Energy storage device

Abstract

To provide a power storage device with which it is possible to easily arrange power storage elements in the inside of an outer packaging.SOLUTION: Provided is a power storage device 10 comprising a plurality of power storage elements 100 and an outer packaging 200 in which the plurality of power storage elements 100 are accommodated. The plurality of power storage elements 100 include a first power storage element 101 and a second power storage element 102 which are arranged side by side in a first direction (Y axis direction), and the outer packaging 200 includes a bottom wall 211 that faces the plurality of power storage elements 100 in a second direction (Z axis direction) orthogonal to the first direction, an opening 214 that opens facing a third direction (X axis direction) orthogonal to the first and second directions, and which the first power storage element 101 can pass through, and a guide part 211a which is located between the first power storage element 101 and the second power storage element 102, and which extends toward the opening 214.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a power storage device including a plurality of power storage elements and an exterior body that houses the plurality of power storage elements.

Background Art

[0002] Conventionally, a power storage device including a plurality of power storage elements and an exterior body that houses the plurality of power storage elements has been widely known. For example, Patent Document 1 discloses a battery pack (power storage device) in which a plurality of rectangular secondary batteries (power storage elements) are housed in a case body (exterior body).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power storage device configured as described above in the related art, a plurality of power storage elements are inserted through an opening facing the bottom wall of the exterior body (case body), so that the plurality of power storage elements are housed in the exterior body. In such a case, depending on the position, shape, size of the opening of the exterior body, or the configuration of the plurality of power storage elements, etc., it may be difficult to insert the plurality of power storage elements through the opening of the exterior body and it may take time, and thus it may be difficult to arrange the power storage elements in the exterior body.

[0005] The present invention has been made by newly focusing on the above problems by the inventor of the present application, and an object thereof is to provide a power storage device in which power storage elements can be easily arranged in an exterior body.

Means for Solving the Problems

[0006] An energy storage device according to one aspect of the present invention comprises a plurality of energy storage elements and an outer casing that houses the plurality of energy storage elements, wherein the plurality of energy storage elements have a first energy storage element and a second energy storage element arranged in a first direction, and the outer casing has a bottom wall facing the plurality of energy storage elements in a second direction perpendicular to the first direction, an opening that opens toward a third direction perpendicular to the first and second directions, through which the first energy storage element can pass, and a guide portion disposed between the first energy storage element and the second energy storage element and extending toward the opening. [Effects of the Invention]

[0007] According to the energy storage device of the present invention, the energy storage element can be easily arranged inside the outer casing. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the configuration of the energy storage device according to the embodiment. [Figure 2] This is a perspective view showing the configuration of the energy storage element according to the embodiment. [Figure 3] This is a perspective view showing the configuration of the exterior body according to the embodiment. [Figure 4] This figure shows the process of housing multiple energy storage elements according to the embodiment inside the outer casing (the process of inserting the first energy storage element through the opening of the outer casing body). [Figure 5] This figure shows the process of housing multiple energy storage elements according to the embodiment inside the outer casing (the process of housing the first energy storage element in the outer casing body and then inserting the second energy storage element through the opening). [Figure 6] This figure shows the process of housing multiple energy storage elements according to the embodiment inside the outer casing (the state after all energy storage elements have been housed in the outer casing). [Figure 7] This is a perspective view showing the configuration of a power storage device according to a modified example 1 of the embodiment. [Modes for carrying out the invention]

[0009] An energy storage device according to one aspect of the present invention comprises a plurality of energy storage elements and an outer casing that houses the plurality of energy storage elements, wherein the plurality of energy storage elements have a first energy storage element and a second energy storage element arranged in a first direction, and the outer casing has a bottom wall facing the plurality of energy storage elements in a second direction perpendicular to the first direction, an opening that opens toward a third direction perpendicular to the first and second directions, through which the first energy storage element can pass, and a guide portion disposed between the first energy storage element and the second energy storage element and extending toward the opening.

[0010] According to this, in the energy storage device, the outer casing has an opening that opens toward a third direction, through which a first energy storage element can pass, and a guide portion that is positioned between the first and second energy storage elements, which are aligned in the first direction, and extends toward the opening. In this way, the outer casing is provided with an opening through which a first energy storage element can pass, and a guide portion that extends toward the opening is provided between the first and second energy storage elements. This allows the first energy storage element to be easily inserted into the outer casing through the opening by the guide portion, and the first energy storage element to be easily positioned alongside the second energy storage element. Therefore, in the energy storage device, the energy storage element (first energy storage element) can be easily positioned inside the outer casing.

[0011] The guide portion may be a protrusion that extends from the bottom wall in the second direction.

[0012] According to this, by forming the guide portion on the exterior body so that it protrudes from the bottom wall, the guide portion can be easily formed on the exterior body.

[0013] The first energy storage element has a pair of electrode terminals that are aligned in the third direction when viewed from the second direction, and the guide portion may extend in the direction of the alignment of the pair of electrode terminals when viewed from the second direction.

