Energy storage device

Abstract

To provide a power storage device having a structure which can prevent an increase in the number of components.SOLUTION: A power storage device 1 comprises: a power storage element 100 having an electrode terminal 120; an outer package 10 which houses the power storage element 100; and an insulation member 30. The power storage element 100 is disposed in a posture with the electrode terminal 120 oriented in the positive direction of a Z-axis. The insulation member 30 is disposed on a lateral side, of the power storage element 100, in the positive direction of the Z-axis. A portion of the insulation member 30 is provided with a holding part 32 for holding a fastening member 66. The outer package 10 has a supporting part 16 for supporting the holding part 32.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an electricity storage device including an electricity storage element.

Background Art

[0002] Patent Document 1 discloses an assembled battery including a battery module having a plurality of battery cells (electricity storage elements), an auxiliary module, and an upper case. The auxiliary module has an auxiliary pedestal, and the battery module has a cell holder. With the auxiliary pedestal placed on the cell holder, the cell holder and the auxiliary pedestal are screw-coupled by inserting a fastening bolt from the upper surface side and screwing it into a screw hole of the cell holder. Accordingly, the auxiliary module is fixed onto the battery module.

Prior Art Literature

Patent Literature

[0003]

Patent Literature 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the above-mentioned conventional assembled battery (electricity storage device), a screw hole is provided in a cell holder provided in the battery module, and a structure in which the auxiliary pedestal and the cell holder are fastened using the screw hole and a bolt is employed. However, members such as the cell holder included in the electricity storage device are members (insulating members) formed of an electrically insulating material such as resin, and the insulating member has lower mechanical strength than metal members such as bolts. Therefore, in a structure where a bolt is screwed into a part of the insulating member, problems such as deformation or displacement of the part are likely to occur. To solve this problem, for example, it is conceivable to prepare a separate member for reinforcing the part, but in this case, the problem of an increase in the number of parts arises.

[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 having a structure that can suppress an increase in the number of parts. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present invention is an energy storage element having electrode terminals, comprising: an energy storage element arranged in a position with the electrode terminals facing a first direction; an outer casing housing the energy storage element; and an insulating member arranged on the side of the energy storage element in the first direction, wherein a part of the insulating member is provided with a holding portion for holding a fastening member, and the outer casing has a support portion for supporting the holding portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an energy storage device having a structure that can suppress an increase in the number of parts. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the external appearance of the energy storage device according to the embodiment. [Figure 2] This is an exploded perspective view of the energy storage device according to the embodiment. [Figure 3] This is an exploded perspective view of the energy storage element unit according to the embodiment. [Figure 4] This is a perspective view showing the configuration of the retaining portion and its surrounding area of ​​the insulating member according to the embodiment. [Figure 5] This is an exploded perspective view corresponding to Figure 4. [Modes for carrying out the invention]

[0009] An energy storage device according to one aspect of the present invention is an energy storage element having electrode terminals, comprising: an energy storage element arranged in a position with the electrode terminals facing a first direction; an outer casing housing the energy storage element; and an insulating member arranged on the side of the energy storage element in the first direction, wherein a part of the insulating member is provided with a holding portion for holding a fastening member, and the outer casing has a support portion for supporting the holding portion.

[0010] In this configuration, fastening members used to connect multiple components are held by a retaining portion of an insulating member, and the retaining portion is supported by a support portion of the outer casing. In other words, since the fastening member, such as a bolt or nut, is held by the retaining portion which is part of the insulating member, the movement or rotation of the fastening member is suppressed. Furthermore, since the retaining portion is supported by the support portion of the outer casing, the effectiveness of the suppression function against the movement or rotation of the fastening member by the retaining portion is ensured. In other words, the retaining portion is supported by a part of the outer casing without the need for a separate member to suppress the displacement or deformation of the retaining portion. Thus, the energy storage device according to this embodiment has a structure that can suppress an increase in the number of parts.

[0011] The insulating member may have an insulating body portion that holds a busbar electrically connected to the electrode terminals of the energy storage element, and a holding portion that protrudes from the insulating body portion when viewed from the first direction, and the busbar and other conductive members are fastened together by the fastening member held by the holding portion.

