阅读说明：本技术 蓄电元件 (Electric storage element ) 是由 小川真澄 于 2019-03-27 设计创作，主要内容包括：本发明提供一种蓄电元件(10),具备电极体(400)、正极集电体(130)和绝缘片材(500),电极体(400)具有主体部(401)和从主体部(401)突出并与正极集电体(130)连接的连接部(410),绝缘片材(500)具有与主体部(401)的侧面对置的片材侧面部(510)和从片材侧面部(510)延伸设置的片材延伸设置部(520),片材延伸设置部(520)固定于电极体(400)。(The invention provides an electricity storage element (10), comprising an electrode body (400), a positive electrode collector (130), and an insulating sheet (500), wherein the electrode body (400) has a main body part (401) and a connecting part (410) protruding from the main body part (401) and connected to the positive electrode collector (130), the insulating sheet (500) has a sheet side surface part (510) facing the side surface of the main body part (401) and a sheet extension part (520) extending from the sheet side surface part (510), and the sheet extension part (520) is fixed to the electrode body (400).)

1. An electric storage element comprising an electrode body, a current collector, and an insulating sheet,

the electrode body has:

a main body portion; and

a connecting portion protruding from the main body portion and connected to the current collector,

the insulating sheet has:

a sheet side surface portion facing a side surface of the main body; and

a sheet extension portion extended from the side surface portion of the sheet,

the sheet extension portion is fixed to the electrode body.

2. The power storage element according to claim 1,

the sheet extension setting portion is fixed to the connecting portion.

3. The power storage element according to claim 1 or 2, wherein,

the sheet extension portion is disposed between the connection portion and the current collector and/or between a baffle plate that sandwiches the connection portion together with the current collector and the connection portion, and is fixed to the electrode body.

4. The power storage element according to any one of claims 1 to 3,

the connecting portion and the current collector have a joint portion that is joined to each other,

an opening is formed in the sheet extension portion,

the joint portion is disposed to penetrate the opening portion.

5. The power storage element according to any one of claims 1 to 4,

the electrode body has a plurality of the connection portions arranged in a direction intersecting a protruding direction of the connection portion from the main body portion,

the sheet extension portion is arranged to extend over the plurality of connection portions.

6. The power storage element according to any one of claims 1 to 4,

the electrode body has a plurality of the connection portions arranged in a direction intersecting a protruding direction of the connection portion from the main body portion,

the insulating sheet has a plurality of sheet extending portions extending from the sheet side surface portion in correspondence with the plurality of connecting portions, respectively.

Technical Field

The present invention relates to an electric storage element including an electrode body and an insulating sheet covering a side surface of the electrode body.

Background

Conventionally, an electric storage element including an electrode body and an insulating sheet covering a side surface of the electrode body is known. Patent document 1 discloses a prismatic nonaqueous electrolyte battery (power storage element) in which a side surface of a battery element (electrode body) is covered with an insulating sheet and accommodated in a battery can (container main body).

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2005-302529

Disclosure of Invention

Problems to be solved by the invention

In the case of the conventional power storage device described above, it may be difficult to manufacture the power storage device.

The invention aims to provide an electric storage element which can be easily manufactured.

Means for solving the problems

An electric storage element according to one aspect of the present invention is an electric storage element including an electrode body having a main body portion and a connection portion protruding from the main body portion and connected to the current collector, a current collector, and an insulating sheet having a sheet side surface portion facing a side surface of the main body portion and a sheet extension portion extending from the sheet side surface portion, the sheet extension portion being fixed to the electrode body.

The present invention can be realized not only as such an electric storage element but also as an electrode body and an insulating sheet.

Effects of the invention

According to the power storage element of the present invention, it can be easily manufactured.

Drawings

Fig. 1 is a perspective view showing an external appearance of an electric storage device according to an embodiment.

Fig. 2 is an exploded perspective view of the power storage device according to the embodiment.

Fig. 3 is a perspective view showing the structure of the electrode body according to the embodiment.

Fig. 4 is a plan view illustrating the structure of the insulating sheet according to the embodiment.

Fig. 5 is a cross-sectional view showing the structure of the power storage element according to the embodiment.

Fig. 6 is a perspective view and a cross-sectional view showing a joining structure of a connection portion between the positive electrode collector and the electrode body according to the embodiment.

Fig. 7 is an exploded perspective view of an electric storage device according to a modification of the embodiment.

Fig. 8 is a diagram illustrating the arrangement positions of the central opening and the end opening formed in the sheet extension portion of the insulating sheet according to the modification of the present embodiment.

Detailed Description

In the above-described conventional power storage device, it may be difficult to manufacture the power storage device. As disclosed in patent document 1, when the end of the insulating sheet is disposed on the cover side of the container, the insulating sheet may be displaced when the container body and the cover are fitted to each other, and the end of the insulating sheet may be sandwiched between the container body and the cover. Even when the end portion of the insulating sheet is not disposed on the lid side of the container, the end portion of the insulating sheet may be caught by the edge of the container main body when the electrode body is inserted into the container main body. In view of these circumstances, it may be difficult to manufacture the power storage device in the conventional power storage device.