[0014] When inserting the energy storage element from the bottom surface or the electrode terminal side, there is a risk that the bottom surfaces and electrode terminals of the two energy storage elements may come into contact and cause a short circuit. Therefore, the guide portion is arranged to extend in the arrangement direction of the pair of electrode terminals as viewed from the second direction. Thereby, since the first energy storage element can be inserted in the arrangement direction of the pair of electrode terminals, it is difficult for the bottom surfaces and electrode terminals of the first energy storage element and the second energy storage element to come into contact. Therefore, it is possible to suppress the bottom surfaces and electrode terminals of the two energy storage elements from coming into contact and causing a short circuit.

[0015] The first energy storage element has a shape that is long in the third direction as viewed from the second direction, and the guide portion may extend in the longitudinal direction of the first energy storage element as viewed from the second direction.

[0016] According to this, by arranging the guide portion to extend in the longitudinal direction of the first energy storage element as viewed from the second direction, the first energy storage element can be inserted in the longitudinal direction. Thereby, since the first energy storage element can be inserted from the other end while gripping one end in the longitudinal direction, the first energy storage element can be easily inserted into the exterior body.

[0017] The plurality of energy storage elements includes an energy storage element group composed of a plurality of energy storage elements arranged in the third direction including the first energy storage element, and the guide portion may extend from the energy storage element located at one end in the third direction of the energy storage element group to the energy storage element located at the other end.

[0018] According to this, by arranging the guide portion to extend across the energy storage elements located at both ends in the third direction of the energy storage element group, the energy storage element group can be easily inserted into the exterior body by the guide portion.

[0019] Hereinafter, a power storage device according to an embodiment (including its modified examples) of the present invention will be described with reference to the drawings. The embodiments described below are all illustrative of comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. In each figure, dimensions and the like are not strictly illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0020] In the following description and the drawings, the arrangement direction of a pair of electrode terminals of the power storage element, the opposing direction of a pair of short side surfaces in the container of the power storage element, the longitudinal direction of the power storage element when viewed from above and below, the extending direction of the guide portion of the exterior body, or the arrangement direction of the exterior body main body and the lid body of the exterior body is defined as the X-axis direction. The opposing direction of a pair of long side surfaces in the container of the power storage element, the thickness direction (flat direction) of the container of the power storage element, or the arrangement direction of a plurality of guide portions is defined as the Y-axis direction. The protruding direction of the electrode terminals of the power storage element, the arrangement direction of the container main body and the container lid portion of the power storage element, the opposing direction of the bottom wall of the exterior body main body, 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 (orthogonal in this embodiment) with each other. Although it is conceivable that the Z-axis direction may not be the vertical direction depending on the usage mode, hereinafter, for the sake of convenience of explanation, the Z-axis direction will be described as the vertical direction.

[0021] In the following explanation, the X-axis positive direction refers to the direction of the X-axis arrow, and the X-axis negative direction refers to the opposite direction. When simply 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 direction and the Z-axis direction. In the following, the Y-axis direction will also be referred to as the first direction, the Z-axis direction as the second direction, and the X-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. In the following explanation, when the term "insulation" is used, it means "electrical insulation".

[0022] (Embodiment) [1. Description of the energy storage device 10] The configuration of the energy storage device 10 in this embodiment will now be described. Figure 1 is a perspective view showing the configuration of the energy storage device 10 according to this embodiment.

[0023] The energy storage device 10 is a device that can charge electricity from an external source and discharge electricity to an external source. 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, maglev trains, 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.

[0024] As shown in Figure 1, the energy storage device 10 comprises a plurality of energy storage elements 100 and an outer casing 200 that houses the plurality of energy storage elements 100. The energy storage device 10 also includes busbars that connect 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, a cover that closes the opening 201 of the outer casing 200, and electrical equipment such as a circuit board and relays for monitoring or controlling the charging and discharging states of the energy storage elements 100. The energy storage device 10 may also be equipped with external terminals, such as a terminal block for external terminals (positive external terminals and negative external terminals) for electrically connecting to external devices, which is attached to the outer casing 200, and the external terminals are arranged on the terminal block.

[0025] The number of energy storage elements 100 arranged inside the outer casing 200 is not particularly limited, but in this embodiment, 18 energy storage elements 100 are arranged inside the outer casing 200. Specifically, inside the outer casing 200, six groups (six sets) of energy storage element groups 100a, each consisting of three energy storage elements 100 aligned in the X-axis direction, are arranged in the Y-axis direction. The configuration of the energy storage elements 100 and the outer casing 200 will be described in detail below.

[0026] [1.1 Description of the energy storage element 100] First, the configuration of the energy storage element 100 will be described in detail. Figure 2 is a perspective view showing the configuration of the energy storage element 100 according to this embodiment. Since all energy storage elements 100 provided in the energy storage device 10 have the same configuration, Figure 2 shows one energy storage element 100.

[0027] 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. The energy storage element 100 has a shape that is elongated in the X-axis direction (third direction) when viewed from the Z-axis direction (second direction). In this embodiment, the energy storage element 100 has a flattened rectangular parallelepiped shape (square, prism) in the Y-axis direction. 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 can use the stored electricity without the user having to charge it. 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.

[0028] As shown in Figure 2, the energy storage element 100 comprises a container 110 and a pair of electrode terminals 150 (positive and negative). Inside the container 110 are an electrode body 160 and a pair of current collectors 170 (positive and negative). An electrolyte (non-aqueous electrolyte) is also sealed inside the container 110, and a gasket is placed between the electrode terminals 150 and current collectors 170 and the container 110 (container lid 130, described later), 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. The gasket may be made of any material as long as it has insulating properties. In addition to the above components, the energy storage element 100 may also have spacers placed to the side or below the electrode body 160, an insulating film enclosing the electrode body 160, and an insulating film (shrink tubing, etc.) covering the outer surface of the container 110.

