Energy storage element

Abstract

To provide a power storage element that can reduce the size or increase the capacity.SOLUTION: A power storage element 10 includes a first electrode body 600 and a second electrode body 700 and includes one or more first sheet members 810 disposed on an outer surface of the first electrode body 600 and at a position including the place between the first electrode body 600 and the second electrode body 700, and one or more second sheet members 820 disposed on an outer surface of the second electrode body 700 and at the position including the place between the first electrode body 600 and the second electrode body 700 or one or more third sheet members 830 disposed on the outer surface of the first electrode body 600 and the second electrode body 700 across the first electrode body 600 and the second electrode body 700. At least one first sheet member 810 is disposed at a position that does not overlap with all the second sheet members 820 between the first electrode body 600 and the second electrode body 700 or at a position that does not overlap with all the third sheet members 830 on the surface of the first electrode body 600 opposite to the second electrode body 700.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an energy storage element including an electrode body having a sheet member disposed on the outer surface thereof. [Background technology]

[0002] Conventionally, in an energy storage element including an electrode body, a configuration in which a sheet member is arranged on the outer surface of the electrode body is known. For example, Patent Document 1 discloses a configuration in which an electrode stack (electrode body) used in an energy storage element has a substantially rectangular parallelepiped shape in which a plurality of electrodes are stacked, and is fixed from the top surface to the bottom surface by a fixing member (sheet member) along the stacking direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-80324 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described conventional energy storage elements, it may be impossible to achieve miniaturization or high capacity. That is, when an energy storage element includes multiple electrode bodies and multiple sheet members are arranged for the multiple electrode bodies, the size of the electrode body including the sheet members increases due to the multiple sheet members overlapping, which may result in an increase in the size of the energy storage element or a decrease in capacity. In such cases, it is impossible to achieve miniaturization or high capacity of the energy storage element.

[0005] The present invention was made by the inventors of the present application by focusing on the above-mentioned problems, and has an object to provide an energy storage element that can be made smaller and has a higher capacity. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one embodiment of the present invention provides an energy storage element comprising a first electrode body and a second electrode body, and comprising one or more first sheet members arranged on the outer surface of the first electrode body and at a position including the gap between the first electrode body and the second electrode body, and one or more second sheet members arranged on the outer surface of the second electrode body and at a position including the gap between the first electrode body and the second electrode body, or one or more third sheet members arranged on the outer surfaces of the first electrode body and the second electrode body across the first electrode body and the second electrode body, wherein at least one of the first sheet members is arranged in a position between the first electrode body and the second electrode body so as not to overlap with any of the second sheet members, or in a position on the side of the first electrode body opposite the second electrode body so as not to overlap with any of the third sheet members.

[0007] According to this, in the energy storage element, at least one first sheet member is disposed on the outer surface of the first electrode body, between the first electrode body and the second electrode body, in a position where it does not overlap with any of the second sheet members, or on the surface of the first electrode body opposite the second electrode body, in a position where it does not overlap with any of the third sheet members. In this way, when a first sheet member and a second sheet member or a third sheet member are disposed on the outer surface of one or both of the first electrode body and the second electrode body, at least one first sheet member is disposed in a position where it does not overlap with any of the second sheet members or any of the third sheet members. This prevents overlap between the first sheet member and the second sheet member or the third sheet member. Therefore, the size of the electrode body, including the sheet members, can be prevented from increasing, allowing for a smaller energy storage element and a higher capacity.

[0008] The energy storage element may include one or more second sheet members, and all of the first sheet members may be positioned between the first electrode body and the second electrode body so as not to overlap any of the second sheet members.

[0009] According to this, in a configuration in which the energy storage element includes the second sheet member, by arranging all of the first sheet members in positions where they do not overlap with all of the second sheet members, it is possible to further reduce overlap between the first sheet members and the second sheet members, thereby further reducing the size of the electrode body including the sheet members, and achieving a smaller size or higher capacity of the energy storage element.

[0010] The energy storage element may include one or more third sheet members, and all of the first sheet members may be arranged on the side of the first electrode body opposite the second electrode body in a position where they do not overlap with any of the third sheet members.

[0011] According to this, in a configuration in which the energy storage element includes a third sheet member, by arranging all of the first sheet members in positions where they do not overlap with any of the third sheet members, it is possible to further reduce overlap between the first sheet members and the third sheet members, thereby further reducing the size of the electrode body including the sheet members, and achieving a smaller size or higher capacity of the energy storage element.

[0012] The energy storage element may include one or more second sheet members and one or more third sheet members, and at least one of the second sheet members may be positioned on the surface of the second electrode body opposite the first electrode body in a position that does not overlap with any of the third sheet members.

[0013] According to this, in a configuration in which the energy storage element includes second and third sheet members, by arranging at least one second sheet member in a position where it does not overlap with any of the third sheet members, it is possible to prevent the second and third sheet members from overlapping with each other, thereby preventing the electrode body including the sheet members from becoming larger, and enabling the energy storage element to be made smaller or have a higher capacity.

[0014] All of the second sheet members may be arranged on a surface of the second electrode body opposite to the first electrode body at positions where they do not overlap with any of the third sheet members.

[0015] This arrangement further reduces overlapping between the second sheet members and the third sheet members by arranging all of the second sheet members at positions where they do not overlap with any of the third sheet members, thereby further reducing the size of the electrode assembly including the sheet members, and enabling the energy storage element to be made smaller or have a higher capacity.

[0016] The energy storage element may include one or more third sheet members, and at least one of the third sheet members may be arranged on a side of the first electrode body and the second electrode body that is different from all of the first sheet members.

[0017] According to this, in a configuration in which the energy storage element includes a third sheet member, by arranging the third sheet member on a side different from all of the first sheet members, it is easy to arrange the third sheet member in a position where it does not overlap with all of the first sheet members, thereby easily realizing a configuration that aims to reduce the size or increase the capacity of the energy storage element.

[0018] The present invention can be realized not only as such a storage element, but also as a combination of a first electrode body and a second electrode body, a first sheet member, and a second or third sheet member. [Effects of the Invention]

[0019] According to the energy storage device of the present invention, it is possible to achieve a reduction in size or a high capacity. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view showing the appearance of an energy storage element according to an embodiment; [Figure 2] FIG. 2 is an exploded perspective view showing the components of the energy storage device according to the embodiment. [Figure 3] FIG. 2 is a perspective view showing the configuration of a first electrode body and a second electrode body according to the embodiment. [Figure 4]1 is a perspective view showing a configuration in which a first sheet member and a second sheet member are arranged on a first electrode body and a second electrode body according to an embodiment. FIG. [Figure 5] 1 is a front view showing a configuration in which a first sheet member and a second sheet member are arranged on a first electrode body and a second electrode body according to an embodiment. FIG. [Figure 6] FIG. 10 is a perspective view showing a configuration in which a third sheet member is disposed on a first electrode body and a second electrode body in the embodiment. [Figure 7] 1A to 1C are a top view, a front view, and a bottom view showing a configuration in which a first electrode body on which a first sheet member is arranged and a second electrode body on which a second sheet member is arranged are stacked in accordance with an embodiment of the present invention. [Figure 8] 10A to 10C are a top view, a front view, and a bottom view showing a configuration in which a third sheet member is arranged on a first electrode body and a second electrode body in the embodiment. [Figure 9A] FIG. 10 is a perspective view showing a configuration in which a second sheet member is not disposed on a first electrode body and a second electrode body according to a modified example of the embodiment. [Figure 9B] FIG. 10 is a perspective view showing a configuration in which a second sheet member is not disposed on a first electrode body and a second electrode body according to another modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, with reference to the drawings, an energy storage element according to an embodiment of the present invention (including its modified examples) will be described. The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, 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. In each drawing, dimensions and the like are not strictly illustrated. In each drawing, the same or similar components are designated by the same reference numerals.

