retaining portion connecting the first retaining portion and the second retaining portion in a third direction intersecting the first and second directions. The first retaining portion is located in a first region between the plurality of gas exhaust valves and the plurality of terminals when viewed from the second direction, the second retaining portion is located in a second region opposite to the first region, sandwiching the plurality of gas exhaust valves when viewed from the second direction, and the third retaining portion is positioned so as not to overlap with the plurality of gas exhaust valves when viewed from the second direction. [Effects of the Invention]

[0007] According to the energy storage device of the present invention, power lines can be arranged using space efficiently. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the configuration of an energy storage device according to an embodiment. [Figure 2] Figure 2 is a perspective view showing the configuration of the energy storage element array and wiring unit according to the embodiment. [Figure 3] Figure 3 is an exploded perspective view of the energy storage element array according to the embodiment. [Figure 4] Figure 4 is a perspective view showing the configuration of an energy storage element according to an embodiment. [Figure 5] Figure 5 is an exploded perspective view of the wiring unit according to the embodiment. [Figure 6] Figure 6 is a schematic plan view showing the wiring unit and its surrounding configuration according to the embodiment. [Figure 7] Figure 7 is a schematic cross-sectional view showing the wiring unit and its surrounding configuration according to the embodiment. [Figure 8] Figure 8 is a schematic plan view showing the configuration of a wiring unit and its surroundings according to a modified embodiment. [Modes for carrying out the invention]

[0009] (1) An energy storage device according to one aspect of the present invention comprises: an array of energy storage elements having a plurality of energy storage elements arranged in a first direction; and a wire holding member for holding one or more wires, the wire holding member being arranged opposite to the array of energy storage elements in a second direction intersecting the first direction, each of the plurality of energy storage elements having a terminal and a gas discharge valve arranged in the second direction, and the wire holding member having a first holding portion extending from one end which is one end of the array of energy storage elements in the first direction to the other end which is the other end of the array of energy storage elements, and in front of the array of energy storage elements The device has a second holding portion extending from one end toward the other end, and a third holding portion connecting the first holding portion and the second holding portion in a third direction intersecting the first and second directions. The first holding portion is located in a first region between the plurality of gas exhaust valves and the plurality of terminals when viewed from the second direction, the second holding portion is located in a second region opposite to the first region, sandwiching the plurality of gas exhaust valves when viewed from the second direction, and the third holding portion is positioned so as not to overlap with the plurality of gas exhaust valves when viewed from the second direction.

[0010] In this configuration, when viewed from a second direction, the first holding portion of the wire holding member is positioned in the first region, and the second holding portion of the wire holding member is positioned in the second region, opposite to the first region, with a plurality of gas discharge valves arranged in the first direction in between. Therefore, information about the other end of the energy storage element array in the second region or its vicinity can be obtained from one end of the energy storage element array in the first region via the wires held by the wire holding member. Furthermore, the first, second, and third holding portions of the wire holding member are all positioned so as not to overlap with any of the plurality of gas discharge valves when viewed from a second direction. Therefore, when gas is discharged from any of the plurality of gas discharge valves, the wire holding member and one or more wires are unlikely to obstruct the discharge of gas. Thus, the energy storage device according to this embodiment is an energy storage device that can arrange wires using space efficiently.

[0011] (2) In the energy storage device described in (1) above, a first energy storage element located at one end of the array of energy storage elements has a first thermistor positioned in a location included in the first region when viewed from the second direction, a second energy storage element located at the other end of the array of energy storage elements has a second thermistor positioned in a location included in the second region when viewed from the second direction, and the one or more wires may include a first wire electrically connected to the first thermistor and a second wire electrically connected to the second thermistor.

[0012] With this configuration, even if the first and second thermistors are positioned at different locations in the third direction, the first and second wires can be drawn together from one end of the energy storage element array in the first direction and one end in the third direction. Therefore, even if the first and second thermistors must be positioned at different locations in the third direction due to the number of energy storage elements included in the energy storage element array or the electrical connection configuration (such as the selection of parallel and series connections), the first and second wires can be efficiently arranged.

[0013] (3) In the power storage device according to (1) or (2) above, the power storage element row may include a spacer disposed between two adjacent power storage elements among the plurality of power storage elements, and the third holding portion may be disposed at a position overlapping the spacer when viewed from the second direction.

[0014] According to this configuration, the third holding portion is disposed using the space in the positive Z-axis direction of the spacer for protecting at least one power storage element or improving the stability of the position thereof. This is advantageous from the perspective of efficiently using space to arrange electric wires.

[0015] (4) In the power storage device according to any one of (1) to (3) above, the power storage element row may include a spacer disposed at the one end portion or the other end portion in the first direction, and the third holding portion may be disposed at a position overlapping the spacer when viewed from the second direction.

[0016] According to this configuration, the third holding portion is disposed using the space in the positive Z-axis direction of the spacer for protecting the power storage element at the end portion in the first direction of the power storage element row or improving the position stability thereof. This is advantageous from the perspective of efficiently using space to arrange electric wires.

[0017] (5) The power storage device according to any one of (1) to (4) above may further include a bus bar joined to terminals of two or more of the plurality of power storage elements, and a bus bar holder that holds the bus bar, wherein the electric wire holding member is a member that forms a groove for accommodating the one or more electric wires, and is disposed spaced apart from the bus bar holder.

[0018] According to this configuration, the arrangement position, size, or shape of the electric wire holding member can be set to an arrangement position, size, or shape suitable for the wiring layout of electric wires, regardless of the arrangement position, size, or shape of the bus bar holder.

[0019] (6) The power storage device according to any one of (1) to (5) above, wherein the first holding portion may have an opening from which an end portion of the one or more electric wires protrudes, the opening being disposed at an end portion of the first holding portion on one side in the first direction.

[0020] According to this configuration, the one or more electric wires are drawn out of the wire holding member through the opening. Therefore, even when the number of electric wires is increased, those electric wires can be easily handled as a single bundle of wires.

[0021] (7) The power storage device according to any one of (1) to (6) above, wherein the third holding portion may connect an end portion of the first holding portion on the other side in the first direction and an end portion of the second holding portion on one side in the first direction.

[0022] According to this configuration, the length of each of the first holding portion and the second holding portion in the first direction can be set to a length that does not cover the entire region of the power storage element array in the first direction. Therefore, when viewed from the second direction, a relatively large amount of space (gap) that enables inspection of the power storage element array by visual observation or image processing can be secured.

[0023] Hereinafter, a power storage device according to an embodiment of the present invention (including modifications thereof) will be described with reference to the drawings. All of the embodiments described below are illustrative of comprehensive or specific examples. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, manufacturing steps, order of manufacturing steps, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. Dimensions and the like are not strictly illustrated in each drawing. In each drawing, the same or similar constituent elements are denoted by the same reference numerals.