[0012] In this configuration, the fastening member is held using a portion of the insulating member that serves as the busbar holder, and the fastening member is held in a position that protrudes from the insulating main body when viewed from the first direction (plan view). This suppresses the increase in the height of the energy storage device (when the first direction is upward) due to the arrangement of the holding portion and the fastening member. Even if the outer casing is made of metal, since the holding portion is part of the insulating member, the problem of conductivity between the fastening member, which is held by the holding portion and electrically connected to the busbar, and the metal outer casing is unlikely to occur. In other words, the holding portion functions as an insulating member that electrically insulates the fastening member from the outer casing.

[0013] The holding portion may be such that, when viewed from the first direction, it holds the fastening member, which has a non-circular outer shape, by sandwiching it from both sides.

[0014] With this configuration, the retaining part can restrict the rotation of a bolt head or nut, for example, if its external shape is polygonal when viewed from the axial direction, from rotating in the circumferential direction. In other words, it functions as an anti-rotation device for the bolt head or nut. Since the retaining part is supported by the support part, it is also possible to firmly fasten the bolt or nut connected to the fastening member to the fastening member.

[0015] The outer casing may further have a facing wall portion that faces the energy storage element in a second direction perpendicular to the first direction, and the support portion may include a rib provided on the facing wall portion, which is positioned in contact with the holding portion.

[0016] In this configuration, for example, ribs are provided on the opposing wall portion that restricts the movement of the energy storage element inside the outer casing, and the movement of the holding portion is restricted when these ribs come into contact with the holding portion. In other words, a part of the member that plays the role of restricting the movement of the energy storage element (the opposing wall portion) can be used as at least a part of the support portion. This is advantageous in suppressing an increase in the number of parts.

[0017] The following description of an energy storage device according to an embodiment (including its modifications) of the present invention will be given with reference to the drawings. The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are examples and are not intended to limit the present invention. Dimensions and other specifications are not strictly illustrated in each figure. Furthermore, the same or similar components are denoted by the same reference numerals in each figure.

[0018] In the following description and drawings, the opposing direction of the short side surfaces of the electricity storage element, or the longitudinal direction of the lid plate of the container of the electricity storage element, is defined as the Y-axis direction. The arranging direction of a plurality of electricity storage elements, or the opposing direction of the long side surfaces of the electricity storage element, is defined as the X-axis direction. The arranging direction of the main body of the exterior body (exterior body main body) and the lid body of the electricity storage device, or the vertical direction, is defined as the Z-axis direction. These X-axis direction, Y-axis direction and Z-axis direction are directions that intersect each other (orthogonally intersect in the present embodiment). Depending on the usage mode, the Z-axis direction may not be the vertical direction, but for convenience of description, the following description will be made with the Z-axis direction as the vertical direction.

[0019] In the following description, for example, the positive X-axis direction refers to the arrow direction of the X-axis, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. When simply referred to as "X-axis direction", it means both directions parallel to the X-axis or either one of the directions. The same applies to the terms relating to the Y-axis and the Z-axis.

[0020] Furthermore, expressions indicating relative directions or postures, such as parallel and orthogonal, also include cases where the direction or posture is not strictly such. For example, the statement that two directions are orthogonal does not only mean that the two directions are completely orthogonal, but also means that they are substantially orthogonal, that is, include a difference of, for example, about several percent. In the following description, when the term "insulation" is used, it means "electrical insulation".

[0021] (Embodiment) [1. General Description of Electricity Storage Device] First, a schematic configuration of the electricity storage device 1 according to the embodiment will be described. FIG. 1 is a perspective view showing the external appearance of the electricity storage device 1 according to the embodiment. FIG. 2 is an exploded perspective view of the electricity storage device 1 according to the embodiment. FIG. 3 is an exploded perspective view of the electricity storage element unit 20 according to the embodiment. In addition to the members shown in FIG. 2 and subsequent drawings, other members such as sensors for temperature and voltage measurement and electric wires connected to the sensors are also housed inside the exterior body 10, but illustration and description of these members are omitted.

[0022] 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, for example, a battery module (battery pack) used for power storage or power supply purposes. Specifically, 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.

[0023] As shown in Figures 1 and 2, the energy storage device 1 comprises an outer casing 10 and an energy storage element unit 20 housed within the outer casing 10. An insulating member 30 is positioned above the energy storage element unit 20. In this embodiment, the insulating member 30 is a busbar holder that holds the busbar 60 connected to the energy storage element 100.

[0024] The outer casing 10 is a box-shaped container (module case) that constitutes the housing of the energy storage device 1. In other words, the outer casing 10 is positioned outside the energy storage element unit 20 and the insulating member 30, fixing them in place and protecting them from impacts, etc. In this embodiment, the outer casing 10 is made of a metal such as iron, aluminum, or an aluminum alloy. In addition to metal, resins can also be used as the material for forming the outer casing 10. Examples of such resins include polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), or ABS resin.