[0022] In the following description and drawings, the X-axis direction refers to the arrangement direction of a pair of electrode terminals (positive and negative, hereinafter) of the energy storage element, the arrangement direction of a pair of current collectors, the width direction of the first and second electrode bodies, or the direction in which the short sides of the container face each other. The Y-axis direction refers to the arrangement direction of the first and second electrode bodies, the stacking direction of the electrode plates of the first and second electrode bodies, the thickness direction of the first and second electrode bodies, the direction in which the long sides of the container face each other, or the thickness direction of the container. The Z-axis direction refers to the direction in which the winding axis of the first and second electrode bodies extends, the height direction of the first and second electrode bodies, the arrangement direction of the electrode terminals, current collectors, and first and second electrode bodies, the arrangement direction of the container body and lid of the container, or the up-down direction. The X-axis, Y-axis, and Z-axis directions intersect each other (orthogonal in this embodiment). Depending on the mode of use, the Z-axis direction may not be the up-down direction, but for the sake of convenience, the following description will be given assuming that the Z-axis direction is the up-down direction.

[0023] In the following description, for example, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the opposite direction to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. Furthermore, expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the directions or attitudes are not strictly those of the same kind. For example, saying that two directions are perpendicular does not only mean that the two directions are completely perpendicular, but also means that the directions are substantially perpendicular, i.e., there is a difference of, for example, a few percent.

[0024] (Embodiment) [1 General Description of Energy Storage Element 10] First, an overall description will be given of an energy storage device 10 according to the present embodiment. Fig. 1 is a perspective view showing the appearance of an energy storage device 10 according to the present embodiment. Fig. 2 is an exploded perspective view showing each component of the energy storage device 10 according to the present embodiment.

[0025] The energy storage device 10 is a secondary battery (single cell) that can charge and discharge electricity, specifically a nonaqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage device 10 is used for power storage or power supply purposes. The energy storage device 10 is used, for example, as a battery for driving or starting the engine of a mobile object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline-powered automobile. Examples of the electric railway vehicle include a train, a monorail, a linear motor car, and a hybrid train equipped with both a diesel engine and an electric motor. The energy storage device 10 can also be used as a stationary battery for home or business use.

[0026] The energy storage element 10 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 may be a capacitor. The energy storage element 10 may not be a secondary battery, but may be a primary battery that allows stored electricity to be used without the user having to charge it. The energy storage element 10 may be a battery that uses a solid electrolyte. The energy storage element 10 may also be a pouch-type energy storage element. In this embodiment, the energy storage element 10 is illustrated as having a flat rectangular parallelepiped (square) shape, but the shape of the energy storage element 10 is not limited to a rectangular parallelepiped shape, and may be a cylindrical shape, an elongated cylindrical shape, a polygonal prism shape other than a rectangular parallelepiped, or the like.

[0027] As shown in FIG. 1, the energy storage device 10 includes a container 100, a pair of electrode terminals 200 (positive and negative), and a pair of upper gaskets 300 (positive and negative). As shown in FIG. 2, the container 100 contains a pair of lower gaskets 400 (positive and negative), a pair of current collectors 500 (positive and negative), a first electrode assembly 600, a second electrode assembly 700, a first sheet member 810, a second sheet member 820, and a third sheet member 830. An electrolyte (non-aqueous electrolyte) is sealed inside the container 100, but is not shown in the figure. There are no particular limitations on the type of electrolyte, and various electrolytes can be selected as long as they do not impair the performance of the energy storage device 10. In addition to the above components, spacers may be placed on the sides or below the first electrode body 600 and the second electrode body 700, and insulating films may be placed to wrap around the first electrode body 600 and the second electrode body 700, etc.

[0028] The container 100 is a rectangular parallelepiped (square or box-shaped) case having a container body 110 with an opening formed therein and a lid 120 that closes the opening of the container body 110. The container body 110 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 100. The container body 110 has a pair of flat, rectangular long side walls 111 on both side surfaces (long side surfaces) in the Y-axis direction, a pair of flat, rectangular short side walls 112 on both side surfaces (short side surfaces) in the X-axis direction, and a flat, rectangular bottom wall 113 on the negative Z-axis side. The lid 120 is a rectangular plate-like member that constitutes the lid of the container 100 and is disposed so as to extend in the X-axis direction in the positive Z-axis direction of the container body 110. The lid 120 is provided with a gas exhaust valve 121 for releasing the pressure inside the container 100 if the pressure inside the container 100 rises excessively, and a liquid injection part 122 for injecting the electrolyte into the container 100.

[0029] With this configuration, the container 100 is structured so that the inside is sealed by accommodating the first electrode body 600, the second electrode body 700, etc. inside the container body 110, and then joining the container body 110 and the lid body 120 by welding or the like. The material of the container 100 (container body 110 and lid body 120) is not particularly limited, and can be a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin can also be used.

[0030] The first electrode body 600 and the second electrode body 700 are each power storage elements (power generation elements) that include a positive electrode plate, a negative electrode plate, and a separator and can store electricity. Specifically, the first electrode body 600 and the second electrode body 700 are each so-called horizontally wound electrode bodies that are oval when viewed from the Z-axis direction and are formed by winding layers of positive electrode plates, negative electrode plates, and separators sandwiched between them. In this way, the first electrode body 600 and the second electrode body 700 have the same configuration.

[0031] Specifically, in the first electrode assembly 600, multiple tabs of the positive electrode plates are stacked to form a positive electrode side tab bundle 620, and multiple tabs of the negative electrode plates are stacked to form a negative electrode side tab bundle 630. That is, the first electrode assembly 600 has an electrode assembly main body 610 and tab bundles 620 and 630 that protrude in the positive direction of the Z axis from a portion of the electrode assembly main body 610. Similarly, in the second electrode assembly 700, multiple tabs of the positive electrode plates are stacked to form a positive electrode side tab bundle 720, and multiple tabs of the negative electrode plates are stacked to form a negative electrode side tab bundle 730. That is, the second electrode assembly 700 has an electrode assembly main body 710 and tab bundles 720 and 730 that protrude in the positive direction of the Z axis from a portion of the electrode assembly main body 710. A detailed description of the configurations of the first electrode assembly 600 and the second electrode assembly 700 will be given later.

[0032] The first sheet member 810, the second sheet member 820, and the third sheet member 830 are sheet-like members disposed on the outer surface of at least one of the first electrode body 600 and the second electrode body 700. In this embodiment, the first sheet member 810 is an insulating tape disposed (attached) on the outer surface of the first electrode body 600, and sandwiches and fixes (binds) the positive electrode plate, the negative electrode plate, and the separator of the first electrode body 600 in the Y-axis direction. The second sheet member 820 is an insulating tape disposed (attached) on the outer surface of the second electrode body 700, and sandwiches and fixes (binds) the positive electrode plate, the negative electrode plate, and the separator of the second electrode body 700 in the Y-axis direction. The third sheet member 830 is an insulating tape disposed (attached) on the outer surfaces of both the first electrode body 600 and the second electrode body 700, and sandwiches and fixes (binds) the first electrode body 600 and the second electrode body 700 in the Y-axis direction.

[0033] The first sheet member 810, the second sheet member 820, and the third sheet member 830 are formed of an electrically insulating resin, such as polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), ABS resin, or a composite material thereof. The first sheet member 810, the second sheet member 820, and the third sheet member 830 may be formed of any material, and may be formed of, for example, a conductive material as long as the electrical insulation of the first electrode body 600 and the second electrode body 700 is ensured. A detailed description of the configurations of the first sheet member 810, the second sheet member 820, and the third sheet member 830 will be given later.