[0029] The container 110 is a flat rectangular parallelepiped (square or box-shaped) case having a container body 120 with an opening and a container 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 on the Z-axis positive side. The container lid 130 is a rectangular plate-shaped member that is long in the X-axis direction and constitutes the lid of the container 110, and is positioned in the Z-axis positive direction of the container body 120. The container 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 container 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.

[0030] The container 110 is sealed inside by welding or other means to the container body 120 after the electrode body 160 and other components are housed inside the container body 120. The container 110 has a pair of long sides 111 and 112 on both sides in the Y-axis direction, a pair of short sides 113 and 114 on both sides in the X-axis direction, a bottom surface 115 on the Z-axis negative side, and a terminal arrangement surface 116 on the Z-axis positive side where the electrode terminals 150 are arranged. Thus, the container 110 is a flattened container in the Y-axis direction, with its thickness direction being the Y-axis direction, and has a shape that is long in the X-axis direction (third direction) when viewed from the Z-axis direction (second direction).

[0031] The electrode terminals 150 are terminal members (positive and negative electrode terminals) of the energy storage element 100, positioned on the container lid portion 130 of the container 110. Specifically, a pair of electrode terminals 150, aligned in the X-axis direction (third direction) when viewed from the Z-axis direction (second direction), are positioned protruding in the positive Z-axis direction from the terminal arrangement surface 116 (container lid portion 130) of the container 110. The electrode terminals 150 are electrically connected to the positive and negative electrode plates of the electrode body 160 via the current collector 170. In other words, the electrode terminals 150 are metallic members that guide the electricity stored in the electrode body 160 to the external space of the energy storage element 100, and also introduce electricity into the internal space of the energy storage element 100 to store electricity in the electrode body 160. The electrode terminals 150 are made of aluminum, aluminum alloy, copper, copper alloy, etc.

[0032] The electrode body 160 is an energy storage element (power generation element) capable of storing electricity, and comprises a positive electrode plate, a negative electrode plate, and a separator, which are formed by laminating the positive electrode plate, negative electrode plate, and separator. The positive electrode plate is an electrode plate on which a positive electrode active material layer is formed on a positive electrode substrate, which is a strip-shaped current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is an electrode plate on which a negative electrode active material layer is formed on a negative electrode substrate, which is a strip-shaped current collector foil made of a metal such as copper or a copper alloy. The separator is a microporous sheet made of resin. As for the positive electrode active material used in the positive electrode active material layer and the negative electrode active material used in the negative electrode active material layer, any known material can be used as long as it is capable of intercepting and releasing lithium ions. Similarly, any known material can be used for the separator as long as it does not impair the performance of the energy storage element 100.

[0033] In this embodiment, the electrode body 160 is a wound-type electrode body formed by winding layers of material arranged such that a separator is sandwiched between a positive electrode plate and a negative electrode plate. Specifically, the electrode body 160 has a positive electrode plate and a negative electrode plate wound around it with a separator in between, offset from each other in the direction of the winding axis (X-axis direction). The positive electrode plate and the negative electrode plate have portions at their respective offset ends where the composite material is not coated and the base material is exposed, and these ends are electrically and mechanically connected to the current collector 170. The electrode body 160 may also be a wound-type electrode body formed by winding a positive electrode plate, a negative electrode plate and a separator around a winding axis parallel to the Z-axis direction. The electrode body 160 may also be a stacked type electrode body formed by stacking multiple flat electrode plates, a bellows-type electrode body in which the electrode plates are folded in a bellows-like manner, or an electrode body of any other form.

[0034] The current collector 170 is a conductive current collector (positive electrode current collector and negative electrode current collector) positioned between the electrode body 160 and the container 110, and electrically connected to the electrode terminal 150 and the electrode body 160. The current collector 170 is joined to the electrode body 160 by welding or the like. The positive electrode current collector 170 is made of aluminum or an aluminum alloy, similar to the positive electrode base material of the positive electrode plate of the electrode body 160, and the negative electrode current collector 170 is made of copper or a copper alloy, similar to the negative electrode base material of the negative electrode plate of the electrode body 160.

[0035] [1.2 Description of the outer casing 200] Next, the configuration of the exterior body 200 will be described in detail using Figure 3. Figure 3 is a perspective view showing the configuration of the exterior body 200 according to this embodiment. Figure 3 shows the exterior body 210 and the lid 220 of the exterior body 200 separated.

[0036] The outer casing 200 is a rectangular parallelepiped (box-shaped) container that constitutes the outer casing of the energy storage device 10. The outer casing 200 is positioned outside the multiple energy storage elements 100, fixing the multiple energy storage elements 100 in predetermined positions and protecting them from impacts, etc. As shown in Figure 3, the outer casing 200 has an outer casing body 210 that constitutes the main body of the outer casing 200 and a lid 220 that constitutes the lid of the outer casing 200.