[0025] The outer casing 10 has an opening 12a at its Z-axis positive end into which the energy storage element unit 20 can be inserted, and a bottom wall portion 19 located opposite the opening 12a. Specifically, the outer casing 10 comprises an outer casing body 12 and a lid 11, with the opening 12a and the bottom wall portion 19 provided on the outer casing body 12. The outer casing body 12 is a bottomed rectangular cylindrical housing with the opening 12a formed therein, and it houses the energy storage element unit 20. The outer casing body 12 has an opposing wall portion 15 that faces the energy storage element unit 20 in the Y-axis direction. The opposing wall portion 15 restricts the movement of the energy storage element unit 20 in the Y-axis negative direction and also serves to separate the inside from the outside of the outer casing 10.

[0026] The cover 11 is a rectangular member that closes the opening 12a of the outer casing body 12. The cover 11 is joined to the outer casing body 12 by a plurality of bolts 41, thereby fixing the cover 11 to the outer casing body 12. Specifically, through holes 43 are provided in the peripheral edge of the cover 11 through which the bolts 41 pass, and fixing holes 42 are provided in the opening peripheral edge 12b, which is the peripheral edge of the opening 12a of the outer casing body 12. The bolts 41 are screwed into the fixing holes 42 of the outer casing body 12 while passing through the through holes 43 of the cover 11. This joins the cover 11 to the opening peripheral edge 12b of the outer casing body 12.

[0027] The energy storage element unit 20 has a plurality of energy storage elements 100 and a cell holder 130 that holds each of the plurality of energy storage elements 100. The energy storage element 100 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. As shown in Figure 3, the energy storage element 100 has a flat rectangular parallelepiped (square) shaped container 110 and a pair of electrode terminals 120 (positive and negative electrodes) fixed to the container 110. Inside the container 110 are an electrode body, current collector, electrolyte, etc. (not shown). An example of an electrode body of the energy storage element 100 is a wound-type electrode body formed by winding together layers arranged with a separator sandwiched between a positive electrode plate and a negative electrode plate. In addition, the energy storage element 100 may be equipped with a stacked electrode body formed by stacking multiple flat electrode plates, or a bellows-type electrode body formed by folding electrode plates in a bellows-like manner.

[0028] The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, but may be a secondary battery other than a non-aqueous electrolyte secondary battery, or a capacitor. The energy storage element 100 may not be a secondary battery, but a primary battery that allows the user to use the stored electricity without charging. 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. Furthermore, the shape of the energy storage element 100 is not limited to the above-mentioned prismatic shape, but may be other shapes such as polygonal prisms, cylindrical shapes, elliptical prisms, or oblong cylindrical shapes.

[0029] In this embodiment, as shown in Figure 3, the container 110 has a container body 111 and a lid plate 112 that closes the opening of the container body 111. The container 110 is structured so that after the electrode body or the like is placed inside the container body 111, the container body 111 and the lid plate 112 are joined by welding or the like to seal the inside. The material of the container 110 (container body 111 and lid plate 112) is not particularly limited and can be made of weldable (joinable) metals such as stainless steel, aluminum, aluminum alloy, iron, plated steel sheet, etc., but resin can also be used.

[0030] The container body 111 has a pair of long sides 110a and a pair of short sides 110b. Positive and negative electrode terminals 120 and a gas discharge valve 105 are arranged on the lid plate 112. The gas discharge valve 105 is a part that opens (opens) when the internal pressure of the container 110 rises excessively, thereby discharging the gas inside the container 110 to the outside. In the energy storage element unit 20, each of the multiple energy storage elements 100 is arranged in a position where the two electrode terminals 120 and the gas discharge valve 105 are oriented in the Z-axis positive direction, and the long sides 110a are oriented in the alignment direction (X-axis direction). In this embodiment, the Z-axis positive direction is an example of a first direction, and the Y-axis direction is an example of a second direction perpendicular to the first direction.

[0031] The energy storage element unit 20 has 12 energy storage elements 100 configured as described above. In this embodiment, each of the 12 energy storage elements 100 is positioned between two cell holders 130. In other words, the energy storage element unit 20 according to this embodiment has 13 cell holders 130. Of these cell holders 130, a pair of cell holders 130 located at both ends in the X-axis direction are referred to as cell holder 131 to distinguish them from the others. Of these cell holders 130, a cell holder 130 located between two adjacent energy storage elements 100 is referred to as cell holder 132 to distinguish it from the others.