[0034] The electrode terminals 200 are terminal members (positive electrode terminal and negative electrode terminal) electrically connected to the first electrode body 600 and the second electrode body 700 via the current collector 500. In other words, the electrode terminals 200 are metal members that lead out electricity stored in the first electrode body 600 and the second electrode body 700 to the external space of the energy storage element 10 and introduce electricity into the internal space of the energy storage element 10 to store electricity in the first electrode body 600 and the second electrode body 700. The electrode terminals 200 are formed of a conductive member such as a metal, such as aluminum, an aluminum alloy, copper, or a copper alloy. The electrode terminals 200 are connected (joined) to the current collector 500 by crimping or the like, and are attached to the lid 120.

[0035] Specifically, the electrode terminal 200 has a shaft portion 201 (rivet portion) extending downward (in the negative Z-axis direction). The shaft portion 201 is inserted into the through-hole 301 of the upper gasket 300, the through-hole 123 of the lid 120, the through-hole 401 of the lower gasket 400, and the through-hole 501 of the current collector 500, and is crimped. As a result, the electrode terminal 200, together with the upper gasket 300, the lower gasket 400, and the current collector 500, is fixed to the lid 120. Note that the method for connecting (joining) the electrode terminal 200 and the current collector 500 is not limited to crimping, and welding such as ultrasonic welding, laser welding, or resistance welding, or mechanical joining other than crimping, such as screw fastening, may also be used.

[0036] The current collectors 500 are flat, rectangular current collecting members (positive electrode current collector and negative electrode current collector) that electrically connect the first electrode body 600 and the second electrode body 700 to the electrode terminal 200. Specifically, the positive electrode side current collector 500 is connected (joined) to the positive electrode side tab bundles 620 and 720 of the first electrode body 600 and the second electrode body 700 by welding or the like, and is also joined to the positive electrode side electrode terminal 200 by crimping or the like, as described above. The negative electrode side current collector 500 is connected (joined) to the negative electrode side tab bundles 630 and 730 of the first electrode body 600 and the second electrode body 700 by welding or the like, and is also joined to the negative electrode side electrode terminal 200 by crimping or the like, as described above. The material of the current collector 500 is not particularly limited, but for example, the positive electrode side current collector 500 is formed of a conductive material such as a metal such as aluminum or an aluminum alloy, and the negative electrode side current collector 500 is formed of a conductive material such as a metal such as copper or a copper alloy. Note that the method for connecting (joining) the current collector 500 and the tab bundles 620 and 720 or the tab bundles 630 and 730 may be any welding method such as ultrasonic welding, laser welding, or resistance welding, or may be mechanical joining such as crimping or screw fastening.

[0037] The upper gasket 300 is a flat, electrically insulating sealing member disposed between the lid 120 of the container 100 and the electrode terminal 200. The lower gasket 400 is a flat, electrically insulating sealing member disposed between the lid 120 and the current collector 500. The upper gasket 300 and the lower gasket 400 are formed, for example, from any electrically insulating resin that can be used for the first sheet member 810, etc.

[0038] [2. Description of the Configuration of the First Electrode Body 600 and the Second Electrode Body 700] Next, the configurations of the first electrode body 600 and the second electrode body 700 will be described in detail. Fig. 3 is a perspective view showing the configurations of the first electrode body 600 and the second electrode body 700 according to this embodiment. Since the first electrode body 600 and the second electrode body 700 have the same configuration, Fig. 3 shows the configurations of the first electrode body 600 and the second electrode body 700 using the same diagram. Specifically, Fig. 3(a) shows the configuration of the first electrode body 600 (or the second electrode body 700) in a partially unfolded wound state, and Fig. 3(b) shows the configuration of the first electrode body 600 (or the second electrode body 700) after winding.

[0039] As described above, the first electrode body 600 and the second electrode body 700 have the same configuration, and therefore, hereinafter, the configuration of the first electrode body 600 will be mainly described, and the description of the configuration of the second electrode body 700 will be simplified or omitted. As shown in Fig. 3(a), the first electrode body 600 is formed by alternately stacking and winding a positive electrode plate 640, a negative electrode plate 650, and separators 661 and 662. In other words, the first electrode body 600 is formed by stacking and winding a positive electrode plate 640, a separator 661, a negative electrode plate 650, and a separator 662 in this order.

[0040] The positive electrode plate 640 is an electrode plate in which a positive electrode active material layer is formed on the surface of a positive electrode substrate layer, which is a long strip of metal foil made of aluminum or an aluminum alloy. The negative electrode plate 650 is an electrode plate in which a negative electrode active material layer is formed on the surface of a negative electrode substrate layer, which is a long strip of metal foil made of copper or a copper alloy. For the positive electrode substrate layer and the negative electrode substrate layer, any known material can be used as long as it is stable against oxidation-reduction reactions during charge and discharge, such as nickel, iron, stainless steel, titanium, baked carbon, conductive polymers, conductive glass, and Al-Cd alloys. 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 can be any known material as long as it is capable of absorbing and releasing lithium ions.

[0041] For example, the positive electrode active material may be a polyanion compound such as LiMPO4, LiMSiO4, or LiMBO3 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), lithium titanate, LiMn2O4, or LiMn 1.5 Ni 0.5 Examples of the anode active material include spinel-type lithium manganese oxides such as LiTiO4, and lithium transition metal oxides such as LiMO2 (wherein M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.). Examples of the anode active material include lithium metal, lithium alloys (lithium-metal-containing alloys such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and Wood's alloy), alloys capable of absorbing and releasing lithium, carbon materials (e.g., graphite, non-graphitizable carbon, easily graphitizable carbon, low-temperature fired carbon, amorphous carbon, etc.), silicon oxides, metal oxides, and lithium metal oxides (Li4Ti5O 12 and the like), polyphosphate compounds, or compounds of transition metals and elements of Groups 14 to 16, such as Co3O4 and Fe2P, which are generally called conversion negative electrodes.

[0042] Separators 661 and 662 are microporous sheets made of resin. Any known material can be used as the material for separators 661 and 662 as long as it does not impair the performance of energy storage element 10. For example, separators 661 and 662 can be made of woven fabric or nonwoven fabric that is insoluble in organic solvents, or a synthetic resin microporous film made of a polyolefin resin such as polyethylene.

[0043] The positive electrode plate 640 has, at its end in the positive Z-axis direction, a plurality of rectangular tabs 641 protruding in the positive Z-axis direction, and the plurality of tabs 641 are arranged in a stacked state in the Y-axis direction. Similarly, the negative electrode plate 650 has, at its end in the positive Z-axis direction, a plurality of rectangular tabs 651 protruding in the positive Z-axis direction, and the plurality of tabs 651 are arranged in a stacked state in the Y-axis direction. The tabs 641 and 651 are portions where no active material layer is formed and the base material layer is exposed. The shapes of the tabs 641 and 651 are not particularly limited.

[0044] 3(b), the stacked tabs 641 are bundled together to form tab bundle 620, which extends and protrudes in the positive direction of the Z axis. Similarly, the stacked tabs 651 are bundled together to form tab bundle 630, which extends and protrudes in the positive direction of the Z axis. These tab bundles 620 and 630 are joined to the surfaces of current collector 500 facing each other in the Y axis direction on the positive side of the Y axis, and then bent together with current collector 500 in the positive direction of the Y axis.

[0045] The electrode body main body 610 is a portion that constitutes the main body of the first electrode body 600, and specifically, is the portion of the first electrode body 600 other than the tab bundles 620 and 630. In other words, the electrode body main body 610 is an elongated columnar or cylindrical portion formed by winding together the portions of the positive electrode plate 640 and the negative electrode plate 650 on which the active material layers are formed and the separators 661 and 662. As a result, the electrode body main body 610 has a pair of electrode body flat portions 611 and 612 on both sides in the Y-axis direction, and a pair of electrode body curved portions 613 and 614 on both sides in the X-axis direction.