[0037] The outer casing 200 (outer casing body 210 and lid 220) is formed from insulating materials such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyetherether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or composite materials thereof. This prevents the multiple energy storage elements 100 from making electrical contact with conductive materials such as external metal components. However, if this is not necessary, the outer casing 200 may be made of a conductive material such as metal. The outer casing body 210 and lid 220 may be made of the same material or different materials.

[0038] The outer casing body 210 is a housing with an opening and accommodates multiple energy storage elements 100. The outer casing body 210 has a bottom wall 211 facing the Z-axis direction on the bottom surface in the negative Z-axis direction, a pair of side walls 212 facing the Y-axis direction on both sides in the Y-axis direction, and a side wall 213 facing the X-axis direction on the side surface in the negative X-axis direction. The outer casing body 210 is a single component in which the bottom wall 211, the pair of side walls 212, and the side walls 213 are integrated.

[0039] The bottom wall 211 is a flat, rectangular wall portion that forms the bottom surface of the outer casing body 210, and is parallel to the XY plane and elongated in the X-axis direction. The bottom wall 211 is positioned opposite the plurality of energy storage elements 100 in the Z-axis direction (a second direction perpendicular to the first direction). Specifically, the bottom wall 211 is positioned in the Z-axis direction of the plurality of energy storage elements 100 so as to cover the entire surface of the Z-axis direction of the plurality of energy storage elements 100, and supports the plurality of energy storage elements 100 from the Z-axis direction. The bottom wall 211 is adjacent to the pair of side walls 212 and side walls 213 and is integrated with the pair of side walls 212 and side walls 213.

[0040] The pair of side walls 212 are flat, rectangular wall portions parallel to the XZ plane and elongated in the X-axis direction, forming the Y-axis side surfaces of the outer casing body 210. The pair of side walls 212 are wall portions that rise in the Z-axis positive direction from both ends of the bottom wall 211 in the Y-axis direction, and are arranged opposite the plurality of energy storage elements 100 in the Y-axis direction. Specifically, the pair of side walls 212 are arranged in the Y-axis direction of the plurality of energy storage elements 100 so as to cover the entire surface of the Y-axis direction surface of the plurality of energy storage elements 100. In other words, the Y-axis positive side walls 212 are arranged in the Y-axis positive direction of the plurality of energy storage elements 100 so as to cover the entire surface of the Y-axis positive direction surface of the plurality of energy storage elements 100 in the Y-axis positive direction. The Y-axis negative side walls 212 are arranged in the Y-axis negative direction of the plurality of energy storage elements 100 so as to cover the entire surface of the Y-axis negative direction surface of the plurality of energy storage elements 100 in the Y-axis negative direction. The pair of side walls 212 are adjacent to the bottom wall 211 and the side wall 213.

[0041] The side wall 213 is a flat, rectangular wall portion that is parallel to the YZ plane and elongated in the Y-axis direction, forming the side surface of the outer casing body 210 in the negative X-axis direction. The side wall 213 is a wall portion that rises in the positive Z-axis direction from the negative X-axis end of the bottom wall 211 and is positioned opposite the multiple energy storage elements 100 in the X-axis direction. The side wall 213 is adjacent to the bottom wall 211 and the pair of side walls 212.

[0042] With the above configuration, the outer casing body 210 has an opening 201 that opens in the Z-axis direction and an opening 214 that opens in the X-axis direction (a third direction perpendicular to the first and second directions). In other words, the pair of side walls 212 and side wall 213 form the opening 201 that opens in the positive Z-axis direction, and the bottom wall 211 and the pair of side walls 212 form the opening 214 that opens in the positive X-axis direction.

[0043] The opening 201 is positioned opposite the bottom wall 211 of the outer casing body 210, and is a rectangular opening that is elongated in the X-axis direction when viewed from the Z-axis direction, opening in the Z-axis positive direction. In other words, the opening 201 is an opening on the Z-axis positive side of the outer casing body 210.

[0044] The opening 214 is positioned opposite the side wall 213 of the outer casing body 210, and is a rectangular opening that opens in the positive X-axis direction, and is elongated in the Y-axis direction when viewed from the X-axis direction. In other words, the opening 214 is an opening on the X-axis positive side of the outer casing body 210. The opening 214 has a smaller opening area than the opening 201, and is formed to be large enough for the energy storage elements 100 to pass through. The opening 214 is positioned opposite the energy storage elements 100. In other words, the opening 214 is positioned opposite the multiple energy storage elements 100 in the X-axis direction, and is formed to be large enough for the multiple energy storage elements 100 to pass through in the X-axis direction.

[0045] In this embodiment, the opening 201 is similarly formed to be large enough for multiple energy storage elements 100 to pass through, and is positioned opposite the multiple energy storage elements 100. In other words, the opening 201 is positioned opposite the multiple energy storage elements 100 in the Z-axis direction, and is formed to be large enough for multiple energy storage elements 100 to pass through in the Z-axis direction. In this embodiment, the opening 201 and the opening 214 are connected (linked). In other words, the opening 201 and the opening 214 are openings that open in different directions from one large opening.