An electric storage element according to one aspect of the present invention is an electric storage element including an electrode body having a main body portion and a connection portion protruding from the main body portion and connected to the current collector, a current collector, and an insulating sheet having a sheet side surface portion facing a side surface of the main body portion and a sheet extension portion extending from the sheet side surface portion, the sheet extension portion being fixed to the electrode body.

In the electric storage element, the electrode body has a connection portion protruding from the main body and connected to the current collector, the insulating sheet has a sheet side surface portion facing the side surface of the main body of the electrode body, and a sheet extension portion extending from the sheet side surface portion, and the sheet extension portion is fixed to the electrode body. By fixing the sheet extension portion of the insulating sheet to the electrode body in this manner, it is possible to suppress the end portion of the insulating sheet (sheet extension portion) or the end portion of the insulating sheet from being caught by the container main body and the cover at the end edge of the container main body when manufacturing the electricity storage element. This makes it possible to easily manufacture the power storage element.

The sheet extension setting portion may be fixed to the connecting portion.

Thereby, the sheet extension portion is fixed to the connecting portion of the electrode body. That is, the connecting portion of the electrode body is a portion protruding from the main body portion of the electrode body, and thus the sheet extension portion is easily fixed. Therefore, the energy storage element can be more easily manufactured by fixing the sheet extension portion to the connecting portion of the electrode body. Since the relative positional deviation between the sheet extension portion and the connecting portion of the electrode body can be suppressed, the connection portion of the electrode body and the container can be more reliably insulated.

The sheet extension portion may be disposed between the connection portion and the current collector and/or between a baffle plate and the connection portion, and the baffle plate may be fixed to the electrode body so as to sandwich the connection portion together with the current collector.

Thus, the sheet extension portion is disposed between the connection portion of the electrode body and the current collector and/or between the baffle and the connection portion of the electrode body, and is fixed to the electrode body. In this way, the sheet extension portion can be easily fixed to the connecting portion of the electrode body by sandwiching the sheet extension portion between the connecting portion and the current collector or between the baffle and the connecting portion of the electrode body. This makes it possible to manufacture the power storage element more easily.

The connection portion and the current collector may have a joint portion joined to each other, an opening may be formed in the sheet extension portion, and the joint portion may be disposed so as to penetrate through the opening.

Thus, the connection portion of the electrode body and the junction portion of the current collector are disposed so as to penetrate through the opening formed in the sheet extension portion. In this way, by forming the joint portion of the electrode body and the current collector in the opening of the sheet extension portion, the portions of the electrode body and the current collector to be joined can be selectively brought into contact with each other to be joined, and the other portions can be secured in insulation. For example, in the case of joining by resistance welding, since the sheet extension portion can suppress energization in an unintended path, by concentrating power at a place to be joined, it is possible to improve joining strength and suppress the risk of occurrence of spatter. This also makes it possible to easily manufacture the power storage element.

The electrode body may have a plurality of connecting portions arranged in a direction intersecting a protruding direction of the connecting portion from the main body portion, and the sheet extension portion may be arranged to extend over the plurality of connecting portions.

Thus, the electrode body has a plurality of connecting portions, and the sheet extending portion is arranged to extend over the plurality of connecting portions. In this way, since the sheet extension portion is disposed over the plurality of connection portions of the electrode body, the sheet extension portion can be firmly fixed to the electrode body, and therefore, the electric storage element can be easily manufactured.

The electrode body may have a plurality of connecting portions arranged in a direction intersecting a protruding direction of the connecting portion from the main body portion, and the insulating sheet may have a plurality of sheet extending portions extending from the sheet side surface portion in correspondence with the plurality of connecting portions, respectively.

In this way, since the insulating sheet has the plurality of sheet extension portions extending in correspondence with the plurality of connection portions of the electrode body, respectively, the electrolyte can be impregnated between the plurality of sheet extension portions when injecting the electrolyte. This can improve the liquid filling property while ensuring insulation between the connecting portion protruding from the electrode body and the container.

Hereinafter, an electric storage device according to an embodiment (and a modification thereof) of the present invention will be described with reference to the drawings. The embodiments described below represent general or specific examples. The numerical values, shapes, materials, components, arrangement positions of components, connection modes, manufacturing steps, and the order of manufacturing steps, etc. shown in the following embodiments are examples, and the gist thereof is not limited to the invention. Among the components in the following embodiments, components that are not described in an independent claim showing the highest concept will be described as arbitrary components. In the drawings, the dimensions and the like are not strictly illustrated.

In the description of the following embodiments and the drawings, the direction in which a pair of electrode terminals (a positive electrode terminal and a negative electrode terminal) of an electric storage element are arranged, the direction in which a pair of collectors (a positive electrode collector and a negative electrode collector) are arranged, or the facing direction of the short side surfaces of a container is defined as the X-axis direction. The opposing direction of the long side surfaces of the container, the short side direction of the short side surfaces of the container, or the thickness direction of the container is defined as the Y-axis direction. The Z-axis direction is defined as the direction in which the container main body and the lid of the electric storage element are aligned, the longitudinal direction of the short side surface of the container, the winding axis direction of the electrode body, or the vertical direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are directions intersecting with each other (orthogonal in the present embodiment). In the following description, the Z-axis direction is referred to as the vertical direction for convenience of description. In the following description, the positive X-axis direction represents the arrow direction of the X-axis, and the negative X-axis direction represents the direction opposite to the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction.