[0032] The cell holder 130 has the function of stabilizing the position of the energy storage element 100 by holding it, as well as the function of insulating the container 110 of the energy storage element 100 from other conductive members adjacent to the energy storage element 100 (including the containers 110 of other energy storage elements 100). The cell holder 130 is formed from one of the electrically insulating resin materials that can be used as the material for the outer casing 10.

[0033] The insulating member 30 is a member positioned to the side of the energy storage element 100 in the first direction (positive Z-axis direction), and in this embodiment, it is a busbar holder that holds a plurality of busbars 60. The insulating member 30 is formed of, for example, one of the electrically insulating resin materials that can be used as the material for the exterior body 10.

[0034] In this embodiment, the insulating member 30 has an insulating body portion 31 having multiple busbar openings 31a for holding multiple busbars 60, and a holding portion 32 for holding a fastening member 66 into which a connecting bolt 65 (described later) is screwed. The busbars 60 arranged on the insulating body portion 31 of the insulating member 30 are positioned relative to the electrode terminals 120 to be joined, and in that state, are joined to the electrode terminals 120, for example, by laser welding. In this embodiment, in the 12 energy storage elements 100 of the energy storage element unit 20, three consecutively arranged energy storage elements 100 are connected in parallel by one busbar 60. This forms four sets of parallel-connected energy storage elements 100. Furthermore, the four sets of energy storage elements 100 are connected in series by three busbars 60.

[0035] In other words, the electrode terminals 120 of the two end sets of energy storage elements 100 in the four sets of energy storage elements 100 connected in series are the positive electrode (total positive terminal) and negative electrode (total negative terminal) of the energy storage element unit 20. In this embodiment, the positive electrode terminals 120 of one set (3 elements) of energy storage elements 100 at the X-axis negative end of the 12 energy storage elements 100 are the positive electrode (total positive terminal) of the energy storage element unit 20. The positive electrode terminals 120 of these three energy storage elements 100 are connected to busbar 60a (see Figure 2) among the multiple busbars 60. The negative electrode terminals 120 of one set (3 elements) of energy storage elements 100 at the X-axis positive end of the 12 energy storage elements 100 are the negative electrode (total negative terminal) of the energy storage element unit 20. The negative electrode terminals 120 of these three energy storage elements 100 are connected to busbar 60b (see Figure 2) among the multiple busbars 60.

[0036] The busbars 60a and 60b, respectively, which are connected to the positive and negative electrodes of the energy storage element unit 20, are connected to other conductive members by connecting bolts 65. Although not shown in the figure, the opposing wall portion 15 of the casing 10 is provided with openings through which the ends of the busbars 60a and 60b pass. The ends of the busbars 60a and 60b are exposed to the outside of the casing 10 through the openings provided in the opposing wall portion 15 (see Figure 1), and function as the positive and negative external terminals of the energy storage device 1.

[0037] In this embodiment, the connecting bolt 65 is screwed into a fastening member 66 held by a holding portion 32 formed by a part of the insulating member 30, thereby mechanically and electrically connecting the busbar 60 to other conductive members. In this embodiment, the fastening member 66 is a nut having a threaded hole sized to correspond to the connecting bolt 65. The insulating member 30 has two holding portions 32, of which the holding portion 32 that holds the fastening member 66 into which the connecting bolt 65 that passes through the busbar 60a is screwed will be referred to as holding portion 32A. Of the two holding portions 32, the holding portion 32 that holds the fastening member 66 into which the connecting bolt 65 that passes through the busbar 60b is screwed will be referred to as holding portion 32B. These two holding portions 32 are supported by a support portion 16 of the outer casing 10.

[0038] Inside the outer casing 10, a control device and electrical equipment such as relays for controlling the charging state of the multiple energy storage elements 100 of the energy storage element unit 20 may be arranged. In this case, the energy storage device 1 may include, for example, a positive external terminal and a negative external terminal fixed to the lid 11, each of which is electrically connected to the energy storage element unit 20 via electrical equipment and a busbar 60a or 60b.

[0039] The electrical connection configuration of the 12 energy storage elements 100 by the busbar 60 is not limited to the configuration described above. For example, all 12 energy storage elements 100 may be connected in series by multiple busbars 60. Furthermore, the number of energy storage elements 100 provided in the energy storage element unit 20 is not limited to 12. The number of energy storage elements 100 provided in the energy storage element unit 20 can be one or more.

