Energy storage device

Abstract

To provide a power storage device capable of improving the operability of an assembling operation of a side plate to a power storage element.SOLUTION: A power storage device 10 comprises an insulation member 600 arranged between a power storage element 100 and a side plate 500. The side plate 500 includes: a plate main body part 510 that is opposite to the power storage element 100 in a first direction; and a plate projection part 530 that is projected in the first direction from the plate main body part 510, and is opposite to the power storage element 100 in a second direction. The insulation member 600 includes: an insulation main body part 610 that is arranged between the power storage element 100 and the plate main body part 510; and an insulation projection part 630 that is projected in the first direction from the insulation main body part 610, and is arranged between the power storage element 100 and the plate projection part 530 in the second direction. The insulation projection part 630 includes a groove part 631 that is convex in a direction separated from the power storage element 100 in the second direction, and is extended in a third direction.SELECTED DRAWING: Figure 5

Description

[[Technical Field]]

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

[0002] Conventionally, there has been known an electricity storage device including an electricity storage element, a side plate arranged laterally of the electricity storage element, and an insulating member arranged between the electricity storage element and the side plate. For example, Patent Document 1 discloses a battery module (electricity storage device) in which a side separator (insulating member) is arranged between a battery (electricity storage element) and a restraining member (side plate). [[Related Art]] [[Patent Literature]]

[0003] [[Patent Document 1]] International Publication No. WO 2020 / 166182 [[Summary of the Invention]] [[Problems to be Solved by the Invention]]

[0004] In the above-described conventional electricity storage device, there are cases where the side plate has a protrusion that protrudes toward the electricity storage element and faces the electricity storage element in the vertical direction (hereinafter referred to as a plate protrusion). In this case, the insulating member has a protrusion that protrudes between the electricity storage element and the plate protrusion (hereinafter referred to as an insulating protrusion) to insulate between the electricity storage element and the plate protrusion. In the above-mentioned Patent Document 1, the restraining member (side plate) has an arm portion (plate protrusion) that protrudes toward the battery (electricity storage element) and faces the battery in the vertical direction, and the side separator (insulating member) has a second portion and a third portion (insulating protrusion) between the battery and the arm portion. In such a configuration, when assembling the side plate to the electricity storage element, if the insulating protrusion bends (warps) toward the electricity storage element side, the insulating protrusion becomes an obstacle, which may make the assembling work difficult.

[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 can improve the workability of assembling side plates to energy storage elements. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present invention comprises an energy storage element, a side plate disposed to the side of the energy storage element in a first direction, and an insulating member disposed between the energy storage element and the side plate, wherein the side plate has a plate body portion facing the energy storage element in the first direction, and a plate projection portion protruding from the plate body portion in the first direction and facing the energy storage element in a second direction intersecting the first direction, and the insulating member has an insulating body portion disposed between the energy storage element and the plate body portion, and an insulating projection portion protruding from the insulating body portion in the first direction and disposed between the energy storage element and the plate projection portion in the second direction, wherein the insulating projection portion is recessed in a direction away from the energy storage element in the second direction and has a groove portion extending in a third direction intersecting the first and second directions.

[0007] The present invention can be realized not only as such an energy storage device, but also as a combination of a side plate and an insulating member, or as an insulating member itself. [Effects of the Invention]

[0008] The energy storage device according to the present invention makes it possible to improve the workability of assembling the side plate to the energy storage element. [Brief explanation of the drawing]

[0009] [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 showing the components of the energy storage device according to the embodiment when it is disassembled. [Figure 3]This is a perspective view showing the configuration of the energy storage element according to the embodiment. [Figure 4] This is a perspective view showing the configuration of the insulating member according to the embodiment. [Figure 5] This is a cross-sectional view showing an insulating member according to the embodiment attached to a side plate. [Figure 6A] This is a cross-sectional view showing the configuration of the insulating protrusion of the insulating member according to a modified example 1 of the embodiment. [Figure 6B] This is a cross-sectional view showing the configuration of the insulating protrusion of the insulating member according to a modified example 1 of the embodiment. [Figure 7] This is a cross-sectional view showing the configuration of the bent portion of the insulating member according to a modified example 2 of the embodiment. [Modes for carrying out the invention]

[0010] An energy storage device according to one aspect of the present invention comprises an energy storage element, a side plate disposed to the side of the energy storage element in a first direction, and an insulating member disposed between the energy storage element and the side plate, wherein the side plate has a plate body portion facing the energy storage element in the first direction, and a plate projection portion protruding from the plate body portion in the first direction and facing the energy storage element in a second direction intersecting the first direction, and the insulating member has an insulating body portion disposed between the energy storage element and the plate body portion, and an insulating projection portion protruding from the insulating body portion in the first direction and disposed between the energy storage element and the plate projection portion in the second direction, wherein the insulating projection portion is recessed in a direction away from the energy storage element in the second direction and has a groove portion extending in a third direction intersecting the first and second directions.

[0011] According to this, in the energy storage device, the insulating protrusion of the insulating member, which is positioned between the energy storage element and the plate protrusion of the side plate, has a groove that is recessed in the direction away from the energy storage element and extends in a third direction. In this way, having a groove that is recessed in the direction away from the energy storage element prevents the insulating protrusion from bending (warping) toward the energy storage element. As a result, the insulating protrusion does not get in the way when assembling the side plate to the energy storage element, thereby improving the workability of the assembly work of the side plate to the energy storage element.

[0012] The insulating body portion may be positioned opposite the central portion of the energy storage element in the second direction.

[0013] According to this, in an insulating member, by positioning the insulating body, which is placed between the energy storage element and the plate body, at a position facing the center of the energy storage element, the insulation between the energy storage element and the side plate (plate body) can be improved.