(embodiment mode)

[1 full description of the storage element 10 ]

First, a general description of the power storage element 10 according to the present embodiment will be given with reference to fig. 1 to 5. Fig. 1 is a perspective view showing an external appearance of an electric storage device 10 according to the present embodiment. Fig. 2 is an exploded perspective view of the power storage element 10 according to the present embodiment. Fig. 3 is a perspective view showing the structure of the electrode body 400 according to the present embodiment. Fig. 3 shows a structure in which the electrode body 400 shown in fig. 2 is partially wound and the connection portions 410 and 420 (joints 431 and 441) are projected in the positive Z-axis direction. Fig. 4 is a plan view illustrating the structure of the insulating sheet 500 according to the present embodiment. Fig. 4 illustrates a structure in a state where the insulating sheet 500 illustrated in fig. 2 is developed. Fig. 5 is a cross-sectional view showing the structure of the power storage element 10 according to the present embodiment. Fig. 5 is a cross-sectional view showing a structure in a case where the energy storage device 10 of fig. 1 is cut on a plane parallel to a YZ plane passing through a V-V line, and the container body 110 of the container 100 is omitted and illustrated.

The power storage element 10 is a secondary battery capable of charging electric power and discharging electric power, and specifically is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used as a battery for driving or starting an engine of a vehicle such as an Electric Vehicle (EV), a Hybrid Electric Vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), a motorcycle, a water vehicle, a snowmobile, an agricultural machine, or a construction machine. The power storage element 10 is not limited to the nonaqueous electrolyte secondary battery, and may be a secondary battery other than the nonaqueous electrolyte secondary battery, or may be a capacitor. The power storage element 10 may be a primary battery that can use the stored electric power without being charged by the user, instead of a secondary battery. The power storage element 10 may be a battery using a solid electrolyte. In the present embodiment, the rectangular parallelepiped (rectangular) electric storage element 10 is illustrated, but the shape of the electric storage element 10 is not limited to the rectangular parallelepiped shape, and may be a polygonal prism shape, a cylindrical shape, a long cylindrical shape, or the like other than the rectangular parallelepiped shape, or may be a laminate type electric storage element.

As shown in fig. 1, the energy storage device 10 includes a container 100 having a container body 110 and a lid 120, a positive electrode terminal 200, and a negative electrode terminal 300. As shown in fig. 2, the container 100 accommodates therein the positive electrode collector 130, the negative electrode collector 140, the electrode body 400, the insulating sheet 500, the separator 800, and the like.

Gaskets and the like for improving electrical insulation and airtightness are disposed between the lid 120 and the positive electrode terminal 200 and the negative electrode terminal 300, and between the lid 120 and the positive electrode current collector 130 and the negative electrode current collector 140, but the description thereof is omitted. The electrolyte (nonaqueous electrolyte) is sealed in the container 100, but not shown. The type of the electrolyte is not limited as long as the performance of the power storage element 10 is not impaired, and various electrolytes can be selected. In addition to the above-described components, a separator or the like disposed above the electrode body 400 may be disposed.

[1.1 description of the structures of the case 100, the positive electrode terminal 200, and the negative electrode terminal 300 ]

The container 100 is a rectangular parallelepiped (box-shaped) case including a rectangular cylindrical bottomed container body 110 and a lid 120 as a plate-like member for closing an opening of the container body 110. The container 100 is configured such that after the electrode body 400 and the like are accommodated inside the container main body 110, the lid 120 and the container main body 110 are welded or the like to seal the inside. The lid 120 is provided with a gas discharge valve 121 for releasing the pressure when the pressure in the container 100 rises, and a liquid filling portion 122 for filling the container 100 with the electrolyte. The material of the lid 120 and the container body 110 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, an aluminum alloy, iron, and a plated steel sheet.

The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode plate of the electrode assembly 400 via the positive electrode collector 130. The negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 400 via the negative electrode collector 140. That is, the positive electrode terminal 200 and the negative electrode terminal 300 are metal electrode terminals for leading out the electric power stored in the electrode assembly 400 to the space outside the electric storage element 10 and for introducing the electric power into the internal space of the electric storage element 10 to store the electric power in the electrode assembly 400. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid 120. The positive electrode terminal 200 and the negative electrode terminal 300 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[1.2 description of the structure of the electrode body 400 ]

As shown in fig. 3, the electrode body 400 is an electric storage element (electric power generation element) that includes the positive electrode plate 430, the negative electrode plate 440, and the separators 450a and 450b and is capable of storing electric power. Specifically, the electrode body 400 is formed by winding an object that is layered so that the separator 450a or 450b is interposed between the positive electrode plate 430 and the negative electrode plate 440. That is, the electrode body 400 is formed by stacking the positive electrode plates 430, the separators 450a, the negative electrode plates 440, and the separators 450b in this order, so that the positive electrode plates 430 and the negative electrode plates 440, and the separators 450a and 450b are alternately stacked and wound. In the present embodiment, the oval shape is illustrated as the cross-sectional shape of the electrode body 400, but an oval shape, a circular shape, a polygonal shape, or the like may be used.