[0046] The electrode body flat portion 611 is a flat, rectangular portion extending parallel to the XZ plane oriented in the negative Y-axis direction, connecting the pair of electrode body curved portions 613 and 614, and is disposed opposite the long side wall portion 111 of the container body 110 in the negative Y-axis direction. The electrode body flat portion 612 is a flat, rectangular portion extending parallel to the XZ plane oriented in the positive Y-axis direction, connecting the pair of electrode body curved portions 613 and 614, and is disposed opposite the second electrode body 700. The electrode body curved portion 613 is a curved portion that is curved in a semicircular arc shape so as to protrude in the negative X-axis direction when viewed from the Z-axis direction, and is extended in the Z-axis direction, and is disposed opposite the short side wall portion 112 of the container body 110 in the negative X-axis direction. The electrode body curved portion 614 is a curved portion that is curved in a semicircular arc shape so as to protrude in the positive X-axis direction when viewed from the Z-axis direction, and extends in the Z-axis direction, and is positioned opposite the short side wall portion 112 of the container body 110 in the positive X-axis direction.

[0047] Similarly, the second electrode body 700 has a positive electrode plate 740, a negative electrode plate 750, and separators 761 and 762, with the positive electrode plate 740 having a tab 741 and the negative electrode plate 750 having a tab 751. A plurality of tabs 741 are bundled together to form a tab bundle 720, and a plurality of tabs 751 are bundled together to form a tab bundle 730. The electrode body main body 710 of the second electrode body 700 has a pair of electrode body flat portions 711 and 712 on both sides in the Y-axis direction, and a pair of electrode body curved portions 713 and 714 on both sides in the X-axis direction.

[0048] [3. Description of the First Sheet Member 810, the Second Sheet Member 820, and the Third Sheet Member 830] Next, the configurations of the first sheet member 810, the second sheet member 820, and the third sheet member 830 will be described in detail. FIG. 4 is a perspective view showing a configuration in which the first sheet member 810 and the second sheet member 820 are arranged on the first electrode body 600 and the second electrode body 700 according to the present embodiment. Specifically, FIG. 4(a) is a perspective view showing a configuration in which the first sheet member 810 is arranged on the first electrode body 600, and FIG. 4(b) is a perspective view showing a configuration in which the second sheet member 820 is arranged on the second electrode body 700. FIG. 5 is a front view showing a configuration in which the first sheet member 810 and the second sheet member 820 are arranged on the first electrode body 600 and the second electrode body 700 according to the present embodiment. Specifically, FIG. 5(a) is a front view showing a configuration in which the first sheet member 810 is arranged on the first electrode body 600, and FIG. 5(b) is a front view showing a configuration in which the second sheet member 820 is arranged on the second electrode body 700.

[0049] FIG. 6 is a perspective view showing a configuration in which a third sheet member 830 is arranged on the first electrode body 600 and the second electrode body 700 according to the present embodiment. Specifically, FIG. 6(a) is a perspective view showing a configuration in which the first electrode body 600 on which the first sheet member 810 is arranged and the second electrode body 700 on which the second sheet member 820 is arranged are stacked. FIG. 6(b) is a perspective view showing a configuration in which the third sheet member 830 is arranged on the first electrode body 600 and the second electrode body 700 shown in FIG. 6(a). FIG. 7 is a top view, a front view, and a bottom view showing a configuration in which the first electrode body 600 on which the first sheet member 810 according to the present embodiment is arranged and the second electrode body 700 on which the second sheet member 820 is arranged are stacked. Specifically, FIG. 7 shows a top view, a front view, and a bottom view of the configuration shown in FIG. 6(a), where FIG. 7(a) is a top view, FIG. 7(b) is a front view, and FIG. 7(c) is a bottom view. Fig. 8 is a top view, a front view, and a bottom view showing a configuration in which a third sheet member 830 is arranged on the first electrode body 600 and the second electrode body 700 according to this embodiment. Specifically, Fig. 8 shows a top view, a front view, and a bottom view of the configuration shown in Fig. 6(b), with Fig. 8(a) being the top view, Fig. 8(b) being the front view, and Fig. 8(c) being the bottom view.

[0050] [3.1 Description of the configuration of the first sheet member 810] 4(a) and 5(a), one or more first sheet members 810 are arranged on the outer surface of the first electrode body 600 and at a position including between the first electrode body 600 and the second electrode body 700. Specifically, a plurality of first sheet members 810 are arranged on the outer surface of the first electrode body 600 on the side opposite to the second electrode body 700 (the surface in the negative Y-axis direction), the surface in the Z-axis direction, and between the first electrode body 600 and the second electrode body 700 (the surface in the positive Y-axis direction). In this embodiment, three first sheet members 810 (811 to 813) are arranged at the end of the electrode body main body 610 of the first electrode body 600 in the positive Z-axis direction, and three first sheet members 810 (814 to 816) are arranged at the end of the electrode body main body 610 in the negative Z-axis direction. More specifically, the six first sheet members 810 (811 to 816) are attached to the electrode body flat portions 611 and 612 of the electrode body main body portion 610 so as to sandwich the electrode body flat portions 611 and 612 in the Y-axis direction.

[0051] These six first sheet members 810 (811 to 816) secure (bind) the positive electrode plate 640, negative electrode plate 650, and separators 661 and 662 of the first electrode body 600 in a stacked state in the Y-axis direction. Each first sheet member 810 is arranged on both sides of the first electrode body 600 in the Y-axis direction and on the surface in the Z-axis direction, thereby sandwiching and securing the first electrode body 600 in the Y-axis direction, thereby more reliably securing the positive electrode plate 640, negative electrode plate 650, and separators 661 and 662.

[0052] The first sheet member 811 is disposed (attached) between the tab bundles 620 and 630 of the first electrode assembly 600 and at a position close to the tab bundle 630. The first sheet member 811 is disposed from the surface of the first electrode assembly 600 in the negative Y-axis direction (the surface opposite the second electrode assembly 700), across the surface of the first electrode assembly 600 in the positive Z-axis direction, to the surface of the first electrode assembly 600 in the positive Y-axis direction (the surface on the second electrode assembly 700 side). In other words, the first sheet member 811 is disposed in an attached state from the outer surface of the electrode assembly flat portion 611 to the outer surface of the electrode assembly flat portion 612 at the ends of the electrode assembly flat portions 611 and 612 in the positive Z-axis direction and at the center in the X-axis direction.

[0053] The first sheet member 812 is arranged (attached) at a position close to the tab bundle 620 of the first electrode assembly 600 in the negative X-axis direction of the tab bundle 620. Like the first sheet member 811, the first sheet member 812 is arranged from the surface of the first electrode assembly 600 in the negative Y-axis direction, passing through the surface in the positive Z-axis direction, to the surface in the positive Y-axis direction. In other words, the first sheet member 812 is arranged in an attached state, extending from the outer surface of the electrode assembly flat portion 611 to the outer surface of the electrode assembly flat portion 612, at the ends of the electrode assembly flat portions 611 and 612 in the positive Z-axis direction and the negative X-axis direction. The first sheet member 812 has a smaller width than the first sheet member 811 in the X-axis direction, and a length equivalent to that of the first sheet member 811 in the Z-axis direction.

[0054] The first sheet member 813 is disposed (attached) at a position close to the tab bundle 630 of the first electrode assembly 600 in the positive X-axis direction of the tab bundle 630. Like the first sheet member 811, the first sheet member 813 is also disposed from the surface of the first electrode assembly 600 in the negative Y-axis direction, passing through the surface in the positive Z-axis direction, to the surface in the positive Y-axis direction. That is, the first sheet member 813 is disposed in an attached state from the outer surface of the electrode assembly flat portion 611 to the outer surface of the electrode assembly flat portion 612 at the ends of the electrode assembly flat portions 611 and 612 in the positive Z-axis direction and the positive X-axis direction. The first sheet member 813 has a smaller width than the first sheet member 811 in the X-axis direction and the same width as the first sheet member 812, and a length in the Z-axis direction that is the same as the first sheet members 811 and 812.