[0014] The insulating projection may have a first thin-walled portion that extends in the third direction at a position overlapping with the groove when viewed from the second direction, and is thinner than the adjacent portion.

[0015] According to this, in the insulating member, the first thin-walled portion is formed at a position overlapping with the groove of the insulating protrusion, which further suppresses the bending (warping) of the insulating protrusion toward the energy storage element. This further improves the workability of assembling the side plate to the energy storage element.

[0016] The first thin-walled portion may be formed to be thinner than the portion adjacent to it by forming a cut in the surface of the groove that faces the energy storage element.

[0017] According to this arrangement, in the insulating member, the first thin-walled portion can be easily formed by forming a notch in the groove of the insulating protrusion. Further, by forming a notch on a surface of the groove portion facing the power storage element to form the first thin-walled portion, bending (warping) of the insulating protrusion toward the power storage element side is further suppressed. This makes it possible to further improve the workability of assembling the side plate to the power storage element.

[0018] The insulating protrusion may have, on a surface opposite to the groove portion, a protrusion protruding in a direction away from the power storage element in the second direction and extending in the third direction, and the protrusion may be disposed at a position farther from the insulating main body than the plate protrusion in the first direction.

[0019] In the insulating member, the groove portion is formed by curving the insulating protrusion, so that a protrusion is formed on the opposite side of the groove portion. Therefore, with a configuration in which the protrusion is formed on the surface of the insulating protrusion opposite to the groove portion, the groove portion can be easily formed. By disposing the protrusion at a position farther from the insulating main body than the plate protrusion of the side plate, it is possible to suppress an increase in size in the second direction caused by the protrusion overlapping the plate protrusion in the second direction. If the protrusion is disposed so as to abut against the plate protrusion in the first direction, the insulating protrusion can be positioned relative to the plate protrusion in the first direction, and movement of the insulating protrusion in the first direction can be suppressed.

[0020] The insulating member may have a second thin-walled portion extending in the third direction and having a smaller thickness than adjacent portions at a boundary between the insulating main body and the insulating protrusion.

[0021] According to this arrangement, by forming the second thin-walled portion at the boundary (bent portion) between the insulating main body and the insulating protrusion of the insulating member, it is possible to suppress the insulating protrusion from bending (warping) toward the power storage element side relative to the insulating main body even at the boundary. This makes it possible to further improve the workability of assembling the side plate to the power storage element.

[0022] 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 only and are not intended to limit the present invention. Dimensions in each figure are not precisely illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0023] In the following description and drawings, the direction in which a pair of electrode terminals are aligned in one energy storage element, the direction in which a pair of short sides of a container for one energy storage element are aligned, the direction in which a pair of side plates are aligned, or the direction in which a pair of insulating members are aligned is defined as the X-axis direction. The direction in which multiple energy storage elements are aligned, the direction in which multiple spacers are aligned, the direction in which a pair of end plates are aligned, the direction in which an energy storage element, spacer, and end plate are aligned, the direction in which a pair of long sides of a container for one energy storage element are aligned, or the thickness direction of an energy storage element, spacer, or end plate is defined as the Y-axis direction. The direction in which the container body and lid of an energy storage element container are aligned, or the vertical direction is defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect each other (orthogonal in this embodiment). Note that 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.

[0024] In the following explanation, for example, 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 referred to as the X-axis direction, it refers to either the X-axis positive direction or the X-axis negative direction, or either direction. The same applies to the Y-axis and Z-axis directions. In the following, the X-axis direction may also be referred to as the first direction, the Z-axis direction as the second direction, and the Y-axis direction as the third 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 parallel, it means not only that the two directions are perfectly parallel, but also that they are substantially parallel, i.e., that they include a difference of, for example, a few percent. Furthermore, in the following explanation, when the term "insulation" is used, it means "electrical insulation."

[0025] (Embodiment) [1. General description of the energy storage device 10] First, a general description of the energy storage device 10 in this embodiment will be given. Figure 1 is a perspective view showing the external appearance of the energy storage device 10 according to this embodiment. Figure 2 is an exploded perspective view showing the individual components when the energy storage device 10 according to this embodiment is disassembled.

[0026] The energy storage device 10 is a device that can charge electricity from an external source and discharge electricity to the outside, and in this embodiment, it has a substantially rectangular parallelepiped shape. For example, the energy storage device 10 is a battery module (battery pack) used for power storage or power supply purposes. Specifically, the energy storage device 10 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, linear motor cars, and hybrid trains equipped with both diesel engines and electric motors. The energy storage device 10 can also be used as a stationary battery for household or commercial use.

[0027] As shown in Figures 1 and 2, the energy storage device 10 comprises a plurality of energy storage elements 100, a plurality of spacers 200, a pair of end plates 400, a pair of side plates 500, and a pair of insulating members 600. The energy storage device 10 also includes busbars for connecting the energy storage elements 100 in series or parallel, but these are not shown or described. In addition to the above components, the energy storage device 10 may also include a busbar frame for positioning the busbars, an exterior housing for the above components, external terminals connected to external busbars, etc., and electrical equipment such as circuit boards, fuses, relays, and connectors for monitoring or controlling the charging and discharging states of the energy storage elements 100.

[0028] 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), and in this embodiment, eight energy storage elements 100 are arranged in the Y-axis direction. The size, shape, and number of energy storage elements 100 arranged are not limited, and for example, only one energy storage element 100 may be arranged. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and 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 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. A detailed explanation of the configuration of the energy storage element 100 will be given later.