[0024] In the following description and drawings, the direction in which a pair of terminals on an energy storage element are aligned, or the direction in which a pair of short sides of the energy storage element's container face each other, is defined as the X-axis direction. The direction in which a pair of long sides of the energy storage element's container face each other, the thickness direction (flattening direction) of the energy storage element's container, the direction in which multiple energy storage elements or multiple spacers in an energy storage element array are aligned, or the direction in which energy storage elements and spacers in an energy storage element array are aligned, is defined as the Y-axis direction. The direction in which the terminals of an energy storage element protrude, the direction in which the body of the energy storage element's container and the lid plate are aligned, the direction in which the case body and the lid of the case are aligned, the direction in which the energy storage element array and the wiring unit are aligned, or the vertical direction is defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect (orthogonal in this embodiment) with each other. Depending on the usage, the Z-axis direction may not be the vertical direction, but for the sake of explanation below, the Z-axis direction will be described as the vertical direction.

[0025] In the following explanation, the X-axis positive direction refers to the direction of the X-axis arrow, and the X-axis negative direction refers to the opposite direction. When simply referring to the X-axis direction, it refers to either the X-axis positive direction or the X-axis negative direction, or both directions. When referring to one side and the other side of the X-axis direction, it refers to one and the other of the X-axis positive direction and the X-axis negative direction. The same applies to the Y-axis direction and the Z-axis direction. Expressions indicating relative directions or orientations, such as parallel and orthogonal, include cases where they are not strictly those directions or orientations. For example, when two directions are orthogonal, it means not only that the two directions are perfectly orthogonal, but also that they are substantially orthogonal, i.e., that they include a difference of, for example, a few percent. In the following explanation, when the term "insulation" is used, it means "electrical insulation".

[0026] (Embodiment) [1. General explanation of energy storage devices] First, the general configuration of the energy storage device 1 according to this embodiment will be described. Figure 1 is a perspective view showing the configuration of the energy storage device 1 according to this embodiment. In Figure 1, the lid 320 has been removed from the case body 310 of the energy storage device 1, and the energy storage element array 10 and the wiring unit 400 have been removed from the case body 310. Figure 2 is a perspective view showing the configuration of the energy storage element array 10 and the wiring unit 400 according to this embodiment. In Figure 2, the wiring unit 400 has been separated from the energy storage element array 10. In Figures 1 and 2, the illustration of one or more electric wires 500 (described later using Figure 5, etc.) that are partially pulled out and arranged from the wiring unit 400 is omitted. Figure 3 is an exploded perspective view of the energy storage element array 10 according to this embodiment. In Figure 3, the components of the energy storage element array 10 are exploded in the arrangement direction (Y-axis direction), and four energy storage elements 100 and seven spacers 200 are shown. In Figures 1, 2, and Figure 5 (described later), the connection portion 490 that connects the wire holding member 401 and the busbar holder 480 is not shown. The connection portion 490 will be described later using Figure 6.

[0027] The energy storage device 1 is a device that can charge electricity from an external source and discharge electricity to an external source. The energy storage device 1 is used for power storage or power supply purposes. The energy storage device 1 is used as a battery for driving or starting the engine of mobile vehicles such as automobiles, motorcycles, watercraft, ships, snowmobiles, agricultural machinery, construction machinery, or railway vehicles for electric railways. Examples of automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicles. Examples of railway vehicles for electric railways include electric trains, monorails, maglev trains, and hybrid trains equipped with both diesel engines and electric motors. The energy storage device 1 can also be used as a stationary battery for household or commercial use.

[0028] As shown in Figure 1, the energy storage device 1 comprises an array of energy storage elements 10, a wiring unit 400, and a case 300 that houses the array of energy storage elements 10 and the wiring unit 400. The energy storage device 1 also includes external terminals (positive external terminal and negative external terminal) for electrical connection to external devices, but their illustration and description are omitted. In addition to the above components, the energy storage device 1 may also include a circuit board and electrical equipment such as relays for monitoring or controlling the charge and discharge states of the array of energy storage elements 10.

[0029] The energy storage element array 10 is a battery module (battery pack) having a plurality of energy storage elements 100. The energy storage element array 10 has a roughly rectangular parallelepiped shape that is long in the Y-axis direction, as the plurality of energy storage elements 100 are arranged alternately with spacers 200 in the Y-axis direction (first direction). The energy storage element array 10 has a plurality of energy storage elements 100 and a plurality of spacers 200 (200a, 200b, and 200c). The plurality of energy storage elements 100 included in the energy storage element array 10 are electrically connected by a plurality of busbars 380 (described later using Figure 5). In this embodiment, the plurality of busbars 380 are held in a busbar holder 480 which is part of a wiring unit 400. In this embodiment, the energy storage element array 10 is an unconstrained type module that does not have restraining members (end plates and side plates, etc.) that restrain the plurality of energy storage elements 100 and spacers 200 in the Y-axis direction. The energy storage element array 10 may be restrained in the Y-axis direction by restraining members.

[0030] The energy storage element 100 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 100 has a flattened rectangular parallelepiped shape (square, prism) in the Y-axis direction. In this embodiment, multiple energy storage elements 100 are arranged in line in the Y-axis direction, but the number of energy storage elements 100 arranged is not particularly limited; it may be one, several dozen, or more. The size and shape of the energy storage element 100 are also not particularly limited; it may be an elongated cylindrical shape, an elliptical cylindrical shape, a cylindrical shape, a polygonal prism shape other than a rectangular parallelepiped, etc. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery; it may be a secondary battery other than a non-aqueous electrolyte secondary battery, or it may be a capacitor. The energy storage element 100 may be a primary battery instead of a secondary battery. The energy storage element 100 may be a battery using a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element.

[0031] The spacer 200 is a flattened member in the Y-axis direction, positioned alongside the energy storage element 100 in the Y-axis direction, and insulating and / or heat-insulating the energy storage element 100 from other members. The spacer 200 is an insulating or heat-insulating plate positioned in the positive or negative Y-axis direction of the energy storage element 100, and insulating and / or heat-insulating the energy storage elements 100 from each other or from the energy storage element 100 to the case 300. The spacer 200 has walls on both the X-axis and Z-axis sides of the energy storage element 100, and thus functions as a holder that holds the energy storage element 100 and positions the energy storage element 100.

[0032] Spacer 200 is formed from insulating materials such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyetheretherketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or composite materials thereof, or from insulating materials such as mica.

[0033] All spacers 200 (spacers 200a, 200b, and 200c) may be made of the same material, or any of the spacers 200 may be made of a different material.

[0034] Hereafter, the spacer 200 positioned at the center of the energy storage element array 10 in the Y-axis direction (between the two energy storage elements 100 at the center) will also be referred to as spacer 200b. The spacers 200 positioned at both ends of the energy storage element array 10 in the Y-axis direction (between the end energy storage elements 100 and the case 300) will also be referred to as spacer 200c. The spacer 200 positioned between spacer 200b and spacer 200c (between the two energy storage elements 100 other than the center) will also be referred to as spacer 200a.

[0035] As shown in Figure 3, spacer 200a is an intermediate spacer (intermediate holder) that has walls on both the X-axis and Z-axis sides of two energy storage elements 100 arranged on both sides of spacer 200a in the Y-axis direction, and holds the two energy storage elements 100. Similarly, spacer 200b is a center spacer (center plate or center holder) that has walls on both the X-axis and Z-axis sides of two energy storage elements 100 arranged on both sides of spacer 200b in the Y-axis direction, and holds the two energy storage elements 100. Spacer 200b has the function of increasing the rigidity of the energy storage element row 10 which is long in the Y-axis direction. Spacer 200c is an end spacer (end holder) that has walls on both the X-axis and Z-axis sides of one energy storage element 100 arranged in the Y-axis positive or Y-axis negative direction of spacer 200c, and holds the one energy storage element 100.