[0055] The first sheet members 814 to 816 are respectively arranged (attached) at positions facing the first sheet members 811 to 813 in the Z-axis direction. The first sheet members 814 to 816 are arranged from the surface of the first electrode body 600 in the negative Y-axis direction (the surface opposite the second electrode body 700), across the surface of the first electrode body 600 in the negative Z-axis direction, to the surface of the first electrode body 600 in the positive Y-axis direction (the surface on the second electrode body 700 side). In other words, the first sheet members 814 to 816 are arranged in an attached state from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 612 at the ends of the electrode body flat portions 611 and 612 in the negative Z-axis direction and at the center and both ends in the X-axis direction. In this embodiment, the first sheet members 814 to 816 have a configuration obtained by rotating the first sheet members 811 to 813 by 180° around the Y-axis. In other words, the first sheet members 815 and 816 have the same width in the X-axis direction, are narrower than the first sheet member 814, and have the same length in the Z-axis direction as the first sheet member 814.

[0056] [3.2 Explanation of the configuration of the second sheet member 820 and its positional relationship with the first sheet member 810] 4(b) and 5(b), one or more second sheet members 820 are arranged on the outer surface of the second electrode body 700 and at a position including the space between the first electrode body 600 and the second electrode body 700. Specifically, a plurality of second sheet members 820 are arranged on the outer surface of the second electrode body 700 between the first electrode body 600 and the second electrode body 700 (the surface in the negative Y-axis direction), on the surface in the Z-axis direction, and on the surface opposite to the first electrode body 600 (the surface in the positive Y-axis direction). In this embodiment, three second sheet members 820 (821 to 823) are arranged on the end of the electrode body main body 710 of the second electrode body 700 in the positive Z-axis direction, and three second sheet members 820 (824 to 826) are arranged on the end of the electrode body main body 710 in the negative Z-axis direction. More specifically, the six second sheet members 820 (821 to 826) are attached to the electrode body flat portions 711 and 712 of the electrode body main body portion 710 so as to sandwich the electrode body flat portions 711 and 712 in the Y-axis direction.

[0057] These six second sheet members 820 (821 to 826) secure (bind) the positive electrode plate 740, negative electrode plate 750, and separators 761 and 762 of the second electrode body 700 in a stacked state in the Y-axis direction. Each second sheet member 820 is arranged on both sides of the second electrode body 700 in the Y-axis direction and on the surface in the Z-axis direction, thereby sandwiching and securing the second electrode body 700 in the Y-axis direction, thereby more reliably securing the positive electrode plate 740, negative electrode plate 750, and separators 761 and 762.

[0058] The second sheet member 821 is arranged (attached) at a position close to the tab bundle 720 between the tab bundles 720 and 730 of the second electrode body 700. The second sheet member 821 is arranged from the surface of the second electrode body 700 in the negative Y-axis direction (the surface on the first electrode body 600 side), across the surface of the second electrode body 700 in the positive Z-axis direction, to the surface of the second electrode body 700 in the positive Y-axis direction (the surface opposite the first electrode body 600). In other words, the second sheet member 821 is arranged in an attached state from the outer surface of the electrode body flat portion 711 to the outer surface of the electrode body flat portion 712 at the ends of the electrode body flat portions 711 and 712 in the positive Z-axis direction and at the center in the X-axis direction.

[0059] The second sheet member 822 is arranged (attached) at a position far from the tab bundle 720 of the second electrode body 700 in the negative X-axis direction of the tab bundle 720. Similar to the second sheet member 821, the second sheet member 822 is arranged from the surface of the second electrode body 700 in the negative Y-axis direction, passing through the surface in the positive Z-axis direction, to the surface in the positive Y-axis direction. In other words, the second sheet member 822 is arranged in an attached state, extending from the outer surface of the electrode body flat portion 711 to the outer surface of the electrode body flat portion 712, at the ends of the electrode body flat portions 711 and 712 in the positive Z-axis direction and the negative X-axis direction. The second sheet member 822 has a smaller width than the second sheet member 821 in the X-axis direction, and a length equivalent to that of the second sheet member 821 in the Z-axis direction.

[0060] The second sheet member 823 is arranged (attached) at a position far from the tab bundle 730 of the second electrode body 700 in the positive X-axis direction of the tab bundle 730. Like the second sheet member 821, the second sheet member 823 is also arranged from the surface of the second electrode body 700 in the negative Y-axis direction, passing through the surface in the positive Z-axis direction, to the surface in the positive Y-axis direction. In other words, the second sheet member 823 is arranged in an attached state, extending from the outer surface of the electrode body flat portion 711 to the outer surface of the electrode body flat portion 712, at the ends of the electrode body flat portions 711 and 712 in the positive Z-axis direction and the positive X-axis direction. The second sheet member 823 has a smaller width than the second sheet member 821 in the X-axis direction and the same width as the second sheet member 822, and a length in the Z-axis direction that is the same as the second sheet members 821 and 822.

[0061] The second sheet members 824 to 826 are respectively arranged (attached) at positions facing the second sheet members 821 to 823 in the Z-axis direction. The second sheet members 824 to 826 are arranged from the surface of the second electrode body 700 in the negative Y-axis direction (the surface on the first electrode body 600 side), across the surface of the second electrode body 700 in the negative Z-axis direction, to the surface of the second electrode body 700 in the positive Y-axis direction (the surface opposite the first electrode body 600). In other words, the second sheet members 824 to 826 are arranged in an attached state from the outer surface of the electrode body flat portion 711 to the outer surface of the electrode body flat portion 712 at the ends of the electrode body flat portions 711 and 712 in the negative Z-axis direction and at the center and both ends in the X-axis direction. In this embodiment, the second sheet members 824 to 826 have a configuration obtained by rotating the second sheet members 821 to 823 by 180° around the Y-axis. That is, the second sheet members 825 and 826 have the same width in the X-axis direction, are narrower than the second sheet member 824, and have the same length in the Z-axis direction as the second sheet member 824. Furthermore, the second sheet members 821 to 826 have the same shape and size as the first sheet members 811 to 816, respectively.

[0062] 5, the first sheet members 810 (811 to 816) are disposed in different positions in the X-axis direction from the second sheet members 820 (821 to 826). That is, the first sheet members 811 and 814 are disposed further in the positive direction of the X-axis than the second sheet members 821 and 824. The first sheet members 812 and 815 are disposed further in the positive direction of the X-axis than the second sheet members 822 and 825. The first sheet members 813 and 816 are disposed further in the negative direction of the X-axis than the second sheet members 823 and 826.

[0063] As a result, as shown in FIG. 6(a) and FIG. 7, even when the first electrode assembly 600 on which the first sheet member 810 is arranged and the second electrode assembly 700 on which the second sheet member 820 is arranged are overlapped in the Y-axis direction, the first sheet member 810 and the second sheet member 820 are arranged in positions where they do not overlap. That is, at least one first sheet member 810 is arranged in a position between the first electrode assembly 600 and the second electrode assembly 700 so as not to overlap with any of the second sheet members 820. In this embodiment, all of the first sheet members 810 (811 to 816) are arranged in positions where they do not overlap with any of the second sheet members 820 (821 to 826) between the first electrode assembly 600 and the second electrode assembly 700. In other words, the portions of the first sheet members 810 (811 to 816) facing the second electrode assembly 700 and the portions of the second sheet members 820 (821 to 826) facing the first electrode assembly 600 are arranged in positions where they do not overlap with each other in the Y-axis direction. In other words, the first sheet members 810 (811 to 816) and the second sheet members 820 (821 to 826) are disposed at different positions when viewed from the Y-axis direction.