[0029] The spacer 200 is a plate-shaped member positioned adjacent to the energy storage element 100 and insulating the energy storage element 100 from other members. The spacer 200 is positioned in the positive or negative Y-axis direction of the energy storage element 100 and insulates between two adjacent energy storage elements 100, and between the end energy storage elements 100 and the end plate 400. The spacer 200 is also positioned to cover the short side (short side 112 described later), both ends of the X-axis direction of the bottom surface (bottom surface 113 described later), and both ends of the X-axis direction of the top surface (cover 130 described later). In this embodiment, nine spacers 200 are positioned corresponding to eight energy storage elements 100, but the position and number of spacers 200 are not particularly limited. The spacer 200 is formed from an insulating material 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 an insulating coated metal, or from a heat insulating material such as damper material.

[0030] The end plate 400 and side plate 500 are restraining members that compress (restrain) the energy storage elements 100 from the outside in the direction of alignment of the multiple energy storage elements 100 (Y-axis direction). In other words, the end plate 400 and side plate 500 compress (restrain) each energy storage element 100 included in the multiple energy storage elements 100 from both sides in the direction of alignment by sandwiching the multiple energy storage elements 100 from both sides in the direction of alignment. The end plate 400 and side plate 500 are made of metal members such as steel or stainless steel from the viewpoint of ensuring strength, but the material is not particularly limited, and for example, they may be made of a highly insulating material, or a metal material may be treated with an insulating coating.

[0031] The end plates 400 are plate-shaped (flat block-shaped) restraining members that are positioned on both sides in the Y-axis direction of the multiple energy storage elements 100 and the multiple spacers 200, and hold the multiple energy storage elements 100 etc. by sandwiching them from both sides in the direction of their alignment (Y-axis direction). A pair of end plates 400 are positioned to sandwich the multiple energy storage elements 100 and the multiple spacers 200 in the Y-axis direction (the stacking direction of the electrode plates of the electrode bodies of the energy storage elements 100), and restrain them.

[0032] The side plate 500 is a plate-shaped, elongated restraining member positioned to the side of the multiple energy storage elements 100 and the multiple spacers 200 in the X-axis direction (first direction). Specifically, the side plate 500 is positioned to the side of the insulating member 600 so as to sandwich the insulating member 600 between the multiple energy storage elements 100 and the multiple spacers 200 in the X-axis direction. Both ends of the side plate 500 are attached to a pair of end plates 400, and by connecting the pair of end plates 400, the side plate 500 restrains the multiple energy storage elements 100 and the multiple spacers 200. The side plate 500 extends in the Y-axis direction so as to straddle the multiple energy storage elements 100 and the multiple spacers 200, and applies a restraining force to the multiple energy storage elements 100, etc. in the direction of their alignment (Y-axis direction).

[0033] In this embodiment, a pair of side plates 500 are arranged on both sides in the X-axis direction of a plurality of energy storage elements 100 and a plurality of spacers 200. Each of the pair of side plates 500 is attached to the X-axis ends of a pair of end plates 400 at both ends in the Y-axis direction. As a result, the pair of side plates 500, together with the pair of end plates 400, sandwich and restrain the plurality of energy storage elements 100, etc., from both sides in the X-axis direction and both sides in the Y-axis direction. Specifically, the side plates 500 are connected (joined) to the end plates 400 by a plurality of (three in this embodiment) connecting members 500a arranged in the Z-axis direction. In this embodiment, the connecting members 500a are bolts (screws) and are fastened by screwing into the female threaded portion formed on the end plate 400. The connection (joining) of the side plates 500 to the end plates 400 is not limited to fixing with bolts (screws), and may be joined by welding or adhesive, etc.

[0034] The side plate 500 has a plate body portion 510 and a pair of plate protrusions 520 and 530 (see Figures 2 and 5, etc.). The plate body portion 510 is the part that is positioned opposite the energy storage element 100 in the X-axis direction (first direction). Specifically, the plate body portion 510 is a flat, rectangular part that is positioned opposite the insulating body portion 610 of the insulating member 600 (described later) in the X-axis direction and extends in the Y-axis direction, parallel to the YZ plane. In other words, the plate body portion 510 is positioned in the X-axis direction, sandwiching the insulating body portion 610 between the multiple energy storage elements 100 and the multiple spacers 200. The plate body portion 510 is positioned in contact with the insulating body portion 610 in the X-axis direction.

[0035] The pair of plate protrusions 520 and 530 protrude from the plate body 510 in the X-axis direction (first direction) and are portions that face the energy storage element 100 on both sides in the Z-axis direction (second direction intersecting the first direction). Specifically, the plate protrusion 520 is a long, flat portion that protrudes in the X-axis direction from the Z-axis positive end of the plate body 510 toward the energy storage element 100 and extends in the Y-axis direction, and is positioned in the Z-axis positive direction of the energy storage element 100. In this embodiment, the plate protrusion 520 is positioned in the Z-axis direction, sandwiching the insulating protrusion 620 of the insulating member 600, which will be described later, between the multiple energy storage elements 100 and the multiple spacers 200. Specifically, the plate protrusion 520 is positioned in a state in which it is inserted into and fitted into the insulating protrusion 620 from the X-axis direction (see Figure 5, etc.).

[0036] The plate projection 530 is a long, flat portion that protrudes in the X-axis direction toward the energy storage element 100 from the Z-axis negative end of the plate body 510 and extends in the Y-axis direction, and is positioned in the Z-axis negative direction of the energy storage element 100. In this embodiment, the plate projection 530 is positioned between the multiple energy storage elements 100 and the multiple spacers 200 to sandwich the insulating projection 630 of the insulating member 600, which will be described later. Specifically, the plate projection 530 is positioned in contact with the insulating projection 630 in the Z-axis direction (see Figure 5, etc.). The plate projection 530 is longer in the X-axis direction than the plate projection 520.