The positive electrode plate 430 is an electrode plate (electrode plate) in which a positive electrode active material layer is formed on the surface of a positive electrode base material layer that is a long strip-shaped metal foil containing aluminum, an aluminum alloy, or the like. As the positive electrode active material used in the positive electrode active material layer, any known material may be used as long as it can occlude and release lithium ions. As the positive electrode active material, LiMPO can be used₄、LiMSiO₄、LiMBO₃Polyanion compounds (where M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), lithium titanate, and LiMn₂O₄Or LiMn_1.5Ni_0.5O₄Isospinel type lithium manganese oxide and LiMO₂(M is one or two or more transition metal elements selected from Fe, Ni, Mn, Co, etc.) and the like.

The negative electrode plate 440 is an electrode plate (electrode plate) in which a negative electrode active material layer is formed on the surface of a negative electrode base material layer which is a long strip-shaped metal foil containing copper, a copper alloy, or the like. As the negative electrode active material used in the negative electrode active material layer, any known material may be used as long as it can occlude and release lithium ions. Examples of the negative electrode active material include lithium metal, lithium alloys (alloys containing lithium metal such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood's alloy), alloys capable of occluding and releasing lithium, and carbon materials (for example, graphite, non-graphitizable carbon, low graphitizable carbon)Warm-fired carbon, amorphous carbon, etc.), silicon oxide, metal oxide, lithium metal oxide (Li)₄Ti₅O₁₂Etc.), polyphosphate compound, or Co generally referred to as switching negative electrode₃O₄Or Fe₂P, and the like, and compounds of group 14 to group 16 elements, and the like.

The spacers 450a and 450b are microporous sheets containing resin. As the material of the spacers 450a and 450b, a known material can be used as appropriate as long as the performance of the power storage element 10 is not impaired.

The positive electrode plate 430 has a plurality of rectangular tabs 431 protruding outward at one end in the winding axis direction. Similarly, the negative electrode plate 440 has a plurality of rectangular tabs 441 protruding outward at one end in the winding axis direction. The plurality of tabs 431 and 441 are portions (active material non-formation portions or active material non-application portions) where the active material is not formed (applied) and the base material layer is exposed. The winding axis is a virtual axis that serves as a central axis when the positive electrode plate 430, the negative electrode plate 440, and the like are wound, and in the present embodiment, is a straight line parallel to the Z-axis direction passing through the center of the electrode body 400.

The plurality of tabs 431 and the plurality of tabs 441 are disposed on the same end portion in the winding axis direction (end portion on the Z-axis positive direction side in fig. 3), and are laminated at predetermined positions of the electrode body 400 by laminating the positive electrode plates 430 and the negative electrode plates 440. As a result, connection unit 410 formed by stacking a plurality of tabs 431 and connection unit 420 formed by stacking a plurality of tabs 441 are formed in electrode body 400. The connection portions 410 and 420 converge toward the center in the stacking direction (Y-axis direction in fig. 3), for example, and are joined to the positive electrode current collector 130 and the negative electrode current collector 140 by welding or the like.

In this way, the connection portions 410 and 420 are portions that are disposed so as to protrude from the main body portion 401 of the electrode body 400 and are connected to the positive electrode collector 130 and the negative electrode collector 140. The main body portion 401 is a portion constituting the main body of the electrode assembly 400, and specifically is a portion of the electrode assembly 400 other than the connection portions 410 and 420 (other than the joints 431 and 441). That is, the body 401 is a portion of the positive electrode plate 430 and the negative electrode plate 440 where the active material is formed (applied), and a portion (active material forming portion or active material applying portion) in the shape of an elongated cylinder formed by winding the separators 450a and 450 b.

The connecting portions 410 and 420 are arranged in the X-axis direction. That is, the electrode body 400 has a plurality of connecting portions arranged in a direction (X-axis direction) intersecting with a protruding direction (Z-axis positive direction) of the connecting portion from the main body 401. The connection portions 410 and 420 are joined to the positive electrode current collector 130 and the negative electrode current collector 140 and then bent in the Y-axis direction (see fig. 5). Specifically, the connection portions 410 and 420 are joined to the positive electrode collector 130 and the negative electrode collector 140 in a state of protruding from a part of the main body portion 401 of the electrode body 400 in the Z-axis positive direction, and are bent in the Y-axis positive direction after joining, and are provided in a state of extending in the Y-axis positive direction. That is, the connection portions 410 and 420 are portions where the plurality of joints 431 and 441 that protrude from a part of the body portion 401 of the electrode body 400 in the Z-axis positive direction and extend in the Y-axis positive direction are laminated in the Z-axis direction.