[0036] Each of these multiple spacers 200 has a spacer body 210 facing the energy storage element 100 in the Y-axis direction, and a pair of protrusions 250 provided at the Z-axis positive end of the spacer body 210. Each of the pair of protrusions 250 protrudes from the spacer body 210 in the Z-axis positive direction and is spaced apart from each other in the X-axis direction. In the energy storage element array 10, as the multiple spacers 200 are arranged in the Y-axis direction, the pairs of protrusions 250 of the multiple spacers 200 are connected in the Y-axis direction, as shown in Figure 2. As a result, the multiple protrusions 250 connected in the Y-axis direction form wall portions 250A and wall portions 250B that are spaced apart from each other in the X-axis direction. Each of the multiple protrusions 250 included in wall portions 250A and 250B has a projection 254 that protrudes in the X-axis direction, as shown in Figure 2. One or more of these multiple protrusions 254 are hooked onto a part of the wiring unit 400, thereby attaching the wiring unit 400 to the energy storage element array 10.

[0037] The case 300 is a roughly rectangular parallelepiped (box-shaped) container that constitutes the outer casing (shell) of the energy storage device 1. The case 300 is positioned outside the energy storage element array 10, fixing the energy storage element array 10 in a predetermined position and protecting it from impacts, etc. The case 300 is a metal case formed from a metal component such as aluminum, aluminum alloy, stainless steel, iron, or plated steel sheet. In this embodiment, the case 300 is formed from die-cast aluminum (aluminum die-cast). The case 300 may also be formed from an insulating material such as any resin material that can be used for the spacer 200 of the energy storage element array 10.

[0038] As shown in Figure 1, the case 300 has a case body 310 that constitutes the main body of the case 300, and a cover 320 that closes the opening 310a of the case 300. The case body 310 is a housing (enclosure) with an opening 310a formed in the positive Z-axis direction. The case body 310 houses the energy storage element array 10 to which the wiring unit 400 is attached. The cover 320 is a flat rectangular member that closes the opening 310a of the case body 310. After the energy storage element array 10 is inserted into the case body 310 through the opening 310a, the case body 310 and the cover 320 are joined together by bolts, welding, adhesive, etc.

[0039] The lid 320 is provided with a gas outlet 321, as shown in Figure 1. When gas is discharged from any of the energy storage elements 100 included in the energy storage element array 10, the gas is discharged to the outside of the case 300 through the gas outlet 321. The gas outlet 321 may be formed in the case body 310 instead of the lid 320.

[0040] The case body 310 or the lid 320 may be fitted with a terminal block on which external terminals (positive external terminal and negative external terminal) are arranged.

[0041] The wiring unit 400 includes a wire holding member 401 that holds one or more wires 500. The wiring unit 400 is positioned opposite the energy storage element array 10 in the Z-axis direction. More specifically, the wiring unit 400 is positioned opposite the energy storage element array 10 in the Z-positive direction of the energy storage element array 10. The wire holding member 401 has a first holding portion 410, a second holding portion 420, and a third holding portion 430. As shown in Figures 1 and 2, the first holding portion 410 extends from the Y-minus end (one end) in the Y-axis direction of the energy storage element array 10 toward the Y-positive end (the other end), and the second holding portion 420 extends from the other end in the Y-axis direction of the energy storage element array 10 toward the Y-axis end. The third holding portion 430 connects the first holding portion 410 and the second holding portion 420 in the X-axis direction.

[0042] In this embodiment, the wiring unit 400 further includes a busbar holder 480 that holds a plurality of busbars 380. The busbar holder 480 and the wire holding member 401 are spaced apart from each other and connected by a plurality of connecting parts 490 (not shown in Figures 1 and 2). The connecting parts 490 are also called, for example, "stem," "arm," or "support part," and are extended from one of the busbar holder 480 and the wire holding member 401 to the other, thereby connecting the spaced-apart busbar holder 480 and the wire holding member 401. As a result, one of the busbar holder 480 and the wire holding member 401 can support the other.

[0043] Examples of materials used to form the wiring unit 400 include insulating materials such as PC, PP, PE, PS, or PPS, which are also used to form the spacer 200. Details of the wiring unit 400 and its surrounding configuration will be described later with reference to Figures 5 to 7.

[0044] [2. Explanation of energy storage elements] Next, the configuration of the energy storage element 100 will be explained using Figure 4. Figure 4 is a perspective view showing the configuration of the energy storage element 100 according to an embodiment. As shown in Figure 4, the energy storage element 100 has a container 110 and a pair of terminals 140 (positive and negative electrodes). Inside the container 110 are an electrode body, a pair of current collectors (positive and negative electrodes), and an electrolyte (non-aqueous electrolyte). A gasket is placed between the terminals 140 and the current collectors and the container 110, but these are not shown in the illustration. As for the electrolyte, there are no particular restrictions on its type as long as it does not impair the performance of the energy storage element 100, and various types can be selected. The gasket may be made of any material as long as it has insulating properties. In addition to the above components, the energy storage element 100 may also have a spacer placed to the side of the electrode body, an insulating film that encloses the electrode body, etc., and an insulating film (shrink tubing, etc.) that covers the outer surface of the container 110.

[0045] In this embodiment, when distinguishing between a pair of terminals 140 aligned in the X-axis direction, the terminal 140 in the negative X-axis direction is referred to as the first terminal 141, and the terminal 140 in the positive X-axis direction is referred to as the second terminal 142. Furthermore, when distinguishing between the polarity of the terminals 140, the negative terminal 140 is referred to as the negative terminal 140a, and the positive terminal 140 is referred to as the positive terminal 140b. That is, in the energy storage element 100 shown in Figure 4, the first terminal 141 is the negative terminal 140a, and the second terminal 142 is the positive terminal 140b. All of the multiple energy storage elements 100 in the energy storage element array 10 have the same configuration. However, multiple energy storage elements 100 are arranged such that some energy storage elements 100 have a first terminal 141 that is a negative terminal 140a (and a second terminal 142 that is a positive terminal 140b), and others have a first terminal 141 that is a positive terminal 140b (and a second terminal 142 that is a negative terminal 140a), alternating between each other (see Figures 2 and 3).