[0064] [3.3 Explanation of the configuration of the third sheet member 831 and its positional relationship with other sheet members] 6(b) and 8, one or more third sheet members 830 are arranged on the outer surfaces of the first electrode body 600 and the second electrode body 700, spanning the first electrode body 600 and the second electrode body 700. Specifically, a plurality of third sheet members 830 are arranged on the surface of the first electrode body 600 opposite to the second electrode body 700 (the surface in the negative Y-axis direction), the surfaces of the first electrode body 600 and the second electrode body 700 in the Z-axis and X-axis directions, and the surface of the second electrode body 700 opposite to the first electrode body 600 (the surface in the positive Y-axis direction). In this embodiment, three third sheet members 830 (831 to 833) are arranged on the ends of the electrode body main body 610 of the first electrode body 600 and the electrode body main body 710 of the second electrode body 700 in the positive Z-axis direction. Three third sheet members 830 (834 to 836) are arranged at the ends in the negative Z-axis direction of the electrode body main body part 610 and the electrode body main body part 710. Two third sheet members 830 (837 and 838) are arranged at the ends on both sides in the X-axis direction of the electrode body main body part 610 and the electrode body main body part 710.

[0065] These eight third sheet members 830 (831 to 838) secure (bind) the first electrode body 600 and the second electrode body 700 in a stacked state in the Y-axis direction. Each third sheet member 830 is arranged on both surfaces of the first electrode body 600 and the second electrode body 700 in the Y-axis direction and on the surface in the Z-axis direction, thereby sandwiching and securing the first electrode body 600 and the second electrode body 700 in the Y-axis direction, thereby more reliably securing the first electrode body 600 and the second electrode body 700.

[0066] The third sheet member 831 is disposed (attached) between the first sheet member 811 and the second sheet member 821 in the X-axis direction. The third sheet member 831 is disposed from the surface of the first electrode body 600 in the negative Y-axis direction (the surface opposite the second electrode body 700), through the surfaces of the first electrode body 600 and the second electrode body 700 in the positive Z-axis direction, and to the surface of the second electrode body 700 in the positive Y-axis direction (the surface opposite the first electrode body 600). In other words, the third sheet member 831 is disposed in an attached state from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 712 at the ends of the electrode body main body 610 and the electrode body main body 710 in the positive Z-axis direction and at the center in the X-axis direction. The third sheet member 831 has the same width as the first sheet member 811 and the second sheet member 821 in the X-axis direction, and is longer than the first sheet member 811 and the second sheet member 821 in the Z-axis direction.

[0067] The third sheet member 832 is disposed (attached) in the negative X-axis direction of the first sheet member 812 and the second sheet member 822. Similar to the third sheet member 831, the third sheet member 832 is disposed from the surface of the first electrode body 600 in the negative Y-axis direction, through the surfaces of the first electrode body 600 and the second electrode body 700 in the positive Z-axis direction, to the surface of the second electrode body 700 in the positive Y-axis direction. In other words, the third sheet member 832 is disposed in an attached state, extending from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 712, at the ends of the electrode body main body 610 and the electrode body main body 710 in the positive Z-axis direction and the negative X-axis direction. The third sheet member 832 is narrower than the third sheet member 831 in the X-axis direction and has a width equal to that of the first sheet member 812 and the second sheet member 822, and is shorter than the third sheet member 831 in the Z-axis direction and has a length equal to that of the first sheet member 812 and the second sheet member 822.

[0068] The third sheet member 833 is disposed (attached) in the positive direction of the X axis to the first sheet member 813 and the second sheet member 823. Like the third sheet member 831, the third sheet member 833 is also disposed from the surface of the first electrode body 600 in the negative Y axis direction, through the surfaces of the first electrode body 600 and the second electrode body 700 in the positive Z axis direction, and to the surface of the second electrode body 700 in the positive Y axis direction. That is, the third sheet member 833 is disposed in an attached state from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 712 at the ends of the electrode body main body 610 and the electrode body main body 710 in the positive Z axis direction and the positive X axis direction. The third sheet member 833 has a smaller width than the third sheet member 831 in the X axis direction, and has the same width as the third sheet member 832 (the same width as the first sheet member 813 and the second sheet member 823), and has the same length as the third sheet member 832 in the Z axis direction.

[0069] The third sheet members 834 to 836 are respectively arranged (attached) at positions facing the third sheet members 831 to 833 in the Z-axis direction. The third sheet members 834 to 836 are arranged from the surface of the first electrode body 600 in the negative Y-axis direction (the surface opposite the second electrode body 700), through the surfaces of the first electrode body 600 and the second electrode body 700 in the positive Z-axis direction, to the surface of the second electrode body 700 in the positive Y-axis direction (the surface opposite the first electrode body 600). In other words, the third sheet members 834 to 836 are arranged in an attached state from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 712 at the ends in the negative Z-axis direction and at the center and both ends in the X-axis direction of the electrode body main body 610 and the electrode body main body 710. In the present embodiment, third sheet members 834 to 836 have a configuration obtained by rotating third sheet members 831 to 833 by 180° around the Y axis. That is, third sheet members 835 and 836 have the same width in the X axis direction but are narrower than third sheet member 834, and have the same length in the Z axis direction but are shorter than third sheet member 834.

[0070] The third sheet member 837 is disposed (attached) to the ends of the first electrode body 600 and the second electrode body 700 in the negative X-axis direction. The third sheet member 837 is disposed from the surface of the first electrode body 600 in the negative Y-axis direction, through the surfaces of the first electrode body 600 and the second electrode body 700 in the negative X-axis direction, and to the surface of the second electrode body 700 in the positive Y-axis direction. In other words, the third sheet member 837 is disposed in an attached state from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 712 at the ends of the electrode body main body 610 and the electrode body main body 710 in the negative X-axis direction and at the center in the Z-axis direction. Specifically, the third sheet member 837 is disposed from the outer surface of the electrode body flat portion 611, through the outer surfaces of the electrode body curved portions 613 and 713, and to the outer surface of the electrode body flat portion 712, in a state of being attached to these outer surfaces. The third sheet member 837 is disposed between the first sheet member 812, the second sheet member 822, and the third sheet member 832 and the first sheet member 815, the second sheet member 825, and the third sheet member 835.

[0071] The third sheet member 838 is disposed (attached) to the ends of the first electrode body 600 and the second electrode body 700 in the positive direction along the X axis. The third sheet member 838 is disposed from the surface of the first electrode body 600 in the negative direction along the Y axis, through the surfaces of the first electrode body 600 and the second electrode body 700 in the positive direction along the X axis, and to the surface of the second electrode body 700 in the positive direction along the Y axis. In other words, the third sheet member 838 is disposed in an attached state from the outer surface of the electrode body flat portion 611 to the outer surface of the electrode body flat portion 712 at the ends of the electrode body main body 610 and the electrode body main body 710 in the positive direction along the X axis and at the center in the Z axis direction. Specifically, the third sheet member 838 is disposed from the outer surface of the electrode body flat portion 611, through the outer surfaces of the electrode body curved portions 614 and 714, and to the outer surface of the electrode body flat portion 712, in a state of being attached to these outer surfaces. Third sheet member 838 is disposed between first sheet member 813, second sheet member 823, and third sheet member 833 and first sheet member 816, second sheet member 826, and third sheet member 836. In the present embodiment, third sheet member 838 has a configuration in which third sheet member 837 is rotated 180° around the Y axis.

[0072] In this way, at least one third sheet member 830 (837, 838) is arranged on a surface of the first electrode body 600 and the second electrode body 700 that is different from all of the first sheet members 810 (811-816). Similarly, at least one third sheet member 830 (837, 838) is arranged on a surface of the first electrode body 600 and the second electrode body 700 that is different from all of the second sheet members 820 (821-826).