[1.3 description of the structures of the insulating sheet 500 and the separator 800 ]

The insulating sheet 500 is a sheet-like (film-like) member having electrical insulation properties, and is disposed so as to cover the electrode assembly 400 and electrically insulate the electrode assembly 400 from other members (the container 100, the positive electrode collector 130, the negative electrode collector 140, and the like). The insulating sheet 500 is made of an insulating material such as polypropylene (PP), Polyethylene (PE), Polyphenylene Sulfide (PPs), polyethylene terephthalate (PET), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), Polytetrafluoroethylene (PTFE), polybutylene terephthalate (PBT), Polyether Sulfone (PEs), or a composite material thereof.

Specifically, as shown in fig. 2 and 4, the insulating sheet 500 has a sheet side surface portion 510, a sheet extension portion 520, and a sheet bottom surface portion 530. The sheet side surface portion 510 is a rectangular and flat plate-like portion that faces the side surface of the main body portion 401 of the electrode assembly 400. That is, the sheet side surface portion 510 includes a rectangular and flat plate-shaped sheet side surface portion 510a that covers the side surface on the Y-axis negative direction side of the main body portion 401 of the electrode body 400, and a rectangular and flat plate-shaped sheet side surface portion 510b that covers the side surface on the Y-axis positive direction side of the main body portion 401 of the electrode body 400. The sheet side surface portions 510 (sheet side surface portions 510a and 510b) cover the entire side surfaces of the main body portion 401 of the electrode body 400, but may cover only a part of the side surfaces, or may be, for example, a shape curved along the main body portion 401 instead of a flat plate shape.

The sheet extension portion 520 is a rectangular and plate-like portion that is extended from the sheet side surface portion 510 toward the connection portions 410 and 420 in the Z-axis positive direction and is fixed to the electrode body 400. Specifically, the sheet extension portion 520 is disposed so as to extend from the sheet side surface portion 510 toward the connection portions 410 and 420 side of the main body portion 401 of the electrode body 400 and is fixed to the connection portions 410 and 420. That is, the sheet extension portion 520 is disposed so as to extend over the plurality of connection portions (the positive-side connection portion 410 and the negative-side connection portion 420) of the electrode body 400. In other words, the sheet extension portion 520 is extended from the sheet side surface portion 510 along the electrode body 400 (along the connection portions 410 and 420), and is disposed at a position sandwiching the connection portions 410 and 420.

The sheet extension portion 520 includes a rectangular and plate-shaped sheet extension portion 520a disposed on the Y-axis negative direction side of the connection portions 410 and 420, and a rectangular and plate-shaped sheet extension portion 520b disposed on the Y-axis positive direction side of the connection portions 410 and 420. That is, the sheet extension portion 520a is obliquely extended along the Y-axis positive direction from the edge on the Z-axis positive direction side of the sheet side surface portion 510a, is bent in the Z-axis positive direction, and is fixed to the surface on the Y-axis negative direction side of the connection portions 410 and 420. In this way, the sheet extension portion 520a is an elongated portion extending in the X-axis direction along the surface on the Y-axis negative direction side of the connection portions 410 and 420 over the connection portions 410 and 420. The sheet extension portion 520b is obliquely extended in the Y-axis negative direction from the edge of the sheet side surface portion 510b on the Z-axis positive direction side, is bent in the Z-axis positive direction, and is fixed to the surface of the connection portion 410 or 420 on the Y-axis negative direction side. In this way, the sheet extension portion 520b is an elongated portion extending in the X-axis direction along the surface of the connection portions 410 and 420 on the positive Y-axis direction side, over the connection portions 410 and 420.

The sheet extension portion 520 has an opening 521 for exposing the connection portions 410 and 420. That is, in the sheet extension portion 520a, two rectangular openings 521a that expose the surfaces of the connection portions 410 and 420 on the Y-axis negative direction side are formed at positions corresponding to the connection portions 410 and 420. In the sheet extension portion 520b, two rectangular openings 521b that expose the surfaces of the connection portions 410 and 420 in the positive Y-axis direction are formed at positions corresponding to the connection portions 410 and 420.

The sheet bottom surface portion 530 is a rectangular and flat plate-like portion disposed to face a portion on the bottom surface side (Z-axis negative direction side) of the electrode body 400. That is, the sheet bottom surface portion 530 is disposed between the sheet side surface portions 510a and 510b, and connects the edges on the Z-axis negative direction side of the sheet side surface portions 510a and 510 b. The sheet bottom surface portion 530 covers the entire bottom surface of the electrode body 400, but may cover only a part of the bottom surface, or may have a curved shape, for example, instead of a flat plate shape.

Thus, the insulating sheets 500 are not disposed on both sides of the electrode body 400 in the X-axis direction. As a result, as shown in fig. 2, the insulating sheet 500 is attached (wound) to the electrode body 400, and side openings 500a, which are openings that are substantially rectangular and extend in the Z-axis direction, are formed on both sides of the electrode body 400 in the X-axis direction. The separator 800 is inserted into the side opening 500a and attached to the electrode body 400.