[0037] The insulating member 600 is a plate-shaped, elongated insulating member (insulator) that is positioned on both sides in the X-axis direction of the multiple energy storage elements 100 and the multiple spacers 200, and extends in the Y-axis direction. The insulating member 600 is positioned between the multiple energy storage elements 100 and the side plate 500 so as to straddle the multiple energy storage elements 100 and the multiple spacers 200. In this way, the insulating member 600 insulates the multiple energy storage elements 100 from the side plate 500. The insulating member 600 may be made of any material that has insulating properties, for example, it can be made of any insulating material that can be used for the spacers 200. In this embodiment, the insulating member 600 is a thin member (thin film) with a thickness of about a few tenths of a millimeter.

[0038] The insulating member 600 has an insulating body portion 610 and a pair of insulating protrusions 620 and 630 (see Figures 2 and 4, etc.). The insulating body portion 610 is positioned between the energy storage element 100 and the plate body portion 510, and is a flat, rectangular portion parallel to the YZ plane and extending in the Y-axis direction. Specifically, the insulating body portion 610 is positioned in the X-axis direction between the multiple energy storage elements 100 and the multiple spacers 200 and the plate body portion 510. The insulating body portion 610 is positioned opposite the central part of the energy storage element 100 (the central part of the short side 112 (the part including the center)) in the Z-axis direction (second direction) in the X-axis direction. Specifically, the insulating body portion 610 is positioned opposite the short side 112 of the energy storage element 100 in the X-axis direction, extending from one end to the other in the Z-axis direction. The insulating body 610 is positioned in contact with the side walls of the multiple spacers 200 in the X-axis direction in the X-axis direction. However, depending on the shape of the spacers 200, the insulating body 610 may be positioned in contact with the short side surface 112 of the energy storage element 100.

[0039] The pair of insulating protrusions 620 and 630 protrude from the insulating body 610 in the X-axis direction (first direction) and are positioned between the energy storage element 100 and the pair of plate protrusions 520 and 530 in the Z-axis direction (second direction). Specifically, the insulating protrusion 620 is a long, plate-shaped portion that protrudes in the X-axis direction from the Z-axis positive end of the insulating body 610 toward the energy storage element 100 and extends in the Y-axis direction. The insulating protrusion 620 is positioned in the Z-axis direction in contact with the upper wall in the Z-axis direction of the X-axis positive end of the multiple spacers 200 in the Z-axis positive direction of the multiple energy storage elements 100 and multiple spacers 200. Depending on the shape of the spacers 200, the insulating protrusion 620 may be positioned in contact with the X-axis positive end of the cover 130 of the energy storage element 100.

[0040] The insulating projection 630 is a long, flat portion that protrudes in the X-axis direction toward the energy storage element 100 from the Z-axis negative end of the insulating body portion 610 and extends in the Y-axis direction. The insulating projection 630 is positioned in contact with the Z-axis direction of the bottom wall in the Z-axis direction of the X-axis end of the multiple energy storage elements 100 and multiple spacers 200 in the Z-axis negative direction. Depending on the shape of the spacer 200, the insulating projection 630 may be positioned in contact with the X-axis end of the bottom surface 113 of the energy storage element 100. The insulating projection 630 is longer in the X-axis direction than the insulating projection 620. A more detailed explanation of the configuration of the insulating member 600 will be given later.

[0041] [2. Description of the energy storage element 100] Next, the configuration of the energy storage element 100 will be described in detail. Figure 3 is a perspective view showing the configuration of the energy storage element 100 according to this embodiment. Figure 3 shows an enlarged view of the appearance of one of the multiple energy storage elements 100 shown in Figure 2. Since all of the multiple energy storage elements 100 have the same configuration, the configuration of one energy storage element 100 will be described in detail below.

[0042] As shown in Figure 3, the energy storage element 100 comprises a container 110, a pair of electrode terminals 140 (positive and negative sides), and an upper gasket 150. Inside the container 110 are a lower gasket, electrode bodies, a pair of current collectors (positive and negative sides), and an electrolyte (non-aqueous electrolyte), but these are not shown in the illustration. There are no particular restrictions on the type of electrolyte as long as it does not impair the performance of the energy storage element 100, and various types can be selected.

[0043] In addition to the above-mentioned components, the energy storage element 100 may also have spacers positioned to the side or below the electrode body, and an insulating film that encloses the electrode body, etc. Furthermore, an insulating film (such as a shrink tube) may be placed around the container 110 to cover the outer surface of the container 110. The material of the insulating film is not particularly limited as long as it can ensure the necessary insulation for the energy storage element 100, but examples include insulating resins such as PC, PP, PE, PPS, PET, PBT, or ABS resin, epoxy resin, Kapton®, Teflon®, silicon, polyisoprene, and polyvinyl chloride.

[0044] The container 110 is a rectangular parallelepiped (square or box-shaped) case having a container body 120 with an opening formed therein and a lid 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 formed on the Z-axis positive side. The lid 130 is a rectangular plate-shaped member that constitutes the lid of the container 110, and is arranged extending in the X-axis direction in the Z-axis positive direction of the container body 120. The container 110 (lid 130) may be provided with a gas discharge valve to release pressure when the pressure inside the container 110 rises excessively, and an injection part for injecting electrolyte into the container 110. The material of the container 110 (container body 120 and lid 130) is not particularly limited and can be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0045] The container 110 has a structure in which the inside is sealed by welding or the like to the container body 130 after the electrode body and the like 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 on the Z-axis negative side. The long sides 111 are rectangular planar portions that form the long sides of the container 110 and are positioned opposite to 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 portions that form the short sides of the container 110 and are positioned opposite to the side plates 500 and insulating members 600 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 flat surface that forms the bottom of the container 110, and is located adjacent to the long side surface 111 and the short side surface 112.