[0040] In the energy storage device 1 configured in this way, the outer casing 10 has a support portion 16 that supports the holding portion 32, which is part of the insulating member 30. This suppresses displacement or deformation of the holding portion 32 when a connecting bolt 65 is screwed into the fastening member 66 held by the holding portion 32. The structure of the holding portion 32 and its surroundings will be described below with reference to Figures 4 and 5.

[0041] [2. Regarding the structure of the retaining part and its surroundings] Figure 4 is a perspective view showing the configuration of the retaining portion 32 and its surroundings in the insulating member 30 according to the embodiment. In Figure 4, the energy storage element unit 20 and the insulating member 30 are shown housed in the outer casing body 12. In Figures 4 and 5, the cover 11 is omitted from the illustration in order to clearly show the configuration of the retaining portion 32 and its surroundings. Figure 5 is an exploded perspective view corresponding to Figure 4. In Figure 5, the insulating member 30 is shown separated from the energy storage element unit 20, the busbar 60a is shown separated from the insulating member 30, and the fastening member 66 is shown separated from the retaining portion 32.

[0042] As shown in Figures 4 and 5, in this embodiment, the energy storage element unit 20 has a plurality of energy storage elements 100, and each of the plurality of energy storage elements 100 is arranged with its electrode terminals 120 facing in the Z-axis positive direction. An insulating member 30 is arranged on the side of the energy storage element unit 20 in the Z-axis positive direction, that is, at a position facing the electrode terminals 120 of the plurality of energy storage elements 100. The insulating body portion 31 of the insulating member 30 is a rectangular portion that is large enough to cover the energy storage element unit 20 when viewed from the Z-axis positive direction (plan view). The two holding portions 32 of the insulating member 30 are provided protruding from the insulating body portion 31 in a plan view. In this embodiment, the configuration and function of the two holding portions 32 (32A and 32B) are the same, so below, the explanation will mainly focus on the holding portion 32A on which the busbar 60a is arranged, and the explanation of the holding portion 32B will be omitted.

[0043] As shown in Figure 5, the holding portion 32A in this embodiment has a shape that extends along the busbar 60a protruding outward from the insulating main body 31, and also serves to insulate the busbar 60a from the member below it (part of the outer casing 10). A connecting bolt 65, which penetrates the busbar 60a and a conductive member 68, which is an example of another conductive member, is screwed into the fastening member 66 held by the holding portion 32A. In this way, the conductive member 68 and the busbar 60a are mechanically and electrically connected. The conductive member 68 is a busbar or a terminal at the end of an electric wire, etc. The busbar 60a and, for example, an external device to which the energy storage device 1 supplies power are electrically connected via the conductive member 68. Although not shown in Figure 5, a conductive member such as a busbar can also be connected to the end of the busbar 60b that is exposed from the outer casing 10 by the connecting bolt 65 and fastening member 66.

[0044] The retaining portion 32A has a recess 33 (see Figure 5) for accommodating the fastening member 66. The recess 33 holds the fastening member 66, which has a non-circular outer shape in a plan view, by sandwiching it from both sides. As a result, the movement of the fastening member 66 is restricted at least in a direction perpendicular to the Z-axis, and rotation around the Z-axis is also restricted. In this embodiment, a metal nut with a hexagonal outer shape in a plan view is used as the fastening member 66, which has a non-circular outer shape in a plan view.

[0045] Thus, the retaining portion 32A has the basic functions of restricting the movement and preventing rotation of the fastening member 66. However, the retaining portion 32A is part of the insulating member 30 and, like the insulating main body 31, is made of resin material. Therefore, it is difficult for the retaining portion 32A to completely resist the external force applied when connecting (screwing in) the connecting bolt 65 and the fastening member 66, and as a result, the retaining portion 32A may be displaced or deformed by such external force. To solve this problem, for example, it is conceivable to place a separate metal member (reinforcement member) on the outer surface of the retaining portion 32A, but in this case, other problems such as an increase in the number of parts of the energy storage device 1 will arise.

[0046] Therefore, in the energy storage device 1 according to this embodiment, a structure is adopted in which a part of the outer casing 10 that houses the energy storage element unit 20 is used to support the holding portion 32A. Specifically, as shown in Figures 4 and 5, the outer casing 10 has a support portion 16 that supports the holding portion 32A. The support portion 16 is in contact with the holding portion 32A or is positioned near the holding portion 32A. When the holding portion 32A is about to be displaced or deformed, the support portion 16 can provide a reaction force to the holding portion 32A in a direction that suppresses such displacement or deformation.