The separator 800 is a columnar side separator that is disposed so as to extend in the Z-axis direction between both side surfaces of the electrode body 400 in the X-axis direction and the inner surface of the container 100, and that regulates the position of the electrode body 400 in the container 100. The separator 800 is made of an insulating material such as PP or PE similar to the insulating sheet 500, and electrically insulates both side surfaces of the electrode body 400 in the X-axis direction from the container 100.

[1.4 explanation of the structures of the positive electrode current collector 130 and the negative electrode current collector 140 ]

The positive electrode collector 130 and the negative electrode collector 140 are plate-shaped members disposed between the lid 120 and the electrode body 400, and electrically connect the positive electrode terminal 200 and the negative electrode terminal 300 to the positive electrode plate 430 and the negative electrode plate 440 of the electrode body 400. That is, one end of the positive electrode collector 130 is connected to the positive electrode terminal 200, and the other end is connected to the positive electrode-side connection portion 410 of the electrode body 400. One end of the negative electrode collector 140 is connected to the negative electrode terminal 300, and the other end is connected to the negative electrode-side connection portion 420 of the electrode body 400. The positive electrode collector 130 is made of aluminum, an aluminum alloy, or the like, as in the positive electrode base material layer of the positive electrode plate 430, and the negative electrode collector 140 is made of copper, a copper alloy, or the like, as in the negative electrode base material layer of the negative electrode plate 440.

Specifically, the positive electrode collector 130 has a terminal-side arrangement portion (terminal connection portion) 131 and an electrode-body-side arrangement portion (electrode-body connection portion) 132. The terminal-side arrangement portion 131 is a plate-shaped member that is joined to the positive electrode terminal 200 by caulking or the like and is electrically connected thereto. That is, the shaft portion (rivet portion) of the positive electrode terminal 200 is inserted into the through hole of the lid body 120 and the through hole 131a of the terminal-side arrangement portion 131 and crimped, whereby the terminal-side arrangement portion 131 is fixed to the lid body 120 together with the positive electrode terminal 200.

The electrode body-side arrangement portion 132 is a plate-like member joined to the connection portion 410 of the electrode body 400 by welding or the like. That is, the electrode body side arrangement portion 132 is joined to the connection portion 410 with the sheet extension portion 520 of the insulating sheet 500 interposed therebetween together with the connection portion 410, and thereby the sheet extension portion 520 is fixed to the electrode body side arrangement portion 132 and the connection portion 410. A detailed description of the structure in which the electrode body-side arrangement portion 132 of the positive electrode collector 130 is joined to the connection portion 410 of the electrode body 400 will be described later.

Although fig. 2 illustrates a state when the electrode body side arrangement portion 132 is joined to the connection portion 410 at the time of manufacturing the electricity storage element 10, as illustrated in fig. 5, the electrode body side arrangement portion 132 is further bent toward the terminal side arrangement portion 131 in the state of fig. 1 (the state after joining). That is, in the manufacture of the electricity storage element 10, as shown in fig. 2, the terminal-side arrangement portion 131 is joined to the positive electrode terminal 200, and the electrode-side arrangement portion 132 is joined to the connection portion 410, with the terminal-side arrangement portion 131 and the electrode-side arrangement portion 132 bent at substantially right angles with respect to the positive electrode collector 130. Then, as shown in fig. 5, from the viewpoint of space saving or the like, the electrode body-side arrangement portion 132 is further bent toward the terminal-side arrangement portion 131 so as to be substantially parallel to the terminal-side arrangement portion 131 (that is, the positive electrode collector 130 has a substantially U-shape as viewed in the X-axis direction), and the electrode body 400 or the like is accommodated in the container 100, and the state shown in fig. 1 is obtained.

Thus, the sheet extension portion 520a is disposed between the tip end of the connecting portion 410, 420 and the wall portion (cover 120) of the container 100 facing the tip end. The sheet extension portion 520b is disposed at a position where the leading end portions of the connection portions 410 and 420 are sandwiched together with the wall portion (cover 120) of the container 100.

The negative electrode collector 140 also has a terminal side arrangement portion 141 and an electrode body side arrangement portion 142, similarly to the positive electrode collector 130. The negative electrode current collector 140 has the same structure as the positive electrode current collector 130, and therefore, detailed description thereof is omitted.

[2 ] explanation of the joining structure of the positive electrode collector 130 and the connection portion 410 of the electrode body 400 ]

Next, the structure in a state where the positive electrode collector 130 and the connection portion 410 of the electrode body 400 are joined will be described in detail. Fig. 6 is a perspective view and a cross-sectional view showing a bonding structure of the positive electrode collector 130 and the connection portion 410 of the electrode body 400 according to the present embodiment. Specifically, (a) of fig. 6 is a perspective view of a state where the positive electrode collector 130, the negative electrode collector 140, and the electrode body 400 are joined, as viewed obliquely from below. In fig. 6 (a), for convenience of explanation, the structures other than the positive electrode collector 130, the negative electrode collector 140, the electrode body 400, and the insulating sheet 500 are not shown. Fig. 6 (b) is a cross-sectional view showing a cross section in a case where the structure of fig. 6 (a) is cut at a VIb-VIb cross section.