[0046] The electrode terminals 140 are terminal members (positive and negative electrode terminals) of the energy storage element 100, which is placed on the cover 130, and are electrically connected to the positive and negative electrode plates of the electrode body via a current collector. In other words, the electrode terminals 140 are metal members that lead the electricity stored in the electrode body to the external space of the energy storage element 100 and introduce electricity into the internal space of the energy storage element 100 to store electricity in the electrode body. The electrode terminals 140 are made of aluminum, aluminum alloy, copper, copper alloy, or the like.

[0047] 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 has a positive electrode active material layer formed on a positive electrode base layer which is a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate has a negative electrode active material layer formed on a negative electrode base layer which is a current collector foil made of a metal such as copper or a copper alloy. 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 laminated (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.

[0048] The current collector is a conductive member (positive electrode current collector and negative electrode current collector) that is electrically connected to the electrode terminal 140 and the electrode body. The positive electrode current collector is made of aluminum or an aluminum alloy, similar to the positive electrode base layer of the positive electrode plate, and the negative electrode current collector is made of copper or a copper alloy, similar to the negative electrode base layer of the negative electrode plate.

[0049] The upper gasket 150 is positioned between the cover 130 and the electrode terminal 140, and is a gasket that insulates and seals the space between the cover 130 and the electrode terminal 140. The lower gasket is positioned between the cover 130 and the current collector, and is a gasket that insulates and seals the space between the cover 130 and the current collector. The upper gasket 150 and the lower gasket may be made of any material that has insulating properties.

[0050] [3. Explanation of insulating material 600] Next, the configuration of the insulating member 600 will be described in detail. Figure 4 is a perspective view showing the configuration of the insulating member 600 according to this embodiment. Specifically, Figure 4(a) is a perspective view showing an enlarged view of the insulating member 600 in the positive X-axis direction, one of the pair of insulating members 600 shown in Figure 2. Figure 4(b) is a perspective view showing the configuration of the insulating member 600 shown in Figure 4(a) rotated 180° around the Z-axis.

[0051] Figure 5 is a cross-sectional view showing the configuration in which the insulating member 600 according to this embodiment is attached to the side plate 500. Specifically, Figure 5(a) shows a cross-section of the insulating member 600 attached to the side plate 500, with components other than the side plate 500 and the insulating member 600 omitted, and cut by a plane parallel to the XZ plane. Figure 5(a) shows the state in which the insulating member 600 and side plate 500 in the positive X-axis direction of the pair of insulating members 600 and pair of side plates 500 shown in Figure 2 are assembled. Figure 5(b) shows an enlarged view of the configuration of the insulating projection 630 of the insulating member 600 shown in Figure 5(a), and Figure 5(c) shows an enlarged view of the configuration of the bent portion 640 of the insulating member 600 shown in Figure 5(a).

[0052] The configurations of the pair of side plates 500 and the pair of insulating members 600 shown in Figure 2, specifically the configuration in the positive X-axis direction and the configuration in the negative X-axis direction, have a shape that is symmetrical with respect to the YZ plane. Therefore, in the following explanation, we will focus on the configuration in the positive X-axis direction as shown in Figures 4 and 5, and the explanation of the configuration in the negative X-axis direction will be simplified or omitted.

[0053] As shown in Figures 4 and 5, the insulating member 600 has a bent portion 640 between the insulating body portion 610 and the insulating protrusion portion 630, in addition to the insulating body portion 610 and the insulating protrusion portion 620 and 630 described above. The configuration of the insulating protrusion portion 620 and 630 and the bent portion 640 will be described in detail below.

[0054] The insulating projection 620 is positioned to sandwich the plate projection 520 in the Z-axis direction. In other words, the insulating projection 620 protrudes from the Z-axis positive end of the insulating body 610 in the X-axis negative direction, bends in the Z-axis positive direction, and has a roughly C-shaped cross-section when viewed from the Y-axis negative direction. As a result, an opening 621 is formed in the insulating projection 620 that opens in the X-axis positive direction, and the plate projection 520 is inserted into and fitted into this opening 621, thereby attaching the insulating projection 620 to the plate projection 520. The opening 621 is a bag-shaped recess in which the X-axis positive surface of the insulating projection 620 is recessed in the X-axis negative direction and extends in the Y-axis direction. The insulating projection 620 has a shape in which the tip (opening end of the opening 621) in the Z-axis positive direction and X-axis positive direction is curved in the Z-axis positive direction, making it easy to insert the plate projection 520 into the opening 621.

[0055] The insulating projection 630 has a groove 631, a protrusion 632, and a first thin-walled portion 633. The groove 631 is a recess that is recessed in the Z-axis direction (second direction) away from the energy storage element 100 (negative Z-axis direction) and extends in the Y-axis direction (third direction intersecting the first and second directions). The groove 631 is formed continuously from one end to the other in the Y-axis direction of the insulating projection 630. In this embodiment, the groove 631 is a recess with a width of about 5 mm in the X-axis direction and a depth of about 2 mm in the Z-axis direction, and its cross-sectional shape in the XZ plane is curved (approximately a semicircular arc shape). However, the groove 631 is not particularly limited in its cross-sectional shape, as it only needs to be a groove-shaped recess extending in the Y-axis direction.

[0056] The protrusion 632 is a protrusion on the surface opposite to the groove 631, projecting away from the energy storage element 100 in the Z-axis direction (second direction) (negative Z-axis direction), and extending in the Y-axis direction (third direction). The protrusion 632 is formed continuously from one end to the other in the Y-axis direction of the insulating protrusion 630 at a position opposite the groove 631 in the Z-axis direction. In this embodiment, the protrusion 632, like the groove 631, is a protrusion with a width of about 5 mm in the X-axis direction and a height of about 2 mm in the Z-axis direction, and has a curved cross-sectional shape (approximately a semicircular arc shape) in the XZ plane. The cross-sectional shape of the protrusion 632 is not particularly limited, but it is preferable that it has a shape similar to (similar to) the groove 631. In other words, by curving the insulating protrusion 630 so that it protrudes in the negative Z-axis direction, a bulging portion consisting of the protrusion 632 and the groove 631 is formed.