[0073] With the above-described configuration, the third sheet members 830 (831 to 838) are disposed at positions different from the first sheet members 810 (811 to 816) and the second sheet members 820 (821 to 826). That is, at least one first sheet member 810 is disposed at a position where it does not overlap with any of the third sheet members 830 on the surface of the first electrode body 600 opposite the second electrode body 700. At least one second sheet member 820 is disposed at a position where it does not overlap with any of the third sheet members 830 on the surface of the second electrode body 700 opposite the first electrode body 600. In this embodiment, all of the first sheet members 810 (811 to 816) are disposed at positions where it does not overlap with any of the third sheet members 830 (831 to 838) on the surface of the first electrode body 600 opposite the second electrode body 700. All of the second sheet members 820 (821 to 826) are arranged on the surface of the second electrode body 700 opposite to the first electrode body 600 at positions that do not overlap with all of the third sheet members 830 (831 to 838).

[0074] In other words, a portion of the first sheet member 810 (811-816) opposite the second electrode body 700 and a portion of the third sheet member 830 (831-838) opposite the second electrode body 700 are arranged in positions that do not overlap in the Y-axis direction. A portion of the second sheet member 820 (821-826) opposite the first electrode body 600 and a portion of the third sheet member 830 (831-838) opposite the first electrode body 600 are arranged in positions that do not overlap in the Y-axis direction. In further other words, the first sheet member 810 (811-816), the second sheet member 820 (821-826), and the third sheet member 830 (831-838) are arranged in different positions when viewed from the Y-axis direction.

[0075] [4. Explanation of effects] As described above, according to the energy storage device 10 of this embodiment of the present invention, at least one first sheet member 810 is disposed between the first electrode body 600 and the second electrode body 700 in a position where it does not overlap with any of the second sheet members 820, or in a position where it does not overlap with any of the third sheet members 830 on the surface of the first electrode body 600 opposite the second electrode body 700. In this way, when the first sheet member 810 and the second sheet member 820 or the third sheet member 830 are disposed on the outer surface of one or both of the first electrode body 600 and the second electrode body 700, at least one first sheet member 810 is disposed in a position where it does not overlap with any of the second sheet members 820 or any of the third sheet members 830. This makes it possible to prevent overlap between the first sheet member 810 and the second sheet member 820 or the third sheet member 830. In this embodiment, overlap between the first sheet member 810 and both the second sheet member 820 and the third sheet member 830 can be prevented. Therefore, it is possible to prevent the size of the electrode body including the sheet member from increasing, thereby achieving a smaller size or a higher capacity of the energy storage device 10. Furthermore, by arranging the first sheet member 810 and the second sheet member 820 or the third sheet member 830 on the outer surface of one or both of the first electrode body 600 and the second electrode body 700, it is possible to prevent the first electrode body 600 and the second electrode body 700 from shifting during transportation and to prevent contamination (metal powder, etc.) from being mixed in.

[0076] By arranging all of the first sheet members 810 in positions where they do not overlap with any of the second sheet members 820, it is possible to further reduce overlap between the first sheet members 810 and the second sheet members 820. This makes it possible to further reduce the size of the electrode body including the sheet members from increasing, thereby enabling the energy storage device 10 to be made smaller or have a higher capacity.

[0077] By arranging all of the first sheet members 810 in positions where they do not overlap with any of the third sheet members 830, it is possible to further reduce overlap between the first sheet members 810 and the third sheet members 830. This makes it possible to further reduce the size of the electrode body including the sheet members, and to achieve a reduction in size or a higher capacity of the energy storage device 10.

[0078] By arranging at least one second sheet member 820 in a position where it does not overlap any of the third sheet members 830, it is possible to prevent overlapping between the second sheet member 820 and the third sheet member 830. This prevents the electrode body, including the sheet members, from becoming larger, and allows for a reduction in size or a higher capacity of the energy storage device 10.

[0079] By arranging all of the second sheet members 820 in positions where they do not overlap with any of the third sheet members 830, it is possible to further reduce overlap between the second sheet members 820 and the third sheet members 830. This makes it possible to further reduce the size of the electrode body including the sheet members, and to achieve a reduction in size or a higher capacity of the energy storage device 10.

[0080] By arranging the third sheet member 830 on a surface on a side different from all of the first sheet members 810 (the outer surfaces of the electrode body curved portions 613, 713 and the outer surfaces of the electrode body curved portions 614, 714), it is easy to arrange the third sheet member 830 in a position where it does not overlap with any of the first sheet members 810. This makes it easy to realize a configuration that reduces the size or increases the capacity of the energy storage device 10.

[0081] [5. Explanation of Variations] Although the energy storage element according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. The embodiment disclosed herein is illustrative in all respects, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

[0082] For example, in the above embodiment, the sizes and shapes (width in the X-axis direction, length in the Z-axis direction, etc.) of the first sheet members 810 (811 to 816), the second sheet members 820 (821 to 826), and the third sheet members 830 (831 to 838) are not particularly limited. For example, the first sheet members 812 and 813 may have different widths, may be wider than the first sheet member 811, or may have a different length from the first sheet member 811. The same applies to the first sheet members 814 to 816. The same applies to the second sheet members 821 to 826 and the third sheet members 831 to 838.

[0083] In the above embodiment, the first sheet member 810 is arranged on both surfaces of the first electrode body 600 in the Y-axis direction and on the surface in the Z-axis direction. However, it is sufficient that the first sheet member 810 is arranged between the first electrode body 600 and the second electrode body 700. The first sheet member 810 does not have to be arranged on the outer surface of the first electrode body 600 opposite the second electrode body 700, and it does not have to be arranged on the surface in the Z-axis direction of the first electrode body 600. Similarly, the second sheet member 820 does not have to be arranged on the outer surface of the second electrode body 700 opposite the first electrode body 600, and it does not have to be arranged on the surface in the Z-axis direction of the second electrode body 700. However, it is preferable that the first sheet member 810 is arranged on both surfaces of the first electrode body 600 in the Y-axis direction, because the first electrode body 600 can be sandwiched and fixed more reliably in the Y-axis direction. The same applies to the second sheet member 820.

[0084] The third sheet member 830 also does not have to be arranged on at least one of the surface of the first electrode body 600 opposite the second electrode body 700 and the surface of the second electrode body 700 opposite the first electrode body 600. In particular, in the above embodiment, the third sheet member 837 is arranged from the outer surface of the electrode body flat portion 611, through the outer surfaces of the electrode body curved portions 613 and 713, and to the outer surface of the electrode body flat portion 712. However, the third sheet member 837 may not be arranged on the outer surfaces of at least one of the electrode body flat portions 611 and 712, but may be arranged on the outer surfaces of the electrode body curved portions 613 and 713. However, it is preferable that the third sheet member 830 be arranged on the surfaces on both sides of the first electrode body 600 and the second electrode body 700 in the Y-axis direction, because this allows the first electrode body 600 and the second electrode body 700 to be sandwiched and fixed more reliably in the Y-axis direction. That is, a configuration in which the third sheet member 837 sandwiches the first electrode body 600 and the second electrode body 700 in the Y-axis direction by, for example, being disposed on the outer surfaces of the electrode body flat portions 611 and 712 is preferable because this configuration can more reliably fix the first electrode body 600 and the second electrode body 700. The same applies to the third sheet member 838.

[0085] In the above embodiment, the positions of the first sheet members 810 (811 to 816), the second sheet members 820 (821 to 826), and the third sheet members 830 (831 to 838) are not particularly limited as long as they are positioned so as not to overlap one another.

[0086] In the above embodiment, the number of first sheet components 810, second sheet components 820, and third sheet components 830 is not particularly limited. That is, the number of first sheet components 810 may be seven or more, five or less, or even one. The number of second sheet components 820 may also be seven or more, five or less, or even one. The number of third sheet components 830 may also be nine or more, seven or less, or even one. For example, in the third sheet component 830, third sheet components 831 to 836 may be arranged without third sheet components 837 and 838 being arranged, or third sheet components 837 and 838 may be arranged without third sheet components 831 to 836 being arranged. However, the latter is preferable because not arranging the third sheet members 831 to 836 allows the width of the first sheet member 810 and the second sheet member 820 to be increased, and by arranging the third sheet members 837 and 838, the first electrode body 600 and the second electrode body 700 can be stably fixed (bound).