Fig. 6 shows the structure in a state where the connection portions 410 and 420 at the joining time points of the positive electrode collector 130, the negative electrode collector 140, and the electrode body 400 protrude in the positive Z-axis direction (the electrode body side arrangement portions 132 and 142 are not further bent) as described above. Fig. 6 (b) shows the structure of the positive electrode side (the positive electrode collector 130, the connection portion 410, and the like), and the structure of the positive electrode side will be described below, but the negative electrode side (the negative electrode collector 140, the connection portion 420, and the like) also has the same structure.

As shown in fig. 6, the connection portion 410 of the electrode body 400 is disposed so as to be sandwiched between the positive electrode collector 130 and the baffle 600 in the Y-axis direction (the Z-axis direction in the state of fig. 5). That is, in the present embodiment, the baffle 600 is disposed on the Y-axis positive direction side (Z-axis negative direction side in the state of fig. 5) of the connection portion 410. The baffle 600 is a cover member that protects the connection portion 410 and is disposed at a position that sandwiches the connection portion 410 together with the positive electrode collector 130. Specifically, the baffle 600 is a rectangular and flat plate-shaped member that widens in the XZ plane along the connection portion 410. The separator 600 is a metal member made of aluminum, aluminum alloy, or the like, as in the positive electrode base material layer of the positive electrode plate 430 of the electrode assembly 400, although the material is not particularly limited. The baffle plate is similarly disposed on the negative electrode side, and the material of the baffle plate on the negative electrode side is not particularly limited, but is a metal member formed of copper, a copper alloy, or the like, similarly to the negative electrode base material layer of the negative electrode plate 440 of the electrode body 400.

The sheet extension portion 520 is disposed between the connection portion 410 and the positive electrode collector 130 and between the baffle 600 and the connection portion 410. That is, the sheet extension portion 520a is disposed between the connecting portion 410 and the electrode body side disposition portion 132 of the positive electrode collector 130, and the sheet extension portion 520b is disposed between the baffle 600 and the connecting portion 410.

The connection portion 410, the positive electrode collector 130, and the baffle 600 are joined to form a joint portion 700. That is, the connection portion 410 and the positive electrode collector 130 have a joint portion 700 joined to each other. Specifically, at a position inside the opening 521 formed in the sheet extension portion 520, the connection portion 410, the positive electrode collector 130, and the baffle 600 are joined to form a joint portion 700. In this way, the joint 700 is disposed to penetrate the opening 521 (the openings 521a and 521b) of the sheet extension portion 520. In other words, the joint portion of the connection portion 410 and the positive electrode collector 130 in the joint portion 700 is disposed as the through opening 521a, and the joint portion of the baffle 600 and the connection portion 410 is disposed as the through opening 521 b. In the present embodiment, the joint 700 is a welded portion formed by resistance welding.

With such a configuration, the sheet extension portion 520 is disposed between the connecting portion 410 and the positive electrode collector 130 and between the baffle 600 and the connecting portion 410 (in the present embodiment, both of them) and fixed to the electrode body 400. That is, the sheet extension portion 520a is disposed between the connection portion 410 and the electrode body side arrangement portion 132 of the positive electrode collector 130, and is sandwiched between the connection portion 410 and the electrode body side arrangement portion 132, and is directly fixed to the connection portion 410 and the electrode body side arrangement portion 132. The sheet extension portion 520b is disposed between the flap 600 and the connecting portion 410, and is sandwiched between the flap 600 and the connecting portion 410, and is directly fixed to the flap 600 and the connecting portion 410.

[3 Explanation of Effect ]

As described above, according to the electricity storage element 10 of the embodiment of the present invention, the electrode body 400 has the connection portion 410 protruding from the main body portion 401 and connected to the positive electrode collector 130, the insulating sheet 500 has the sheet side surface portion 510 facing the side surface of the main body portion 401 of the electrode body 400, and the sheet extension portion 520 extending from the sheet side surface portion 510 and disposed on the connection portion 410 side of the main body portion 401 of the electrode body 400, and the sheet extension portion 520 is fixed to the electrode body 400. By fixing the sheet extension portion 520 of the insulating sheet 500 to the electrode body 400 in this manner, when the electricity storage element 10 is manufactured, it is possible to suppress the end portion (the sheet extension portion 520) of the insulating sheet 500 from being sandwiched between the container main body 110 and the lid body 120 or the end portion of the insulating sheet 500 from being caught at the end edge of the container main body 110. This makes it possible to easily manufacture the power storage element 10. By providing the insulating sheet 500 extending from the side surface of the main body portion 401 of the electrode body 400 and also being disposed on the connecting portion 410 side of the main body portion 401 of the electrode body 400, the connecting portion 410 side of the main body portion 401 of the electrode body 400 can be insulated.