[0046] The outer casing body 210 further has guide portions 211a and 211b. The guide portions 211a and 211b are elongated portions that extend toward the opening 214. In this embodiment, the guide portions 211a and 211b are protrusions that project from the bottom wall 211 in the Z-axis direction (second direction), and these protrusions extend in the X-axis direction (third direction). The guide portions 211a and 211b extend continuously in the X-axis direction (third direction) from one end to the other of the bottom wall 211 in the X-axis direction (from one end to the other of the outer casing 200 or the outer casing body 210). In this embodiment, the guide portions 211a and 211b are rectangular portions that are elongated in the X-axis direction and have a square shape when viewed from the X-axis direction, but they may have any shape, such as a semicircular shape, semi-elliptical shape, semi-elliptical shape, or triangular shape when viewed from the X-axis direction.

[0047] The outer casing body 210 has a plurality of guide portions 211a (five in this embodiment) arranged in the Y-axis direction, and two guide portions 211b located on both sides of the plurality of guide portions 211a in the Y-axis direction. The guide portions 211a are spaced apart from the side walls 212, while the guide portions 211b are in contact with the side walls 212. In this embodiment, the guide portions 211a are integrally formed (integrated) with the bottom wall 211, but they may be constructed separately from the bottom wall 211. The guide portions 211b are integrally formed (integrated) with the bottom wall 211 and the side walls 212, but they may be constructed separately from the bottom wall 211 and the side walls 212.

[0048] Guide portion 211a is positioned between two adjacent energy storage element groups 100a (two adjacent energy storage elements 100 in the Y-axis direction) (see Figure 6, etc.). Guide portion 211b is positioned between the energy storage element group 100a at the Y-axis end (energy storage element 100 at the Y-axis end) and the side wall 212 (see Figure 6, etc.). In other words, the energy storage element group 100a at the Y-axis end (energy storage element 100 at the Y-axis end) is positioned between guide portions 211a and 211b, and the other energy storage element groups 100a (other energy storage elements 100) are positioned between the two guide portions 211a. With this configuration, guide portions 211a and 211b function as guides that lead the energy storage element groups 100a (energy storage elements 100) from the opening 214 to the inside of the outer casing 200 (inside the outer casing body 210).

[0049] The lid 220 is a lid member that closes the opening 214 of the outer casing body 210. The lid 220 is a flat, rectangular member that is parallel to the YZ plane and long in the Y-axis direction, and is larger in size than the opening 214 when viewed from the X-axis direction. The lid 220 is positioned in the positive X-axis direction of the outer casing body 210 and closes the entire opening 214. The lid 220 is in contact with the bottom wall 211 and a pair of side walls 212 of the outer casing body 210, and is joined to the outer casing body 210 by bolts, welding, adhesive, etc., thereby closing the opening 214. As a result, the outer casing 200 becomes a box-shaped member with an opening 201 formed therein.

[0050] [1.3 Description of the manufacturing method of the energy storage device 10] Next, the manufacturing process of the energy storage device 10, specifically the step of housing multiple energy storage elements 100 inside the outer casing 200, will be described. Figures 4 to 6 show the steps of housing multiple energy storage elements 100 inside the outer casing 200 according to this embodiment. Specifically, Figure 4 shows the step of inserting the first energy storage element 101 through the opening 214 of the outer casing body 210. Figure 5 shows the step of inserting the second energy storage element 102 through the opening 214 after housing the first energy storage element 101 in the outer casing body 210. Figure 6 shows the state after all the energy storage elements 100 have been housed in the outer casing body 210.

[0051] The opening 214 of the outer casing body 210 is formed to be large enough for multiple energy storage elements 100 to pass through. By passing multiple energy storage elements 100 through the opening 214, the multiple energy storage elements 100 are inserted into the outer casing body 210 from the opening 214 and placed inside the outer casing 200. Hereinafter, the energy storage element 100 located at the Y-axis positive end of the multiple energy storage elements 100 placed inside the outer casing 200 will be referred to as the first energy storage element 101, and the energy storage element 100 located next to the first energy storage element 101 in the Y-axis negative direction will be referred to as the second energy storage element 102. The group of energy storage elements 100a consisting of multiple (3) first energy storage elements 101 arranged in the X-axis direction will be referred to as the first energy storage element group 101a, and the group of energy storage elements 100a consisting of multiple (3) second energy storage elements 102 arranged in the X-axis direction will be referred to as the second energy storage element group 102a.

[0052] In other words, the multiple energy storage elements 100 have a first energy storage element 101 and a second energy storage element 102 arranged in the Y-axis direction (first direction). The multiple energy storage elements 100 include a first energy storage element group 101a, which is a group of multiple energy storage elements 100 arranged in the X-axis direction (third direction) including the first energy storage element 101. The multiple energy storage elements 100 further include a second energy storage element group 102a, which is a group of multiple energy storage elements 100 arranged in the X-axis direction (third direction) including the second energy storage element 102. The first energy storage element 101 has a shape that is elongated in the X-axis direction (third direction) when viewed from the Z-axis direction (second direction), and has a pair of electrode terminals 150 arranged in the X-axis direction (third direction) when viewed from the Z-axis direction (second direction). The opening 214 is formed to a size that allows the first energy storage element 101 to pass through. The same applies to the second energy storage element 102.