[0057] The protrusion 632 (and groove 631) is positioned in the X-axis direction (first direction) at a location further away from the insulating body portion 610 than the plate projection 530 (in the negative X-axis direction of the plate projection 530). In other words, the portion of the insulating projection 630 that is in the positive X-axis direction than the protrusion 632 (and groove 631) abuts against the plate projection 530, while the protrusion 632 (and groove 631) and the portion that is in the negative X-axis direction further protrude from the plate projection 530 in the negative X-axis direction. The protrusion 632 (and groove 631) is positioned adjacent to the plate projection 530 in the X-axis direction. In this embodiment, the protrusion 632 is positioned slightly away from the plate projection 530, but it may also be positioned in contact with the end face of the plate projection 530 in the negative X-axis direction.

[0058] The first thin-walled portion 633 is positioned in the Y-axis direction (third direction) at a location that overlaps with the groove portion 631 when viewed from the Z-axis direction (second direction), and is a thin-walled portion that is thinner than the adjacent portion. The first thin-walled portion 633 is positioned extending from one end to the other in the Y-axis direction of the insulating projection portion 630. The first thin-walled portion 633 is formed to be thinner than the adjacent portion by forming a cut in the surface of the groove portion 631 that faces the energy storage element 100 (the surface in the positive Z-axis direction). Specifically, the first thin-walled portion 633 is formed by continuously cutting out and recessing the central part of the groove portion 631 in the X-axis direction from one end to the other in the Y-axis direction of the groove portion 631. In this embodiment, the cut is a V-shaped groove in the XZ plane with a depth of about 0.1 mm in the Z-axis direction. In other words, the notch is a second groove formed in the groove 631. The cross-sectional shape of the notch is not particularly limited and may be rectangular, curved, linear, etc. The position where the notch is formed is also not particularly limited.

[0059] The bent portion 640 is the boundary portion (bent portion) between the insulating main body portion 610 and the insulating protrusion portion 630, located between the insulating main body portion 610 and the insulating protrusion portion 630. The bent portion 640 is positioned extending in the Y-axis direction along the boundary portion (bent portion) between the plate main body portion 510 and the plate protrusion portion 530. In this embodiment, the bent portion 640 is positioned in contact with the boundary portion (bent portion) between the plate main body portion 510 and the plate protrusion portion 530 in the negative X-axis direction and the positive Z-axis direction, but contact is not required.

[0060] The bent portion 640 has a recess 641, a protrusion 642, and a second thin-walled portion 643. The recess 641 is recessed in the direction away from the energy storage element 100 in the X-axis and Z-axis directions (positive X-axis direction and negative Z-axis direction), and extends in the Y-axis direction. The recess 641 is formed continuously from one end to the other in the Y-axis direction of the bent portion 640. In this embodiment, the recess 641 is a recess with a curved (arc-shaped) cross-sectional shape in the XZ plane, but the recess 641 only needs to be a recess that extends in the Y-axis direction, and its cross-sectional shape is not particularly limited.

[0061] The protrusion 642 is a protrusion that projects from the surface opposite to the recess 641 in the direction away from the energy storage element 100 in the X-axis direction and the Z-axis direction (positive X-axis direction and negative Z-axis direction), and extends in the Y-axis direction. The protrusion 642 is formed continuously from one end to the other in the Y-axis direction of the bent portion 640 at a position opposite to the recess 641 in the X-axis direction and the Z-axis direction. In this embodiment, the protrusion 642 is a protrusion with a curved (arc-shaped) cross-sectional shape in the XZ plane, similar to the recess 641. The cross-sectional shape of the protrusion 642 is not particularly limited, but it is preferable that it has a shape similar to (similar to) the recess 641. In other words, by curving the boundary portion of the insulating body portion 610 and the insulating protrusion portion 630 so that it protrudes in the positive X-axis direction and the negative Z-axis direction, a bulging bent portion 640 consisting of the protrusion 642 and the recess 641 is formed.

[0062] In this embodiment, the recess 641 and the protrusion 642 are formed in the state before the boundary portion of the insulating body portion 610 and the insulating projection portion 630 is bent (the state in which the insulating body portion 610 and the insulating projection portion 630 are located on the same plane). In this state, the bent portion 640 is formed by bending the boundary portion of the insulating body portion 610 and the insulating projection portion 630 at the positions of the recess 641 and the protrusion 642. In other words, the recess 641 and the protrusion 642 have the same function as the groove portion 631 and the protrusion 632 of the insulating projection portion 630.

[0063] The second thin-walled portion 643 is a thin-walled portion that extends in the Y-axis direction (third direction) at the boundary portion (bent portion) between the insulating main body portion 610 and the insulating protrusion portion 630, and is thinner than the adjacent portion. The second thin-walled portion 643 extends from one end to the other in the Y-axis direction of the bent portion 640. The second thin-walled portion 643 is formed to be thinner than the adjacent portion by forming a cut in the surface of the recess 641 facing the energy storage element 100 (the surface in the negative X-axis direction and positive Z-axis direction). Specifically, the second thin-walled portion 643 is formed by continuously cutting out and recessing the central part of the recess 641 in the X-axis direction (central part in the Z-axis direction) from one end to the other in the Y-axis direction of the recess 641. The shape of the cut is not particularly limited, but in this embodiment, the cut has the same shape as the cut of the first thin-walled portion 633. The position where the cut is formed is not particularly limited.