[0047] As described above, the energy storage device 1 according to this embodiment comprises an energy storage element 100 having electrode terminals 120, an outer casing 10 housing the energy storage element 100, and an insulating member 30. The energy storage element 100 is positioned with the electrode terminals 120 facing in the positive Z-axis direction. The insulating member 30 is positioned to the side of the energy storage element 100 in the positive Z-axis direction. A retaining portion 32 for holding a fastening member 66 is provided on a part of the insulating member 30, and the outer casing 10 has a support portion 16 for supporting the retaining portion 32.

[0048] As described above, in this embodiment, the fastening member 66 used to connect multiple members is held by a holding portion 32 of the insulating member 30, and the holding portion 32 is supported by a support portion 16 of the outer casing 10. In other words, since the fastening member 66 (nut in this embodiment) is held by the holding portion 32, which is part of the insulating member 30, the movement or rotation of the fastening member 66 is suppressed. Furthermore, since the holding portion 32 is supported by the support portion 16 of the outer casing 10, the effectiveness of the suppression function of the holding portion 32 against the movement or rotation of the fastening member 66 is ensured. In other words, the holding portion 32 is supported by a part of the outer casing 10 without the use of a separate member to suppress the displacement or deformation of the holding portion 32. Thus, the energy storage device 1 according to this embodiment is an energy storage device having a structure that can suppress an increase in the number of parts.

[0049] In this embodiment, the insulating member 30 has an insulating main body portion 31 that holds the busbar 60 electrically connected to the electrode terminals 120 of the energy storage element 100, and a holding portion 32 that protrudes from the insulating main body portion 31 when viewed from the Z-axis positive direction. The busbar 60 is fastened to another conductive member (conductive member 68) by a fastening member 66 held by the holding portion 32.

[0050] Thus, in this embodiment, as shown in Figures 4 and 5, the fastening member 66 is held using a part of the insulating member 30, which is a busbar holder, and the fastening member 66 is held in a position that protrudes from the insulating main body 31 in a plan view. This suppresses the increase in the height of the energy storage device 1 (when the Z-axis positive direction is upward) due to the arrangement of the holding part 32 and the fastening member 66. Furthermore, even when the outer casing 10 is made of metal as in this embodiment, since the holding part 32 is part of the insulating member 30, the problem of conductivity between the fastening member 66, which is held by the holding part 32 and electrically connected to the busbar 60, and the metal outer casing 10 is unlikely to occur. In other words, the holding part 32 functions as an insulating member 30 that electrically insulates the fastening member 66 and the outer casing 10.

[0051] In this embodiment, the holding portion 32 holds the fastening member 66, which has a non-circular outer shape, by sandwiching it from both sides in a plan view.

[0052] With this configuration, the retaining portion 32 can restrict the fastening member 66, which has a polygonal outer shape when viewed from the axial direction, from rotating in the circumferential direction. In this embodiment, the fastening member 66 is a nut with a hexagonal outer shape, and the retaining portion 32 functions as a rotation stopper for the nut. Since the retaining portion 32 is supported by the support portion 16, it is also possible to firmly tighten the connecting bolt 65 to the fastening member 66.

[0053] In this embodiment, the support portion 16 that achieves the above effect is provided on the opposing wall portion 15 of the outer casing 10. Specifically, the outer casing 10 has an opposing wall portion 15 that faces the energy storage element 100 in the Y-axis direction perpendicular to the Z-axis positive direction. The support portion 16 is a rib 16a provided on the opposing wall portion 15, and includes a rib 16a that is positioned in contact with the holding portion 32.

[0054] In this configuration, a rib 16a is provided on the opposing wall portion 15, and the movement of the holding portion 32 is restricted by the rib 16a contacting the holding portion 32. In other words, a part of the member (opposing wall portion 15) that serves to restrict the movement of the energy storage element 100, or to separate the inside and outside of the outer casing 10, can be used as at least a part of the support portion 16. This is advantageous in suppressing an increase in the number of parts. More specifically, in this embodiment, as shown in Figure 5, the support portion 16 has a pair of ribs 16a. The pair of ribs 16a are positioned to sandwich the portion of the holding portion 32 where the fastening member 66 is located, in a direction perpendicular to the Z-axis direction. Therefore, the support portion 16 can act to suppress the displacement or deformation of the holding portion 32 in response to external forces from various directions applied to the holding portion 32.