[0053] As shown in Figure 4, in this embodiment, first, the first energy storage element 101 is inserted through the opening 214 of the outer casing body 210. Specifically, the first energy storage element 101 is inserted between the guide portions 211a and 211b from the X-positive direction of the opening 214 and moves toward the X-negative direction, thereby being positioned inside the outer casing body 210. In this way, as shown in Figure 5, all (3) first energy storage elements 101 included in the first energy storage element group 101a are positioned inside the outer casing body 210. Furthermore, as shown in Figure 5, the second energy storage element 102 is inserted between the two guide portions 211a from the X-positive direction of the opening 214 and moves toward the X-negative direction, thereby being positioned inside the outer casing body 210. In this way, as shown in Figure 6, all (3) second energy storage elements 102 included in the second energy storage element group 102a are arranged inside the outer casing body 210, so that all of the energy storage element group 100a (all of the energy storage elements 100) are arranged inside the outer casing body 210.

[0054] In this configuration, with multiple energy storage elements 100 arranged inside the outer casing body 210, the guide portion 211a is positioned between the first energy storage element 101 and the second energy storage element 102. The guide portion 211b is positioned to sandwich the first energy storage element 101 between the guide portion 211a and the guide portion 211b. The guide portions 211a and 211b are positioned to extend in the direction of the alignment of the pair of electrode terminals 150 when viewed from the Z-axis direction (second direction). The guide portions 211a and 211b are positioned to extend in the longitudinal direction of the first energy storage element 101 (and the second energy storage element 102) when viewed from the Z-axis direction (second direction). The guide portions 211a and 211b are positioned to extend from the energy storage element 100 located at one end of the energy storage element group 100a in the X-axis direction (third direction) to the energy storage element 100 located at the other end. In other words, the guide portions 211a and 211b are arranged to extend continuously from the energy storage element 100 at the X-axis negative end to the energy storage element 100 at the X-axis positive end of the energy storage element group 100a.

[0055] Subsequently, as shown in Figure 1, the cover 220 is attached to the outer casing body 210, closing the opening 214. Then, busbars are arranged in the Z-axis positive direction of the multiple energy storage elements 100, and the busbars are connected (joined) to the electrode terminals 150 of the multiple energy storage elements 100.

[0056] [2. Explanation of Effects] As described above, according to the energy storage device 10 of this embodiment, the outer casing 200 has an opening 214 that opens in the X-axis direction (third direction) through which the first energy storage element 101 can pass, and a guide portion 211a that is positioned between the first energy storage element 101 and the second energy storage element 102 which are aligned in the Y-axis direction (first direction) and extends toward the opening 214. In this way, the outer casing 200 is provided with an opening 214 through which the first energy storage element 101 can pass, and a guide portion 211a that extends toward the opening 214 is provided between the first energy storage element 101 and the second energy storage element 102. As a result, the first energy storage element 101 can be easily inserted into the outer casing 200 from the opening 214 by the guide portion 211a, and the first energy storage element 101 can be easily positioned in a position aligned with the second energy storage element 102. Therefore, in the energy storage device 10, the energy storage element 100 (first energy storage element 101) can be easily arranged inside the outer casing 200.

[0057] In the outer casing 200, the guide portion 211a can be easily formed on the outer casing 200 by making it protrude from the bottom wall 211.

[0058] When inserting the energy storage elements 100 from the bottom surface 115 or the electrode terminals 150 side, there is a risk of short-circuiting due to contact between the bottom surfaces 115 and electrode terminals 150 of the two energy storage elements 100. For this reason, the guide portion 211a is positioned to extend in the direction of alignment of the pair of electrode terminals 150 when viewed from the Z-axis direction (second direction). This allows the first energy storage element 101 to be inserted in the direction of alignment of the pair of electrode terminals 150, making it difficult for the bottom surfaces 115 of the first energy storage element 101 and the second energy storage element 102 to contact with the electrode terminals 150. Therefore, it is possible to suppress short-circuiting due to contact between the bottom surfaces 115 and electrode terminals 150 of the two energy storage elements 100.

[0059] By positioning the guide portion 211a so as to extend in the longitudinal direction of the first energy storage element 101 when viewed from the Z-axis direction (second direction), the first energy storage element 101 can be inserted in that longitudinal direction. As a result, the first energy storage element 101 can be easily inserted into the outer casing 200 by gripping one end in that longitudinal direction and inserting it from the other end.

[0060] By positioning the guide portion 211a to extend across the energy storage elements 100 located at both ends of the energy storage element group 100a in the X-axis direction (third direction), the energy storage element group 100a can be easily inserted into the outer casing 200 by the guide portion 211a.

[0061] Even when the first energy storage element 101 is positioned at the Y-axis end of a plurality of energy storage elements 100, a guide portion 211b is provided, and the first energy storage element 101 is guided by the guide portion 211a and the guide portion 211b. This allows the first energy storage element 101 to be easily inserted into the outer casing 200 from the opening 214 of the outer casing 200, thus allowing the first energy storage element 101 to be easily positioned inside the outer casing 200. In particular, by providing the guide portion 211b, it is possible to suppress the first energy storage element 101 from rubbing against the side wall 212 of the outer casing 200 when the first energy storage element 101 is inserted into the outer casing 200, and to prevent heat from accumulating between the first energy storage element 101 and the side wall 212 of the outer casing 200.

[0062] The presence of a cover 220 in the outer casing 200 prevents the energy storage element 100 from protruding from the outer casing 200 after it has been placed inside the outer casing 200, allowing the energy storage element 100 to be stably positioned inside the outer casing 200.