[0064] [4. Explanation of Effects] As described above, according to the energy storage device 10 of the present invention, the insulating protrusion 630 of the insulating member 600 is positioned between the energy storage element 100 and the plate protrusion 530 of the side plate 500. The insulating protrusion 630 has a groove 631 that is recessed in the direction away from the energy storage element 100 and extends in the Y-axis direction (third direction). In this way, because the insulating protrusion 630 has a groove 631 that is recessed in the direction away from the energy storage element 100, the bending (bending) of the insulating protrusion 630 toward the energy storage element 100 is suppressed. As a result, the insulating protrusion 630 does not get in the way when assembling the side plate 500 to the energy storage element 100, thereby improving the workability of the assembly work of the side plate 500 to the energy storage element 100.

[0065] In the insulating member 600, the insulating body portion 610, which is positioned between the energy storage element 100 and the plate body portion 510, is positioned opposite the center of the energy storage element 100 in the Z-axis direction (second direction). This improves the insulation between the energy storage element 100 and the side plate 500 (plate body portion 510).

[0066] In the insulating member 600, the first thin-walled portion 633 is formed at a position overlapping with the groove portion 631 of the insulating projection 630, which further suppresses the bending (bending) of the insulating projection 630 toward the energy storage element 100. This further improves the workability of assembling the side plate 500 to the energy storage element 100.

[0067] In the insulating member 600, the first thin-walled portion 633 can be easily formed by forming a notch in the groove 631 of the insulating projection 630. Furthermore, by forming a notch on the surface of the groove 631 facing the energy storage element 100 to form the first thin-walled portion 633, the bending (warping) of the insulating projection 630 toward the energy storage element 100 is further suppressed. This further improves the workability of assembling the side plate 500 to the energy storage element 100.

[0068] In the insulating member 600, by curving the insulating projection 630 to form a groove 631, a convex portion 632 is formed on the opposite side of the groove 631. Therefore, by configuring the insulating projection 632 to be formed on the surface of the insulating projection 630 opposite to the groove 631, the groove 631 can be easily formed. By positioning the convex portion 632 further away from the insulating body portion 610 than the plate projection 530 of the side plate 500, it is possible to suppress the convex portion 632 from overlapping with the plate projection 530 in the Z-axis direction (second direction) and increasing the size in the Z-axis direction (second direction). By positioning the convex portion 632 to abut against the plate projection 530 in the X-axis direction (first direction), the insulating projection 630 can be positioned relative to the plate projection 530 in the X-axis direction (first direction), and movement of the insulating projection 630 in the X-axis direction (first direction) can be suppressed.

[0069] By forming a second thin-walled portion 643 at the bent portion 640, which is the boundary between the insulating main body portion 610 and the insulating protrusion portion 630 of the insulating member 600, it is possible to suppress the bending (warping) of the insulating protrusion portion 630 toward the energy storage element 100 relative to the insulating main body portion 610, even at the bent portion 640. This further improves the workability of the assembly work of the side plate 500 to the energy storage element 100. The recessed portion 641 and convex portion 642 of the bent portion 640 have the same effect as the grooved portion 631 and convex portion 632 of the insulating protrusion portion 630.

[0070] [5 Explanation of variations] Although the energy storage device 10 according to this embodiment has been described above, the present invention is not limited to the above embodiment. 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.

[0071] (Variation 1) In the above embodiment, the insulating projection 630 of the insulating member 600 is formed by creating a single cut in the center of the groove 631 in the X-axis direction to form the first thin-walled portion 633, but the embodiment is not limited to this. Figures 6A and 6B are cross-sectional views showing the configuration of insulating projections 630a and 630b of the insulating member 600 according to Modification 1 of this embodiment. Figures 6A and 6B correspond to Figure 5(b).

[0072] As shown in Figure 6A, the insulating projection 630a has two first thin-walled portions 633 formed by two cuts in the groove 631. The two first thin-walled portions 633 are positioned equidistant from the center position of the groove 631 in the X-axis direction. The number of first thin-walled portions 633 is not limited to two; three or more first thin-walled portions 633 may be formed. The formation positions of the first thin-walled portions 633 are also not particularly limited. The other configurations of this modified example are the same as those of the above embodiment, so a detailed explanation is omitted.

[0073] As shown in Figure 6B, a first thin-walled portion 633a is formed in the insulating projection 630b by forming a notch in the convex portion 632 (the surface opposite to the energy storage element 100, the surface in the negative Z-axis direction). The first thin-walled portion 633a has a shape similar to the first thin-walled portion 633 in the above embodiment, but inverted in the Z-axis direction (rotated 180° around the Y-axis). As with the insulating projection 630a described above, multiple first thin-walled portions 633a may be formed in the insulating projection 630b. The formation position of the first thin-walled portions 633a is not particularly limited. The other configurations of this modified example are the same as in the above embodiment, so a detailed explanation is omitted.

[0074] As described above, the energy storage device 10 according to this modified example can achieve the same effects as the embodiment described above. In particular, when multiple first thin-walled portions 633 are formed, such as the insulating protrusion 630a, the bending (warping) of the insulating protrusion 630a toward the energy storage element 100 can be further suppressed, thereby further improving the workability of assembling the side plate 500 to the energy storage element 100.

[0075] (Modification 2) In the above embodiment, the bent portion 640 of the insulating member 600 has a recess 641 and a protrusion 642 as shown in Figure 5(c), but the shape of the recess 641 and the protrusion 642 is not limited. Figure 7 is a cross-sectional view showing the configuration of the bent portion 640a of the insulating member 600 according to a modified example 2 of this embodiment. Figure 7 is a diagram corresponding to Figure 5(c).

[0076] As shown in Figure 7, the bent portion 640a has grooves 641a and protrusions 642a instead of the recesses 641 and protrusions 642 in the above embodiment. The grooves 641a and protrusions 642a have a shape that is like the grooves 631 and protrusions 632 of the insulating projection 630 in the above embodiment rotated by 45° around the Y axis. The other configurations of this modified example are the same as in the above embodiment, so a detailed explanation is omitted.