[0046] The container 110 is a rectangular parallelepiped (square or box-shaped) case having a container body 120 with an opening and a lid plate 130 that closes the opening of the container body 120. The container body 120 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 110, and has an opening in the positive Z-axis direction. The lid plate 130 is a rectangular plate-shaped member that is long in the X-axis direction and constitutes the lid of the container 110, and is positioned in the positive Z-axis direction of the container body 120. The lid plate 130 is provided with a gas discharge valve 131 that releases pressure when the pressure inside the container 110 rises excessively, and an injection section 132 for injecting electrolyte into the container 110. The injection section 132 includes an injection hole formed in the lid plate 130 and an injection plug that closes the injection hole. The injection plug is fixed to the lid plate 130, for example by welding, with the injection hole closed. The material of the container 110 (container body 120 and lid plate 130) is not particularly limited and can be made of weldable (joinable) metals such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0047] The container 110 is sealed inside by welding or other means to the container body 120 after the electrode body and other components are housed inside the container body 120. The container 110 has a pair of long sides 111 on both sides in the Y-axis direction, a pair of short sides 112 on both sides in the X-axis direction, and a bottom surface 113 in the negative Z-axis direction. The long sides 111 are rectangular planar sections and are positioned opposite adjacent spacers 200 in the Y-axis direction. The long sides 111 are adjacent to the short sides 112 and the bottom surface 113, and have a larger area than the short sides 112. The short sides 112 are rectangular planar sections and are positioned opposite the walls of the spacers 200 and the case 300 in the X-axis direction. The short sides 112 are adjacent to the long sides 111 and the bottom surface 113, and have a smaller area than the long sides 111. The bottom surface 113 is a rectangular planar section and is positioned opposite the bottom wall of the case 300 in the Z-axis direction. The bottom surface 113 is positioned adjacent to the long side surface 111 and the short side surface 112.

[0048] Terminal 140 is a terminal member (negative terminal 140a or positive terminal 140b) of the energy storage element 100, which is placed on the cover plate 130. Specifically, terminal 140 is positioned so as to protrude in the positive Z-axis direction from the upper surface (terminal placement surface) of the cover plate 130. Terminal 140 which is the negative terminal 140a and terminal 140 which is the positive terminal 140b are spaced apart in the X-axis direction, and a gas discharge valve 131 and a liquid injection section 132 are positioned between the negative terminal 140a and the positive terminal 140b. In this embodiment, the gas discharge valve 131 is positioned at the center of the negative terminal 140a and the positive terminal 140b in the X-axis direction, and a liquid injection section 132 is provided between the gas discharge valve 131 and the negative terminal 140a. Terminal 140 is electrically connected to the positive or negative electrode plate of the electrode body via a current collector. In other words, the terminal 140 is a metal component that guides the electricity stored in the electrode body to the external space of the energy storage element 100, and also introduces electricity into the internal space of the energy storage element 100 in order to store electricity in the electrode body. The terminal 140 is made of aluminum, aluminum alloy, copper, copper alloy, or the like.

[0049] The electrode body is an energy storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a current collector foil made of a metal such as aluminum or an aluminum alloy, with a positive electrode active material layer formed on it. The negative electrode plate is a current collector foil made of a metal such as copper or a copper alloy, with a negative electrode active material layer formed on it. As for the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it is capable of intercalating and releasing lithium ions. The separator can be a microporous sheet or nonwoven fabric made of resin. In this embodiment, the electrode body is formed by laminating electrode plates (positive electrode plate and negative electrode plate) in the Y-axis direction. The electrode body may take any form, such as a wound electrode body formed by winding electrode plates (positive electrode plate and negative electrode plate), a stacked electrode body formed by laminating a plurality of flat electrode plates, or a bellows-type electrode body in which the electrode plates are folded in a bellows shape.

[0050] The current collector is a conductive current collector (positive electrode current collector and negative electrode current collector) that is electrically and mechanically connected to the terminal 140 and the electrode body. The positive electrode current collector is made of aluminum or an aluminum alloy, similar to the current collector foil of the positive electrode plate of the electrode body, and the negative electrode current collector is made of copper or a copper alloy, similar to the current collector foil of the negative electrode plate of the electrode body.

[0051] [3. Configuration of the wiring unit and its surroundings] Next, the configuration of the wiring unit 400 and its surroundings will be explained using Figures 5 to 7 in addition to Figures 1 to 4 described above. Figure 5 is an exploded perspective view of the wiring unit 400 according to the embodiment. In Figure 5, the first and second covers (415, 425) of the wire holding member 401 are open, and the three wires 500 are separated from the wire holding member 401. In Figure 5, the busbar cover 485 of the busbar holder 480 is open, and the 25 busbars 380 are separated from the busbar holder 480. The white arrows in Figure 5 indicate the direction of rotation when closing covers such as the busbar cover 485. Figure 6 is a schematic plan view showing the configuration of the wiring unit 400 and its surroundings according to the embodiment. In Figure 6, the approximate arrangement range of the busbar holder 480 is shown by a dotted rectangle, and the first and second covers (415, 425) of the wire holding member 401 are not shown. Furthermore, in Figure 6, some of the energy storage elements 100 and some of the spacers 200 in the energy storage element array 10 are shown in a simplified manner, and the other energy storage elements 100 and other spacers 200 are omitted from the illustration. In Figure 6, the third thermistor 550c and the third wire 500c shown in Figure 5 are omitted from the illustration. These supplementary points regarding Figure 6 also apply to Figure 8, which will be described later. Figure 7 is a schematic cross-sectional view showing the configuration of the wiring unit 400 and its surroundings according to the embodiment. In Figure 7, a simplified cross-section of the energy storage device 1 in the XZ plane passing through line VII-VII in Figure 6 is shown. In Figure 7, the spacers 200 are represented by dotted areas to clearly indicate their arrangement range, and the gas discharge valve 131 located in the Y-axis positive direction of the spacers 200 is also represented by dotted areas to clearly indicate its arrangement range. In Figure 7, only one wire 500 held by the wire holding member 401 is shown.

[0052] As shown in Figures 5 to 7, the wire holding member 401 has a housing groove 403 that includes a continuous portion from the first end 10a (see Figure 6), which is the end of the energy storage element row 10 in the negative Y-axis direction, to the second end 10b (see Figure 6), which is the end of the energy storage element row 10 in the positive Y-axis direction. When one or more wires 500 are housed in the housing groove 403, the wire holding member 401 holds the one or more wires 500.

[0053] The wire holding member 401 has three parts that form the series of receiving grooves 403 described above. Specifically, the wire holding member 401 has a first holding part 410, a second holding part 420, and a third holding part 430. The first holding part 410 extends from the first end 10a to the second end 10b of the energy storage element row 10, and the second holding part 420 extends from the second end 10b to the first end 10a of the energy storage element row 10. The third holding part 430 is positioned to connect the first holding part 410 and the second holding part 420 in the X-axis direction. More specifically, the first holding part 410 is positioned from the first end 10a of the energy storage element row 10 to a spacer 200b located approximately in the center in the Y-axis direction. The second holding part 420 is positioned from the second end 10b of the energy storage element row 10 to a spacer 200b located approximately in the center in the Y-axis direction. Furthermore, multiple gas exhaust valves 131 are arranged in the Y-axis direction, and the third retaining portion 430 is positioned to intersect with the direction in which these multiple gas exhaust valves 131 are aligned. The Y-axis direction is an example of a first direction, the negative Y-axis direction is an example of one side of the first direction, and the positive Y-axis direction is an example of the other side of the first direction. The positive Z-axis direction is an example of a second direction that intersects with the first direction. The X-axis direction is an example of a third direction that intersects with both the first and second directions.

[0054] The first retaining portion 410 has a first main body portion 411 that forms a part of the housing groove 403 and a first cover 415 that covers the part of the housing groove 403 from the Z-axis positive direction. The second retaining portion 420 has a second main body portion 421 that forms a part of the housing groove 403 and a second cover 425 that covers the part of the housing groove 403 from the Z-axis positive direction. In this embodiment, the third retaining portion 430 is composed only of a part that forms a part of the housing groove 403, but it may also have a cover like the first retaining portion 410 and the second retaining portion 420.