[0063] In the above explanation, the effect of the guide section 211a can be similarly applied to the guide section 211b. Similarly, the effect of the first energy storage element 101 can be similarly applied to other energy storage elements 100, such as the second energy storage element 102.

[0064] [3 Explanation of variations] Although an embodiment of the energy storage device 10 according to the present invention has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed herein are illustrative in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0065] (Variation 1) In the above embodiment, a spacer may be placed to the side of the energy storage element 100. Figure 7 is a perspective view showing the configuration of an energy storage device 11 according to Modification 1 of this embodiment. Specifically, Figure 7 corresponds to Figure 6.

[0066] As shown in Figure 7, the energy storage device 11 in this modified example is equipped with a spacer 300 on the side of the energy storage element 100. The other configurations of this modified example are the same as those of the above embodiment, so a detailed explanation is omitted.

[0067] The spacer 300 is a flat, rectangular member parallel to the XZ plane, positioned alongside the energy storage element 100 in the Y-axis direction, and insulating and / or heat-insulating the energy storage element 100 from other members. The spacer 300 is an insulating or heat-insulating plate positioned in the positive or negative Y-axis direction of the energy storage element 100, and insulating and / or heat-insulating the energy storage elements 100 from each other or from the energy storage element 100 to the casing 200. Specifically, the spacer 300 located at the positive Y-axis end is positioned between the energy storage element 100 located at the positive Y-axis end and the side wall 212 of the casing body 210 in the positive Y-axis direction. The spacer 300 located at the negative Y-axis end is positioned between the energy storage element 100 located at the negative Y-axis end and the side wall 212 of the casing body 210 in the negative Y-axis direction. In other words, the spacer 300 is positioned between the first energy storage element 101 and the second energy storage element 102, and between the first energy storage element 101 and the side wall 212, etc. The spacer 300 can be formed from an insulating material such as any resin material that can be used for the outer casing 200, or from a heat insulating material such as mica.

[0068] In the Z-axis direction (second direction), the spacer 300 is positioned alongside the guide portions 211a and 211b. That is, the spacer 300 is positioned in the Z-axis positive direction of the guide portions 211a and 211b and is supported in contact with the guide portions 211a and 211b. In this modified example, the thickness of the spacer 300 in the Y-axis direction is the same as the thickness of the guide portions 211a and 211b in the Y-axis direction, but it may be a different thickness from that of the guide portions 211a and 211b.

[0069] In this modified example, the spacers 300 are arranged alternately with the energy storage element 100 in the Y-axis direction, but a configuration in which any of the spacers 300 are not arranged is also possible. All spacers 300 may be made of the same material, or any of the spacers 300 may be made of a different material. Multiple spacers 300 arranged in the X-axis direction may be connected (integrated).

[0070] As described above, the energy storage device 11 according to this modified example can achieve the same effects as the above embodiment. In particular, by arranging the guide portions 211a and 211b alongside the spacer 300 in the Z-axis direction, the guide portions 211a and 211b can be utilized as support portions for the spacer 300. In other words, the guide portions 211a and 211b can be arranged by utilizing the space formed by arranging the spacer 300 between the two energy storage elements 100 and between the energy storage elements 100 and the side wall 212. This makes it possible to suppress the increase in the size of the outer casing 200 due to the arrangement of the guide portions 211a and 211b.

[0071] (Other variations) In the above embodiment, the energy storage element 100 is assumed to have a rectangular parallelepiped shape that is flattened in the Y-axis direction (longer in the X-axis direction when viewed from the Z-axis direction), but the size and shape of the energy storage element 100 are not particularly limited. The energy storage element 100 may also have an elongated cylindrical shape, an elliptical prism shape, a polygonal prism shape other than a rectangular parallelepiped, etc., that is flattened in the Y-axis direction (longer in the X-axis direction when viewed from the Z-axis direction). The energy storage element 100 may have a shape that is flattened in a direction tilted from the Y-axis direction, a shape that is flattened in the X-axis direction (longer in the Y-axis direction when viewed from the Z-axis direction), or a shape that is flattened in the Z-axis direction. The energy storage element 100 may not have a flattened shape, but may have a cylindrical shape (cylindrical, cylindrical type) that is circular when viewed from the Z-axis direction, or a rectangular parallelepiped shape that is square when viewed from the Z-axis direction, etc.

[0072] In the above embodiment, the pair of electrode terminals 150 of the energy storage element 100 are arranged side by side in the X-axis direction, but they may also be arranged in a direction tilted from the X-axis direction to the Z-axis direction, or side by side in the Z-axis direction. The pair of electrode terminals 150 may also be arranged in a direction tilted from the X-axis direction to the Y-axis direction, or side by side in the Y-axis direction.

[0073] In the above embodiment, the outer casing body 210 is provided with an opening 201 that opens in the Z-axis positive direction, but it is also possible to have a configuration in which there is no opening 201 (the opening 201 is closed by the upper wall).

[0074] In the above embodiment, the outer casing body 210 integrally has a bottom wall 211 and a pair of side walls 212 and side wall 213, but any of the walls may be made separately. The outer casing body 210 does not have to have any of the pair of side walls 212 and side wall 213. The outer casing 200 does not have to have a lid 220.