[0055] The position, size, and shape of the pair of ribs 16a do not have to be those shown in Figure 4. For example, the pair of ribs 16a may be provided on the inner surface of the opposing wall portion 15. The pair of ribs 16a may also have different sizes and shapes from each other.

[0056] If the rib 16a of the support portion 16 is provided on the inner surface of the opposing wall portion 15, the rib 16a may be connected to the bottom wall portion 19.

[0057] As a result, the ribs 16a are positioned on the outer casing 10 in a way that makes them less likely to tip over. In other words, the bottom wall portion 19 of the outer casing 10 can be used to construct a support portion 16 with high mechanical strength. Therefore, even if the external force acting on the fastening member 66 is relatively large, the ribs 16a of the support portion 16 can resist that external force and suppress the movement or deformation of the holding portion 32.

[0058] [3. Variant] Although an embodiment of the present invention, the energy storage device 1, has been described above, the present invention is not limited to this embodiment. In other words, the embodiments disclosed herein are illustrative and not restrictive in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0059] For example, the fastening member 66 does not have to be a nut. For example, a bolt may be used as the fastening member 66. In this case, for example, the bolt may be held in the holding part 32 in a position where the shaft of the bolt protrudes from the holding part 32 in the Z-axis positive direction. In this case, for example, the bus bar 60a and the conductive member 68 (see Figure 5) can be electrically and mechanically connected by passing the shaft of the bolt through the bus bar 60a and the conductive member 68 and then tightening the shaft with a nut. During this connection work, rotational torque is generated in the bolt, but since the bolt is held in the holding part 32 and the holding part 32 is supported by the support part 16, displacement or deformation of the holding part 32 is suppressed.

[0060] The fastening member 66 does not need to be used for connecting conductive members to each other, such as connecting the busbar 60 and the conductive member 68. For example, the fastening member 66 may be used simply for the purpose of fixing (mechanically connecting) one of two members to the other. Even in this case, the holding portion 32 that holds the fastening member 66 is supported by the support portion 16, which is part of the exterior body 10, so that one of the two members can be firmly fastened to the other.

[0061] In the above embodiment, the support portion 16 is provided on the metal exterior body 10 as an integral part of the exterior body 10 when the metal exterior body 10 is manufactured by casting and / or machining. However, the support portion 16 may be manufactured as a separate component from the exterior body 10 and then fixed to a part of the exterior body 10 (such as a wall) by welding or the like.

[0062] The insulating member 30 positioned on the side of the energy storage element 100 in the Z-axis positive direction does not need to be a busbar holder. For example, an inner lid positioned inside the outer casing 10 to cover the energy storage element unit 20, or an electrical component tray positioned on the side of the energy storage element unit 20 in the Z-axis positive direction, may be used as the insulating member 30 having a holding portion 32. The insulating member 30 does not need to be entirely made of an insulating material such as resin. For example, a member in which the surface of a metal base material is covered with an insulating material such as resin may be used as the insulating member 30.

[0063] The support portion 16 does not need to be composed of a pair of ribs 16a as shown in Figure 5. The support portion 16 only needs to be able to suppress displacement or deformation of the retaining portion 32 by contacting at least a part of the retaining portion 32 when the retaining portion 32 attempts to be displaced or deformed, and there are no particular limitations on its shape and size. The portion where the support portion 16 is located does not need to be the opposing wall portion 15 of the outer casing 10. The position and shape of the support portion 16 may be appropriately determined according to the position of the retaining portion 32 inside the outer casing 10.

[0064] The exterior body 10 having the support portion 16 does not have to be the outermost housing of the energy storage device 1. For example, a case that covers at least a part of the energy storage element unit 20, which is located inside the outermost housing of the energy storage device 1, may be used as the exterior body 10. A case having one or more openings for heat dissipation, etc., in the wall portion that separates the inside and outside of the exterior body 10 may also be used as the exterior body 10. It is not essential that the exterior body 10 has a portion that can be clearly recognized as a "wall portion". The exterior body 10 may also be a frame structure member made up of multiple frames combined together.

[0065] It is not essential that the outer casing 10 be made of a metal such as iron or aluminum; as mentioned above, the outer casing 10 may be formed from a resin such as PC, PP, or PE. However, from the viewpoint of obtaining a high effect in suppressing the displacement or deformation of the holding part 32 by the support part 16, which is part of the outer casing 10, it is preferable that the outer casing 10 be made of metal.