[0055] As described above, the wire holding member 401, which is composed of three parts, is positioned in this embodiment between the busbar holders 480 located at both ends in the X-axis direction. To distinguish between these two busbar holders 480, as shown in Figure 6, the busbar holder 480 in the negative X-axis direction is referred to as busbar holder 480a, and the busbar holder 480 in the positive X-axis direction is referred to as busbar holder 480b.

[0056] The busbar holder 480 has a holder body 481 that holds a plurality of busbars 380 and a busbar cover 485 that covers the plurality of busbars 380. Specifically, the plurality of busbars 380 include four types of busbars 380 (busbars 380a to 380d). Busbar 380a is joined to the terminals 140 of two adjacent energy storage elements 100 separated by a spacer 200a (see Figure 3). Busbar 380b is joined to the terminals 140 of two adjacent energy storage elements 100 separated by a spacer 200b (see Figure 3) positioned in the center of the energy storage element row 10 in the Y-axis direction. In this embodiment, the two adjacent terminals 140 in the Y-axis direction are, for example, the negative terminal 140a and the positive terminal 140b, as shown in Figure 6. In other words, in this embodiment, multiple energy storage elements 100 are connected in series by multiple busbars 380a and one busbar 380b. A busbar 380c is connected to the negative terminal of the energy storage element array 10 having multiple energy storage elements 100 connected in series, and a busbar 380d is connected to the positive terminal of the energy storage element array 10.

[0057] Specifically, if the energy storage element array 10 is such that the energy storage element 100 located furthest in the negative Y-axis direction is designated as the first energy storage element 100A, and the energy storage element 100 located furthest in the positive Y-axis direction is designated as the second energy storage element 100B, then the arrangement of busbars 380c and 380d is described as follows. The first energy storage element 100A is located at the first end 10a of the energy storage element array 10, and the second energy storage element 100B is located at the second end 10b of the energy storage element array 10. Busbar 380c is connected to the negative terminal 140a (see Figure 6) of the first energy storage element 100A, which is the negative terminal of the energy storage element array 10. Busbar 380c is electrically connected to a negative external terminal (not shown) via a conductive member such as another busbar. Busbar 380d is connected to the positive terminal 140b (see Figure 6) of the second energy storage element 100B, which is the positive terminal of the energy storage element array 10. Busbar 380d is electrically connected to a positive external terminal (not shown) via a conductive member such as another busbar. There are no particular limitations on the electrical connection configuration of the multiple energy storage elements 100 included in the energy storage element array 10. As described above, all energy storage elements 100 may be connected in series, or multiple groups of energy storage elements 100, each containing two or more energy storage elements 100 connected in parallel, may be connected in series. All energy storage elements 100 may be connected in parallel.

[0058] As described above, the wire holding member 401, located between the busbar holders 480a and 480b that hold multiple busbars 380, holds a wire 500 to which a thermistor 550 for temperature detection is connected, as shown in Figures 5 and 6. In the energy storage device 1 according to this embodiment, thermistors 550 are placed at a total of three locations: both ends in the arrangement direction (Y-axis direction) of the energy storage element array 10, and one location between both ends, in order to detect the temperature of the energy storage element array 10 over a wide range. When distinguishing between these three thermistors 550, they are referred to as the first thermistor 550a, the second thermistor 550b, and the third thermistor 550c. The same applies when distinguishing between the wires 500 connected to each of these thermistors 550.

[0059] Specifically, as shown in Figure 6, a first thermistor 550a is placed on the first energy storage element 100A located at the first end 10a of the energy storage element array 10. A second thermistor 550b is placed on the second energy storage element 100B located at the second end 10b of the energy storage element array 10. Although not shown in Figure 6, a third thermistor 550c (see Figure 5) is placed on one of the energy storage elements 100 between the first energy storage element 100A and the second energy storage element 100B. The first wire 500a is connected to the first thermistor 550a, the second wire 500b is connected to the second thermistor 550b, and the third wire 500c is connected to the third thermistor 550c.

[0060] The thermistor 550 is positioned on the surface of the energy storage element 100 that is to be detected, facing the wire holding member 401, that is, on the outer surface of the cover plate 130. In order to accurately detect the temperature of the energy storage element 100, it is preferable that the thermistor 550 be positioned in close contact with the energy storage element 100. For this reason, the thermistor 550 is required to be positioned in contact with the flat portion of the cover plate 130 of the energy storage element 100. In this regard, the elongated cover plate 130 in the X-axis direction has a pair of terminals 140 located at both ends in the X-axis direction, a gas discharge valve 131 located in the center in the X-axis direction, and a liquid injection section 132 (see Figures 4 and 6). Specifically, as shown in Figure 4, the liquid injection section 132 is positioned between the gas discharge valve 131 and the negative electrode terminal 140a. The liquid injection section 132 is a part that forms irregularities on the upper surface (the surface in the positive Z-axis direction) of the cover plate 130. Therefore, it is preferable to place the thermistor 550 between the gas exhaust valve 131 and the positive terminal 140b (see Figure 4), where a relatively large flat surface is formed on the cover plate 130.

[0061] As a result, in the first energy storage element 100A, as shown in Figure 6, the first thermistor 550a is positioned between the first terminal 141, which is the positive terminal 140b, and the gas discharge valve 131. That is, when the energy storage element array 10 is viewed from the Z-axis positive direction, the first thermistor 550a is positioned in the first region 810, which is the region between the multiple first terminals 141 and the multiple gas discharge valves 131. In this embodiment, the multiple first terminals 141 are aligned in the Y-axis direction, and the multiple gas discharge valves 131 are aligned in the Y-axis direction. Therefore, when the energy storage element array 10 is viewed from the Z-axis positive direction, the first region 810 extends in the Y-axis direction between the row of multiple first terminals 141 (terminal row) and the row of multiple gas discharge valves 131 (discharge valve row).

[0062] In the energy storage element array 10 of this embodiment, energy storage elements 100 with their positive terminal 140b facing the negative X-axis direction and energy storage elements 100 with their negative terminal 140a facing the negative X-axis direction are arranged alternately. In other words, energy storage elements 100 with the first terminal 141 being the positive terminal 140b and energy storage elements 100 with the first terminal 141 being the negative terminal 140a are arranged alternately. Therefore, in the energy storage element array 10 having 24 energy storage elements 100, the second energy storage element 100B, which is the 24th energy storage element 100 when the first energy storage element 100A located at the first end 10a is considered the 1st, has the first terminal 141 as the negative terminal 140a. Consequently, when viewed from the positive Z-axis direction, the liquid injection section 132 exists in the portion of the second energy storage element 100B belonging to the first region 810 (the portion between the first terminal 141 and the gas discharge valve 131) (see Figure 6). As a result, the second thermistor 550b is positioned in the portion of the second energy storage element 100B that belongs to the second region 820. The second region 820 is the region opposite to the first region 810, with the multiple gas exhaust valves 131 in between, as shown in Figure 6. More specifically, the second thermistor 550b is positioned in the third region 821, which is part of the second region 820. The third region 821 is the region between the multiple second terminals 142 and the multiple gas exhaust valves 131.