[0077] As described above, the energy storage device 10 according to this modified example can achieve the same effects as the embodiment described above. In particular, since the bent portion 640a has a groove portion 641a, the bending (bending) of the insulating protrusion 630 toward the energy storage element 100 can be further suppressed, and the workability of assembling the side plate 500 to the energy storage element 100 can be further improved.

[0078] (Other variations) In the above embodiment, the insulating member 600 is provided with a pair of insulating protrusions 620 and 630, but it is not required to have the insulating protrusion 620. Similarly, the side plate 500 is not required to have the plate protrusion 520.

[0079] In the above embodiment, the insulating projection 630 of the insulating member 600 has a groove 631, but the insulating projection 620 may have a groove with the same configuration as the groove 631. When the energy storage element 100 is placed upside down and the side plate 500 is assembled to the energy storage element 100, the insulating projection 620 can be prevented from bending (bending) toward the energy storage element 100.

[0080] In the above embodiment, the insulating projection 630 is provided with one groove 631, but it may also be provided with multiple grooves 631.

[0081] In the above embodiment, the groove 631 of the insulating projection 630 is formed continuously from one end to the other in the Y-axis direction of the insulating projection 630. However, it may be formed intermittently, or it may be formed only on a part of the insulating projection 630 in the Y-axis direction. The same applies to the convex portion 632, the first thin-walled portion 633, and the second thin-walled portion 643 of the bent portion 640.

[0082] In the above embodiment, the groove 631 and protrusion 632 of the insulating projection 630 are positioned further away from the insulating body 610 than the plate projection 530, but they may also be positioned to overlap with the plate projection 530 in the Z-axis direction.

[0083] In the above embodiment, the first thin-walled portion 633 of the insulating projection 630 may be a cut that penetrates the insulating projection 630. In other words, the first thin-walled portion 633 may be a portion of the insulating projection 630 with a thickness of 0, and multiple such first thin-walled portions 633 may be formed intermittently on the insulating projection 630. The same applies to the second thin-walled portion 643.

[0084] In the above embodiment, the first thin-walled portion 633 is positioned to overlap with the groove portion 631 when viewed from the Z-axis direction. However, it may be positioned at a different location from the groove portion 631, such as in the positive or negative X-axis direction of the groove portion 631.

[0085] In the above embodiment, the insulating projection 630 has a protrusion 632 on the opposite side of the groove 631, but it may not have a protrusion 632 and the opposite side of the groove 631 may be a flat surface. The insulating projection 630 may not have a first thin-walled portion 633. Similarly, the bent portion 640 may not have a second thin-walled portion 643.

[0086] In the above embodiment, the side plate 500 is a member that connects a pair of end plates 400, but it can be any member that is positioned to the side of the energy storage element 100, and its configuration is not particularly limited.

[0087] In the above embodiment, both the configuration in the positive X-axis direction and the configuration in the negative X-axis direction of the energy storage device 10 are assumed to have the above-described configurations, but either one may have a configuration different from that described above.

[0088] The present invention also includes forms constructed by arbitrarily combining the components included in the above embodiments and their modified forms. In other words, among the various modifications that can be applied to the above embodiments, those that can also be applied to modified forms 1 and 2 may also be applied to modified forms 1 and 2. Among the modifications of either modified form 1 or 2, those that can also be applied to other modified forms may also be applied to those other modified forms.

[0089] The present invention can be realized not only as such an energy storage device 10, but also as a combination of the side plate 500 and the insulating member 600, or as the insulating member 600 alone. [Industrial applicability]

[0090] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of Symbols]

[0091] 10 Energy storage device 100 energy storage elements 110 Container 140 Electrode terminal 200 Spacer 400 End Plate 500 Side Plate 510 Plate body 520, 530 Plate protrusions 600 Insulating material 610 Insulated main body 620, 630, 630a, 630b Insulated protrusions 621 Opening 631, 641a Groove 632, 642, 642a protrusions 633, 633a First thin section 640, 640a Bent section 641 recess 643 Second thin section

Claims

1. A power storage device comprising: a power storage element; a side plate positioned to the side of the power storage element in a first direction; and an insulating member positioned between the power storage element and the side plate, The aforementioned side plate is A plate body portion facing the energy storage element in the first direction, The plate has a plate projection that protrudes from the plate body in the first direction and faces the energy storage element in a second direction that intersects with the first direction, The insulating member is An insulating body portion is disposed between the energy storage element and the plate body portion, It has an insulating projection that protrudes from the insulating body in the first direction and is positioned between the energy storage element and the plate projection in the second direction, The insulating protrusion is, A groove that is recessed in the second direction away from the energy storage element and extends in a third direction intersecting the first and second directions, It has a protrusion positioned on the surface opposite to the groove, which protrudes in the direction away from the energy storage element in the second direction and extends in the third direction, The insulating protrusion is not connected to the member located on the opposite side of the insulating body of the energy storage element in the first direction. Energy storage device.

2. The insulating body is positioned opposite the central part of the energy storage element in the second direction. The energy storage device according to claim 1.

3. The insulating projection extends in the third direction at a position that overlaps with the groove when viewed from the second direction, and has a first thin-walled portion that is thinner than the adjacent portion. The energy storage device according to claim 1 or 2.

4. The first thin-walled portion is formed with a cut on the surface of the groove facing the energy storage element, so that it is thinner than the portion adjacent to the first thin-walled portion. The energy storage device according to claim 3.

5. The protrusion is positioned in the first direction at a location further away from the insulating body than the plate protrusion. The energy storage device according to claim 1 or 2.

6. The insulating member has a second thin-walled portion extending in the third direction at the boundary between the insulating body portion and the insulating projection portion, which is thinner than the adjacent portion. The energy storage device according to claim 1 or 2.

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