[0066] The energy storage element unit 20 does not necessarily have to have multiple cell holders 130. For example, instead of multiple cell holders 130, flat, insulating spacers may be arranged along the long sides 110a of each of the multiple energy storage elements 100. If an insulating material such as an insulating film is placed on the outer surface of each container 110 of the multiple energy storage elements 100, then cell holders and spacers or other materials do not need to be placed between adjacent energy storage elements 100.

[0067] The energy storage element unit 20 may include not only multiple energy storage elements 100 and multiple cell holders 130, but also multiple busbars 60 and insulating members 30 (see Figure 2) joined to the electrode terminals 120 of the multiple energy storage elements 100. In other words, a configuration in which insulating members 30 and multiple busbars 60 are added to the energy storage element unit 20 according to the embodiment can also be called an "energy storage element unit".

[0068] The present invention also includes forms constructed by arbitrarily combining the components included in the above embodiments and their modified examples. [Industrial applicability]

[0069] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of Symbols]

[0070] 1. Energy storage device 10 Exterior 15 Opposing wall section 16 Support part 16a Rib 19 Bottom wall section 30 Insulating material 31 Insulating body 32, 32A, 32B holding part 33 Recess 60, 60a, 60b busbars 65 connecting bolts 66 Fastening members 68 Conductive material 100 energy storage elements 120 electrode terminals

Claims

1. A power storage element having electrode terminals, wherein the electrode terminals are positioned in a orientation facing a first direction, An outer casing housing the aforementioned energy storage element, The energy storage element comprises an insulating member disposed on the side in the first direction, A portion of the insulating member is provided with a holding portion for holding the fastening member. The exterior body has a support portion that supports the holding portion, The insulating member has an insulating body portion that holds a busbar electrically connected to the electrode terminals of the energy storage element, and a holding portion that protrudes from the insulating body portion when viewed from the first direction. The busbar and other conductive members are fastened together by the fastening member held by the holding portion. The support portion, the holding portion, the busbar, and the other conductive members are arranged in this order in the first direction. Energy storage device.

2. A power storage element having electrode terminals, wherein the electrode terminals are positioned in a orientation facing a first direction, An outer casing housing the aforementioned energy storage element, The energy storage element comprises an insulating member disposed on the side in the first direction, A portion of the insulating member is provided with a holding portion for holding the fastening member. The exterior body has a support portion that supports the holding portion without contacting the fastening member. Energy storage device.

3. A power storage element having electrode terminals, wherein the electrode terminals are positioned in a orientation facing a first direction, An outer casing housing the aforementioned energy storage element, The energy storage element comprises an insulating member disposed on the side in the first direction, A portion of the insulating member is provided with a holding portion for holding the fastening member. The exterior body has a support portion that supports the holding portion, The outer casing further has a facing wall portion that faces the energy storage element in a second direction perpendicular to the first direction, The support portion is a rib that is elongated in the first direction and provided on the opposing wall portion, and includes a rib that is positioned in contact with the holding portion. Energy storage device.

4. A power storage element having electrode terminals, wherein the electrode terminals are positioned in a orientation facing a first direction, An outer casing housing the aforementioned energy storage element, The energy storage element comprises an insulating member disposed on the side in the first direction, A portion of the insulating member is provided with a holding portion for holding the fastening member. The exterior body has a support portion that supports the holding portion, The outer casing further has a facing wall portion that faces the energy storage element in a second direction perpendicular to the first direction, The support portion includes a pair of ribs provided on the opposing wall portion, which sandwich the portion of the holding portion where the fastening member is arranged in a direction perpendicular to the first direction. Energy storage device.

5. The insulating member has an insulating body portion that holds a busbar electrically connected to the electrode terminals of the energy storage element, and a holding portion that protrudes from the insulating body portion when viewed from the first direction. The busbar and other conductive members are fastened together by the fastening member held by the holding portion. The energy storage device according to any one of claims 2 to 4.

6. The holding portion, when viewed from the first direction, holds the fastening member, which has a non-circular outer shape, by sandwiching it from both sides. The energy storage device according to any one of claims 1 to 5.

7. The outer casing further has a facing wall portion that faces the energy storage element in a second direction perpendicular to the first direction, The support portion is a rib provided on the opposing wall portion, and includes a rib positioned in contact with the holding portion. The energy storage device according to claim 1 or 2.

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