[0063] Thus, the first thermistor 550a and the second thermistor 550b, which are positioned at both ends in the arrangement direction (Y-axis direction) of the energy storage element array 10, are located in regions (first region 810 and second region 820) on opposite sides of the multiple gas discharge valves 131 (discharge valve array). Therefore, the first wire 500a connected to the first thermistor 550a and the second wire 500b connected to the second thermistor 550b cannot be held by, for example, a single linear holding member extending in the Y-axis direction in the first region 810. Thus, a structure in which the first wire 500a and the second wire 500b are held together by a holding member with a wide width in the X-axis direction can also be considered. However, in this case, since the holding member is located opposite the multiple gas discharge valves 131 in the Z-axis direction, if gas is discharged from any of the gas discharge valves 131, the holding member will obstruct the discharge of that gas. Furthermore, it is conceivable to arrange two holding members, one for the first wire 500a and the other for the second wire 500b. However, in this case, the first wire 500a and the second wire 500b are drawn out from positions spaced apart in the X-axis direction at the first end 10a of the energy storage element array 10. Therefore, the connection work between the first wire 500a and the second wire 500b and electrical equipment such as control circuits may become complicated.

[0064] In relation to the above-mentioned problems, the wire holding member 401 according to this embodiment, as shown in Figures 5 and 6, has a first holding portion 410 located in the first region 810, a second holding portion 420 located in the second region 820, and a third holding portion 430 connecting the first holding portion 410 and the second holding portion 420. Furthermore, the third holding portion 430 is located in a position that does not face the plurality of gas discharge valves 131. Therefore, the wire holding member 401 is configured in a manner that does not easily obstruct the discharge of gas from each of the plurality of gas discharge valves 131, and that the first wire 500a and the second wire 500b can be pulled out together from the end in the Y-axis direction.

[0065] As described above, the energy storage device 1 according to this embodiment comprises an energy storage element array 10 having a plurality of energy storage elements 100 arranged in line in the Y-axis direction, and a wire holding member 401 that holds one or more wires 500. The wire holding member 401 is arranged opposite to the energy storage element array 10 in the Z-axis positive direction intersecting the Y-axis direction. Each of the plurality of energy storage elements 100 has a first terminal 141 and a gas discharge valve 131 arranged in the Z-axis positive direction. The wire holding member 401 has a first holding portion 410, a second holding portion 420, and a third holding portion 430. The first holding portion 410 extends from a first end 10a, which is one end of the energy storage element array 10 in the Y-axis direction, toward a second end 10b, which is the other end in the Y-axis direction. The second holding portion 420 extends from the second end 10b toward the first end 10a of the energy storage element array 10. The third retaining portion 430 connects the first retaining portion 410 and the second retaining portion 420 in the X-axis direction, which intersects the Y-axis direction and the Z-axis plus direction. When viewed from the Z-axis plus direction, the first retaining portion 410 is located in the first region 810 between the multiple gas discharge valves 131 and the multiple first terminals 141. When viewed from the Z-axis plus direction, the second retaining portion 420 is located in the second region 820, on the opposite side of the first region 810, with the multiple gas discharge valves 131 in between. When viewed from the Z-axis plus direction, the third retaining portion 430 is positioned so as not to overlap with the multiple gas discharge valves 131.

[0066] Thus, in the energy storage device 1 according to this embodiment, when viewed from the Z-axis positive direction, the first holding portion 410 of the wire holding member 401 is located in the first region 810, and the second holding portion 420 of the wire holding member 401 is located in the second region 820, opposite to the first region 810, with a plurality of gas discharge valves 131 arranged in the Y-axis direction in between. Therefore, information (e.g., temperature) of the second end 10b or its vicinity in the energy storage element array 10 in the second region 820 can be obtained from the first end 10a of the energy storage element array 10 in the first region 810 via one or more wires 500 held by the wire holding member 401. Furthermore, the first holding portion 410, the second holding portion 420, and the third holding portion 430 of the wire holding member 401 are all located in positions that do not overlap with any of the plurality of gas discharge valves 131 when viewed from the Z-axis positive direction. Therefore, when gas is discharged from any of the multiple gas discharge valves 131, the wire holding member 401 and one or more wires 500 are unlikely to obstruct the discharge of gas. Thus, the energy storage device 1 according to this embodiment is an energy storage device that can arrange the wires 500 using space efficiently.

[0067] More specifically, in the energy storage device 1 according to this embodiment, a first thermistor 550a is positioned in the first region 810 when viewed from the positive Z-axis direction, on the first energy storage element 100A located at the first end 10a of the energy storage element row 10, among the plurality of energy storage elements 100. A second thermistor 550b is positioned in the second region 820 when viewed from the positive Z-axis direction, on the second energy storage element 100B located at the second end 10b of the energy storage element row 10, among the plurality of energy storage elements 100. One or more electric wires 500 include a first electric wire 500a electrically connected to the first thermistor 550a and a second electric wire 500b electrically connected to the second thermistor 550b.

[0068] Thus, even if the first thermistor 550a and the second thermistor 550b are positioned at different locations in the X-axis direction, the first wire 500a and the second wire 500b can be drawn together from one end of the energy storage element array 10 in the Y-axis direction. Furthermore, in this embodiment, the first wire 500a and the second wire 500b can be drawn together from a position shifted in the negative X-axis direction from the positions of the multiple gas discharge valves 131 in the energy storage element array 10. Therefore, even if the first thermistor 550a and the second thermistor 550b have to be positioned at different locations in the X-axis direction due to the number of energy storage elements 100 in the energy storage element array 10 or the electrical connection configuration (selection and application of parallel and series connections), the first wire 500a and the second wire 500b can be efficiently arranged.

[0069] In this embodiment, a through-hole is provided in the wall portion of the wire holding member 401 facing the energy storage element row 10, and the thermistor 550 is fixed to the wire holding member 401 with the thermistor 550 inserted into the through-hole. The thermistor 550 fixed to the wire holding member 401 is pressed against the cover plate 130 of the energy storage element 100 located opposite the thermistor 550. This positions the thermistor 550 relative to the energy storage element 100. The arrangement of the thermistor 550 is not limited to the above embodiment; for example, the thermistor 550 may be positioned relative to the energy storage element 100 using a separate component from the wire holding member 401.

[0070] In the energy storage device 1 according to this embodiment, the energy storage element array 10 includes a spacer 200b positioned between two adjacent energy storage elements 100, as shown in Figures 2 and 3, and the third holding portion 430 is positioned to overlap with the spacer 200b when viewed from the Z-axis positive direction, as shown in Figure 6.

[0071] In this configuration, the third retaining portion 430 is positioned using the space above the spacer 200b, which is used for the protection or to improve the positional stability of at least one energy storage element 100. This is advantageous in terms of efficiently using the space to position the electric wires 500. The position of the third retaining portion 430 is not limited to this. The third retaining portion 430 may be positioned so as to overlap with the spacer 200a, which is positioned between two adjacent energy storage elements 100, when viewed from the Z-axis positive direction. "When viewed from the Z-axis positive direction, the third retaining portion 430 and the spacer 200 overlap" does not mean that the entire third retaining portion 430 overlaps with the spacer 200. When viewed from the Z-axis positive direction, the third retaining portion 430 and the gas discharge valve 131 of the energy storage element 100 adjacent to the spacer 200 do not overlap, so a part of the third retaining portion 430 may protrude from the spacer 200.