[0087] In the above embodiment, all of the first sheet members 810, all of the second sheet members 820, and all of the third sheet members 830 are arranged in positions where they do not overlap. However, it is sufficient that at least one first sheet member 810 is arranged between the first electrode body 600 and the second electrode body 700 in a position where it does not overlap with any of the second sheet members 820, or in a position where it does not overlap with any of the third sheet members 830 on the surface of the first electrode body 600 opposite the second electrode body 700. For example, any of the first sheet members 810 may be arranged in a position where it overlaps with the second sheet member 820, or in a position where it overlaps with the third sheet member 830. Any of the second sheet members 820 may be arranged in a position where it overlaps with the third sheet member 830.

[0088] In the above embodiment, the second sheet member 820 or the third sheet member 830 may not be disposed on the first electrode assembly 600 or the second electrode assembly 700. That is, the first electrode assembly 600 and the second electrode assembly 700 may be housed in the container 100 without the third sheet member 830 disposed thereon, as shown in FIG. 6(a). Furthermore, the first electrode assembly 600 and the second electrode assembly 700 may be housed in the container 100 without the second sheet member 820 disposed thereon, as shown in FIGS. 9A and 9B, for example. FIGS. 9A and 9B are perspective views showing a configuration in which the second sheet member 820 is not disposed on the first electrode assembly 600 and the second electrode assembly 700 according to a modified example of this embodiment. Specifically, FIG. 9A is a view in which the second sheet member 820 is removed from FIG. 6(b), and FIG. 9B is a view in which the third sheet members 831 to 836 are removed from FIG. 9A. As mentioned above, the number of third sheet members 830 is not particularly limited, and it is preferable not to place third sheet members 831 to 836 rather than not to place third sheet members 837 and 838. Therefore, Figure 9B shows, as an example, a diagram in which third sheet members 831 to 836 have been removed from Figure 9A.

[0089] In the above embodiment, the first sheet member 810 is an insulating tape attached to the outer surface of the first electrode body 600. However, the first sheet member 810 may be an insulating sheet or the like wrapped around the first electrode body 600, as long as it is a sheet-like member arranged on the outer surface of the first electrode body 600. Similarly, the second sheet member 820 may be an insulating sheet or the like wrapped around the second electrode body 700, as long as it is a sheet-like member arranged on the outer surface of the second electrode body 700. Similarly, the third sheet member 830 may be an insulating sheet or the like wrapped around the first electrode body 600 and the second electrode body 700, as long as it is a sheet-like member arranged on the outer surfaces of the first electrode body 600 and the second electrode body 700.

[0090] In the above embodiment, the first electrode body 600 and the second electrode body 700 have an oval shape when viewed from the Z-axis direction, but they may also have an elliptical shape or the like, and the shape is not particularly limited. The first electrode body 600 and the second electrode body 700 are described as so-called horizontally wound electrode bodies whose winding axis is perpendicular to the lid body 120, but they may also be so-called vertically wound electrode bodies whose winding axis is parallel to the lid body 120. The shape of the first electrode body 600 and the second electrode body 700 is not limited to a wound type, and may be a stack type in which flat electrode plates are stacked, or a shape in which electrode plates are folded in an accordion-like shape, etc. The first electrode body 600 and the second electrode body 700 do not necessarily have tabs (tab bundles).

[0091] Any combination of the above-described embodiments and modifications is also included within the scope of the present invention.

[0092] The present invention can be realized not only as such a storage element 10, but also as a combination of a first electrode body 600 and a second electrode body 700 with a first sheet member 810 and a second sheet member 820 or a third sheet member 830. [Industrial Applicability]

[0093] The present invention can be applied to an electric storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0094] 10. Energy storage element 100 containers 110 Container body 111 Long side wall 112 Short side wall 113 Bottom wall 120 Lid 200 electrode terminal 300 Upper Gasket 400 Lower Gasket 500 current collector 600 First electrode body 610, 710 Electrode body part 611, 612, 711, 712 Flat part of electrode body 613, 614, 713, 714 Electrode body curved part 620, 630, 720, 730 Tab Bundle 640, 740 positive plate 641, 651, 741, 751 tabs 650, 750 negative plate 661, 662, 761, 762 separator 700 Second electrode body 810, 811, 812, 813, 814, 815, 816 First sheet member 820, 821, 822, 823, 824, 825, 826 Second sheet member 830, 831, 832, 833, 834, 835, 836, 837, 838 Third sheet member

Claims

1. A first electrode body in which electrode plates are stacked; a second electrode body in which electrode plates are stacked; one or more first sheet members disposed on the outer surface of the first electrode body and at a position including a gap between the first electrode body and the second electrode body, and on the outer surface of the first electrode body and at an end of the electrode plates, the first sheet members being surfaces extending along the stacking direction of the electrode plates and being formed by the end of the stacked electrode plates; one or more second sheet members disposed on an outer surface of the second electrode body and at a position including a gap between the first electrode body and the second electrode body, and one or more third sheet members disposed on the outer surfaces of the first electrode body and the second electrode body across the first electrode body and the second electrode body, the one or more second sheet members being disposed on the outer surfaces of the first electrode body and the second electrode body and being located at an end of the electrode plates and extending in the stacking direction of the electrode plates, the one or more third sheet members being disposed on the outer surfaces of the first electrode body and the second electrode body across the first electrode body and the second electrode body, At least one of the first sheet members is disposed between the first electrode body and the second electrode body at a position where it does not overlap any of the second sheet members, or at a position where it does not overlap any of the third sheet members on the surface of the first electrode body opposite to the second electrode body. Energy storage element.

2. the energy storage element includes the one or more second sheet members, All of the first sheet members are disposed between the first electrode body and the second electrode body at positions where they do not overlap with any of the second sheet members. The energy storage element according to claim 1 .

3. the energy storage element includes the one or more third sheet members, All of the first sheet members are arranged on the surface of the first electrode body opposite to the second electrode body at positions where they do not overlap with all of the third sheet members. The energy storage element according to claim 1 or 2.

4. the energy storage element includes the one or more second sheet members and the one or more third sheet members, At least one of the second sheet members is disposed on a surface of the second electrode body opposite to the first electrode body at a position where it does not overlap any of the third sheet members. The energy storage element according to any one of claims 1 to 3.

5. All of the second sheet members are arranged on the surface of the second electrode body opposite to the first electrode body at positions where they do not overlap with all of the third sheet members. The energy storage element according to claim 4.

6. the energy storage element includes the one or more third sheet members, At least one of the third sheet members is disposed on a surface of the first electrode body and the second electrode body that is different from all of the first sheet members. The energy storage element according to any one of claims 1 to 5.

7. A first electrode body; A second electrode body; one or more first sheet members disposed on an outer surface of the first electrode body and at positions including between the first electrode body and the second electrode body; one or more third sheet members disposed on outer surfaces of the first electrode body and the second electrode body across the first electrode body and the second electrode body, At least one of the first sheet members is disposed on a surface of the first electrode body opposite to the second electrode body at a position where it does not overlap any of the third sheet members. Energy storage element.

8. All of the first sheet members are arranged on the surface of the first electrode body opposite to the second electrode body at positions where they do not overlap with all of the third sheet members. The energy storage element according to claim 7 .

9. Further comprising one or more second sheet members arranged on the outer surface of the second electrode body and at a position including between the first electrode body and the second electrode body, At least one of the second sheet members is disposed on a surface of the second electrode body opposite to the first electrode body at a position where it does not overlap any of the third sheet members. The energy storage element according to claim 7 or 8.

10. All of the second sheet members are arranged on the surface of the second electrode body opposite to the first electrode body at positions where they do not overlap with all of the third sheet members. The energy storage element according to claim 9 .

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