[0075] In the above embodiment, the guide portions 211a and 211b of the exterior body 210 are assumed to extend in the X-axis direction toward the opening 214, but they may also extend in a direction inclined from the X-axis direction in the Z-positive or Z-negative direction. The guide portions 211a and 211b may also extend in a direction inclined from the X-axis direction in the Y-positive or Y-negative direction.

[0076] In the above embodiment, the guide portions 211a and 211b extend continuously from one end to the other of the bottom wall 211 in the X-axis direction (from one end to the other of the outer casing 200 or the outer casing body 210), but are not limited to this. The guide portions 211a and 211b may extend intermittently from one end to the other of the bottom wall 211 in the X-axis direction, or they may be located only in a part of the bottom wall 211 from one end to the other in the X-axis direction (such as the central part or the ends). In other words, the guide portions 211a and 211b are not limited to extending across the two energy storage elements 100 located at both ends of the energy storage element group 100a in the X-axis direction.

[0077] In the above embodiment, the guide portions 211a and 211b extend in the direction of alignment of the pair of electrode terminals 150 when viewed from the Z-axis direction, but they may also extend in a direction inclined from the said alignment direction or in a direction perpendicular to the said alignment direction when viewed from the Z-axis direction. The guide portions 211a and 211b extend in the longitudinal direction of the energy storage element 100 when viewed from the Z-axis direction, but they may also extend in a direction inclined from the said longitudinal direction or in a direction perpendicular to the said longitudinal direction when viewed from the Z-axis direction.

[0078] In the above embodiment, the guide portions 211a and 211b are convex portions that protrude in the Z-axis direction from the bottom wall 211 of the outer casing body 210, but they may also be elongated members that are spaced apart from the bottom wall 211.

[0079] In the above embodiment, the opening 214 of the outer casing body 210 is assumed to be large enough for all of the energy storage elements 100 to pass through, but it is sufficient if it is large enough for at least one of the energy storage elements 100 to pass through. In other words, the opening 214 does not have to be an opening that covers the entire surface of the outer casing body 210 in the X-axis positive direction, but rather an opening that covers only a part of the surface of the outer casing body 210 in the X-axis positive direction. That is, the outer casing body 210 also has a side wall in the X-axis positive direction, and the opening 214 may be an opening formed in that side wall that is large enough for at least one of the energy storage elements 100 to pass through.

[0080] In the above embodiment, the multiple energy storage elements 100 are inserted into the main body 210 of the casing and then connected with busbars. However, the multiple energy storage elements 100 may be inserted into the main body 210 with the busbars already connected. In this case, the electrode terminals 150 of the energy storage elements 100 do not need to protrude toward the opening 201.

[0081] In the above embodiment, the openings 201 and 214 of the exterior body 210 are connected, but a partition may be provided between the openings 201 and 214.

[0082] In the above embodiment, it is not necessary to provide any of the guide portions 211a. It is also not necessary to provide any or both of the two guide portions 211b.

[0083] In the above embodiment, multiple energy storage elements 100 included in the energy storage element group 100a may be restrained by a restraining member (end plate, side plate, etc.). In other words, the energy storage element group 100a integrated by the restraining member may be inserted into the outer casing body 210. The energy storage element group 100a may have only one energy storage element 100.

[0084] The present invention also includes forms constructed by arbitrarily combining the components of the above embodiments and their modifications. [Industrial applicability]

[0085] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of Symbols]

[0086] 10, 11 Energy storage devices 100 energy storage elements 100A Energy Storage Element Group 101 First energy storage element 101a First energy storage element group 102 Second energy storage element 102a Second group of energy storage elements 110 Container 111, 112 long side 113, 114 short side 115 Base 116 Terminal placement surface 120 Container body 130 Container lid 150 Electrode terminal 160 Electrode body 170 Current collector 200 Exterior 201, 214 openings 210 Main body of the exterior 211 Bottom wall 211a, 211b Guide section 212, 213 side wall 220 Lid 300 Spacer

Claims

1. An energy storage device comprising a plurality of energy storage elements and an outer casing that houses the plurality of energy storage elements, The plurality of energy storage elements include a first energy storage element and a second energy storage element arranged in a first direction. The exterior body is, In the first direction, the side wall facing the plurality of energy storage elements, In a second direction perpendicular to the first direction, the bottom wall facing the plurality of energy storage elements, An opening that opens toward a third direction perpendicular to the first direction and the second direction, the opening through which the first energy storage element can pass, It has a guide portion positioned between the first energy storage element and the second energy storage element and extending toward the opening, The first energy storage element comprises an electrode body, a rectangular container housing the electrode body, and a pair of electrode terminals arranged in the container and aligned in the third direction when viewed from the second direction. The guide portion extends in the direction of the alignment of the pair of electrode terminals when viewed from the second direction. Energy storage device.

2. The guide portion is a protrusion that extends from the bottom wall in the second direction. The energy storage device according to claim 1.

3. The first energy storage element has a shape that is elongated in the third direction when viewed from the second direction, The guide portion extends in the longitudinal direction of the first energy storage element when viewed from the second direction. The energy storage device according to claim 1 or 2.

4. The plurality of energy storage elements include a group of energy storage elements consisting of a plurality of energy storage elements arranged in the third direction, including the first energy storage element. The guide portion extends from the energy storage element located at one end of the energy storage element group in the third direction to the energy storage element located at the other end. The energy storage device according to any one of claims 1 to 3.

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