[0072] The energy storage device 1 according to this embodiment further includes a busbar 380 connected to the first terminals 141 of two or more of the multiple energy storage elements 100, and a busbar holder 480 that holds the busbar 380. The wire holding member 401 is a member that forms a housing groove 403 in which one or more wires 500 are housed, and is arranged spaced apart from the busbar holder 480 (see Figures 2, 5, and 6).

[0073] With this configuration, the position, size, or shape of the wire holding member 401 can be set to a position, size, or shape suitable for the wiring layout of the electric wire 500, regardless of the position, size, or shape of the busbar holder 480.

[0074] In this embodiment, as shown in Figure 6, the busbar holder 480 and the wire holding member 401 are connected by a plurality of connection parts 490 that extend from one to the other. The wiring unit 400 configured in this way can be manufactured as a single component (a single part) that integrates the busbar holder 480, the wire holding member 401, and the plurality of connection parts 490 by integral molding using the aforementioned resin material such as PC or PP as the raw material. Therefore, for example, the wiring unit 400 can be manufactured more easily than when the busbar holder 480, the wire holding member 401, and the plurality of connection parts 490 are each manufactured as separate components and then assembled. In other words, it is not essential that the wiring unit 400 integrates the busbar holder 480, the wire holding member 401, and the plurality of connection parts 490. However, it is preferable for the wiring unit 400 to integrate these three types of components (parts) from the viewpoint of improving the manufacturing efficiency of the energy storage device 1 or reducing the number of parts.

[0075] Furthermore, in this embodiment, the space between the wire holding member 401 and the busbar holder 480, formed by the separation of the wire holding member 401 and the busbar holder 480, is used as the arrangement space for the protrusions 250 of the multiple spacers 200. Specifically, as shown in Figure 7, the space between the wire holding member 401 and the busbar holder 480 is arranged in the space between the spacer body 210 and the Z-axis positive direction for the protrusions 250. More specifically, the spacer 200 has a pair of protrusions 250 that are spaced apart in the X-axis direction. In the wiring unit 400, spaces (gaps) are formed between the busbar holders 480a and 480b on both sides of the wire holding member 401 in the X-axis direction. The pair of protrusions 250 are arranged in the spaces (gaps) on both sides of the wire holding member 401 in the X-axis direction.

[0076] The pair of protrusions 250 arranged in this manner are connected in the Y-axis direction as described above (see Figure 2), thereby forming wall portions 250A and 250B that are spaced apart in the X-axis direction. In this embodiment, the lid 320 located in the Z-axis positive direction of the wall portions 250A and 250B is provided with contact portions 325 that contact each of the wall portions 250A and 250B, as shown in Figure 7. The contact portions 325 of the lid 320 do not need to be a portion that protrudes from the lower surface of the lid 320 (the surface facing the Z-axis negative direction), as shown in Figure 7. A part of the lower surface of the lid 320 may be the contact portion 325 that contacts each of the wall portions 250A and 250B. The contact portion 325 may be a separate member from the lid 320. In other words, a contact portion 325 made of a separate member from the lid 320 may be placed between each of the wall portions 250A and 250B and the lid 320.

[0077] In the energy storage device 1 according to this embodiment, the first holding portion 410 has an opening 402 through which the ends of one or more electric wires 500 protrude, and the opening 402 is located at the end of the first holding portion 410 in the negative Y-axis direction, as shown in Figure 6.

[0078] With this configuration, one or more electric wires 500 are pulled out from the opening 402 to the outside of the electric wire holding member 401. Therefore, even if the number of electric wires 500 increases, they can be easily handled as a single bundle of electric wires 500.

[0079] In the energy storage device 1 according to this embodiment, the third holding portion 430 connects the Y-axis positive end of the first holding portion 410 and the Y-axis negative end of the second holding portion 420. Specifically, as shown in Figure 6, the first holding end 419, which is the Y-axis positive end of the first holding portion 410, is located between the Y-axis ends (first end 10a and second end 10b) of the energy storage element array 10. The second holding end 429, which is the Y-axis negative end of the second holding portion 420, is located between the Y-axis ends (first end 10a and second end 10b) of the energy storage element array 10. The third holding portion 430 connects the first holding end 419 and the second holding end 429.

[0080] With this configuration, the lengths of the first holding part 410 and the second holding part 420 in the Y-axis direction can be set so as not to cover the entire Y-axis direction of the energy storage element array 10. Therefore, when viewed from the Z-axis positive direction, a relatively large amount of space (gap) can be secured for visual inspection or image processing of the energy storage element array 10. Furthermore, the combined length of the first holding part 410, the second holding part 420, and the third holding part 430 can cover the entire Y-axis direction of the energy storage element array 10. Therefore, there is a high degree of freedom regarding the placement of the thermistor 550 in the energy storage element array 10 (selection of the energy storage element 100 on which the thermistor 550 is placed). In this embodiment, thermistors 550 (third thermistor 550c) are placed not only on the energy storage elements 100 at both ends in the Y-axis direction of the energy storage element array 10 (first energy storage element 100A and second energy storage element 100B), but also on one of the energy storage elements 100 between the two ends (see Figure 5). Therefore, the temperature distribution of the energy storage element array 10 can be measured or estimated with greater accuracy. Since the wire holding member 401 is formed to cover the entire Y-axis direction of the energy storage element array 10, thermistors 550 may be placed on each of any two or more energy storage elements 100 between the energy storage elements 100 at both ends.

[0081] The above description focuses on the wiring unit 400 and its surrounding components of the energy storage device 1 according to the embodiment. However, the wiring unit 400 and its surrounding components may have configurations different from those shown in Figures 1 to 7. Therefore, the following describes some modifications of the wiring unit 400 and its surrounding components, focusing on the differences from the above embodiment.

[0082] [4. Explanation of the modified example] Figure 8 is a schematic plan view showing the configuration of a wiring unit 400 and its surroundings according to a modified embodiment. The wiring unit 400 shown in Figure 8 includes a wire holding member 401a. The wire holding member 401a has a first holding portion 410, a second holding portion 420, and a third holding portion 430. The first holding portion 410 extends from the first end 10a to the second end 10b of the energy storage element array 10. The second holding portion 420 extends from the second end 10b to the first end 10a of the energy storage element array 10. The third holding portion 430 connects the first holding portion 410 and the second holding portion 420 in the X-axis direction. When viewed from the Z-axis positive direction, the first holding portion 410 is located in the first region 810 between a plurality of gas discharge valves 131 and a plurality of first terminals 141. The second holding portion 420 is located in the second region 820, opposite to the first region 810, with the multiple gas discharge valves 131 in between, when viewed from the Z-axis positive direction. The third holding portion 430 is positioned so as not to overlap with the multiple gas discharge valves 131 when viewed from the Z-axis positive direction. In these configurations, the wire holding member 401a according to this modified example is common to the wire holding member 401 according to the embodiment (see Figure 6).

[0083] In this modified example, the position of the third holding portion 430 differs from that of the embodiment. Specifically, in this modified example, the energy storage element array 10 includes a spacer 200c located at one end or the other end in the Y-axis direction, and the third holding portion 430 is positioned to overlap with the spacer 200c when viewed from the Z-axis positive direction. More specifically, in this modified example, the third holding portion 430 is positioned in the Z-axis positive direction of the spacer 200c located at the Y-axis positive end (second end 10b), which is the other end in the Y-axis direction. In this modified example, as in the previously described embodiment, a plurality of gas exhaust valves 131 are arranged in the Y-axis direction, and the third holding portion 430 is positioned to intersect with the direction in which these plurality of gas exhaust valves 131 are arranged. Furthermore, in this modified example, the third holding portion 430 is positioned in the XY plane to bypass the Z-axis projection range of the plurality of gas exhaust valves 131 so as not to overlap with the plurality of gas exhaust valves 131 in the Z-axis direction.

[0084] Even in this case, the first holding portion 410, the second holding portion 420, and the third holding portion 430 of the wire holding member 401a are all positioned so as not to overlap with any of the multiple gas discharge valves 131 when viewed from the Z-axis positive direction. Therefore, the wire holding member 401a and one or more wires 500 are unlikely to obstruct gas discharge. Furthermore, the third holding portion 430 is positioned using the space above the spacer 200c, which is used to protect the energy storage elements 100 at the Y-axis end of the energy storage element array 10 or to improve their positional stability. This is advantageous from the viewpoint of efficiently using space to position the wires 500.

[0085] [5. Explanation of other variations] Although embodiments and modifications thereof of the present invention have been described above, the present invention is not limited to the above embodiments and modifications. The embodiments and modifications disclosed herein are illustrative in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0086] The wiring unit 400 does not need to include a busbar holder 480. The wiring unit 400 only needs to include at least a wire holding member 401. In other words, the busbar holder 480 and the wire holding member 401 may be separate components. If the busbar holder 480 and the wire holding member 401 are separate components, the wiring unit 400 can be placed in the energy storage element array 10 after the busbar holder 480 has been placed in the energy storage element array 10 and the multiple busbars 380 have been joined to the multiple terminals 140 by welding or other means. This suppresses, for example, contamination or damage to the wire holding member 401 due to spatter during welding of the busbars 380 and terminals 140.

[0087] The wire 500 held by the wire holding member 401 does not have to be connected to the thermistor 550. For example, the wire 500, which is a voltage detection line connected to one of the multiple busbars 380, may be held by the wire holding member 401.

[0088] The energy storage element array 10 may include restraining members (end plates and side plates) that restrain a plurality of energy storage elements 100 and spacers 200. If the energy storage element array 10 includes restraining members, the end plates positioned at both ends of the energy storage element array 10 in the Y-axis direction may be spacers positioned at one end or the other end of the energy storage element array 10 in the Y-axis direction. In other words, the third holding portion 430 shown in Figure 8 may be positioned in the Z-axis positive direction of an end plate, which is a type of spacer.

[0089] It is not essential that three thermistors 550 (see Figure 5) are placed in the energy storage element array 10. In the energy storage element array 10, a thermistor 550 (second thermistor 550b) may be placed only on the second energy storage element 100B. Even in this case, if it is desired to lead the second wire 500b out from the first region 810 at the first end 10a of the energy storage element array 10, the wire holding member 401, which is positioned so as not to face any of the gas discharge valves 131, is useful.

[0090] The multiple spacers 200 provided in the energy storage element array 10 do not necessarily have to have the function of holding at least one energy storage element 100. Each of the multiple spacers 200 may be simply a flat plate-shaped member.

[0091] The present invention also includes forms constructed by arbitrarily combining the components of the above embodiments and their variations. [Industrial applicability]

[0092] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of symbols]

[0093] 1. Energy storage device 10 Energy storage element array 10a First end 10b Second end 100 energy storage elements 100A First Energy Storage Element 100B Second Energy Storage Element 130 Lid plate 131 Gas discharge valve 132 Injection section 140 terminals 140a negative terminal 140b Positive terminal 141 First terminal 142 Second terminal 200, 200a, 200b, 200c spacers 380, 380a, 380b, 380c, 380d busbars 400 Wiring Unit 401, 401a Wire holding member 402 Opening 403 Storage groove 410 First holding part 419 First holding end 420 Second holding part 429 Second holding end 430 Third holding part 480, 480a, 480b busbar holder 490 Connection part 500 wire 500a Daiichi Electric Cable 500b second electric wire 500c third wire 550 Thermistor 550a First Thermistor 550b Second Thermistor 550c Third Thermistor 810 First area 820 Second area 821 Third Realm

Claims

1. A series of energy storage elements having multiple energy storage elements arranged in a line in the first direction, A wire holding member for holding one or more wires, comprising a wire holding member arranged opposite to the array of energy storage elements in a second direction intersecting the first direction, Each of the plurality of energy storage elements has a terminal and a gas discharge valve arranged in the second direction, The wire holding member is, A first holding portion extending from one end, which is one end in the first direction of the energy storage element array, toward the other end, which is the other end in the first direction. A second holding portion extending from the other end toward the one end of the aforementioned energy storage element array, The first retaining portion and the second retaining portion are connected by a third retaining portion in a third direction intersecting the first direction and the second direction, The first holding portion, when viewed from the second direction, is located in the first region between the plurality of gas discharge valves and the plurality of terminals. The second retaining portion, when viewed from the second direction, is located in the second region opposite to the first region, with the plurality of gas discharge valves in between. The third retaining portion is positioned such that, when viewed from the second direction, it does not overlap with the plurality of gas discharge valves. Energy storage device.

2. Of the plurality of energy storage elements, the first energy storage element located at one end of the array of energy storage elements has a first thermistor positioned in a location included in the first region when viewed from the second direction. Of the plurality of energy storage elements, the second energy storage element located at the other end of the array of energy storage elements has a second thermistor positioned in a location included in the second region when viewed from the second direction. The one or more wires mentioned above include a first wire electrically connected to the first thermistor and a second wire electrically connected to the second thermistor. The energy storage device according to claim 1.

3. The array of energy storage elements includes a spacer placed between two adjacent energy storage elements among the plurality of energy storage elements. The third retaining portion is positioned so as to overlap with the spacer when viewed from the second direction. The energy storage device according to claim 1 or 2.

4. The array of energy storage elements includes a spacer disposed at one end or the other end in the first direction. The third retaining portion is positioned so as to overlap with the spacer when viewed from the second direction. The energy storage device according to claim 1 or 2.

5. Furthermore, a busbar is connected to the terminals of two or more of the plurality of energy storage elements, The busbar holder for holding the busbar is provided, The wire holding member is a member that forms a groove for accommodating one or more wires, and is positioned spaced apart from the busbar holder. The energy storage device according to claim 1 or 2.

6. The first holding portion has an opening through which the ends of one or more electric wires protrude, and is located at one end of the first holding portion in the first direction and has an opening. The energy storage device according to claim 1 or 2.

7. The third retaining portion connects the other end of the first retaining portion in the first direction with the one end of the second retaining portion in the first direction. The energy storage device according to claim 1 or 2.

Images