Specifically, in the case where electrode body 400 has connection portion 410 protruding from main body portion 401, connection portion 410 of electrode body 400 may come into contact with container 100 to cause a short circuit. Therefore, by providing the sheet extension portion 520 in the insulating sheet 500, insulation between the electrode body 400 of the electrode body 400 and the container 100 can be ensured. On the other hand, the insulating sheet 500 is not highly rigid and is easy to move. As a result, the sheet extension portion 520 is easily sandwiched between the container body 110 and the lid 120 of the container 100. Therefore, by fixing the sheet extension portion 520 to another member, the sheet extension portion 520 can be prevented from being sandwiched between the container body 110 and the lid body 120. In particular, when the sheet extension portion 520 is fixed to the electrode body 400, the relative positional deviation between the insulating sheet 500 and the electrode body 400 can be suppressed, and therefore, the insulation between the container 100 and the electrode body 400 can be further secured.

The sheet extension portion 520 is fixed to the connecting portion 410 of the electrode body 400. That is, the connecting portion 410 of the electrode body 400 is a portion protruding from the main body portion 401 of the electrode body 400, and thus the sheet extension set portion 520 is easily fixed. Therefore, by fixing the sheet extension portion 520 to the connection portion 410 of the electrode body 400, the electricity storage element 10 can be manufactured more easily. Since the relative positional deviation between the sheet extension portion 520 and the connection portion 410 of the electrode body 400 can be suppressed, the connection portion 410 of the electrode body 400 and the container 100 can be more reliably insulated.

The sheet extension portion 520 is disposed between the connection portion 410 of the electrode body 400 and the positive electrode collector 130 and between the baffle 600 and the connection portion 410 of the electrode body 400, and is fixed to the electrode body 400. In this way, the sheet extension portion 520 can be easily fixed to the connection portion 410 by sandwiching the sheet extension portion 520 between the connection portion 410 of the electrode body 400 and the positive electrode collector 130 or between the baffle 600 and the connection portion 410 of the electrode body 400. This makes it possible to manufacture the power storage element 10 more easily.

The connection portion 410 of the electrode body 400 and the joint portion 700 of the positive electrode collector 130 are disposed so as to penetrate through the opening 521 formed in the sheet extension portion 520. By forming the joint 700 of the electrode body 400 and the positive electrode collector 130 in the opening 521 of the sheet extension portion 520 in this manner, the portions of the electrode body 400 and the positive electrode collector 130 to be joined can be selectively brought into contact with each other to be joined, and the other portions can be secured with insulation. In the case of performing joining by resistance welding, since the sheet extension portion 520 can suppress energization in an unintended path, by concentrating power at a place where joining is intended, it is possible to improve joining strength and suppress the risk of occurrence of spatter. This also makes it possible to easily manufacture the power storage element 10.

The electrode body 400 has a plurality of connecting portions (connecting portions 410 and 420), and the sheet extension portion 520 is disposed so as to extend over the plurality of connecting portions. In this way, since the sheet extension portion 520 is disposed over the plurality of connection portions of the electrode body 400, the sheet extension portion 520 can be firmly fixed to the electrode body 400, and thus the electricity storage element 10 can be easily manufactured. The sheet extension portion 520 can also insulate the portion between the plurality of connection portions of the electrode assembly 400.

The insulating sheet 500 has side openings 500a on both sides of the electrode body 400 in the X-axis direction, and the separator 800 is disposed in the side openings 500 a. In this way, the insulating sheet 500 may not be provided on both sides of the electrode body 400 in the X-axis direction, and therefore the structure of the insulating sheet 500 can be simplified. This makes it possible to easily manufacture the power storage element 10. Space can be saved by not providing the insulating sheets 500 on both sides of the electrode assembly 400 in the X-axis direction.

In the above description, the effects of the positive electrode side (the positive electrode collector 130 and the connection portion 410 of the electrode body 400) have been mainly described, but the same effects are also obtained with respect to the negative electrode side (the negative electrode collector 140 and the connection portion 420 of the electrode body 400).

[4 description of modified example of embodiment ]

Next, a modified example of the present embodiment will be described. In the above embodiment, the sheet extension portion 520 of the insulating sheet 500 is disposed to extend over the connection portions 410 and 420 of the electrode body 400. In the present modification, the sheet extension portion is not extended over the connection portions 410 and 420, and is disposed so as to be divided into a portion corresponding to the connection portion 410 and a portion corresponding to the connection portion 420. Fig. 7 is an exploded perspective view of the power storage element 11 according to a modification of the present embodiment. Fig. 8 is a diagram illustrating the arrangement positions of the central opening 501a and the end openings 501b and 501c formed by the sheet extension portion 520c of the insulating sheet 501 according to the modification of the present embodiment. Specifically, fig. 8 is a bottom view of the electric storage element 11 when the structure around the sheet extension portion 520c is viewed from the Z-axis negative direction side.

As shown in fig. 7, the electric storage device 11 of the present modification includes an insulating sheet 501 instead of the insulating sheet 500 of the electric storage device 10 of the above embodiment. The insulating sheet 501 has a plurality of sheet extension portions 520c instead of the sheet extension portions 520 of the insulating sheet 500 in the above embodiment. The other configurations of the power storage element 11 in the present modification are the same as the respective components of the power storage element 10 in the above embodiment, and therefore, the description thereof is omitted.

As in the above-described embodiment, the electrode assembly 400 includes a plurality of (two) connecting portions 410 and 420 arranged in a direction (X-axis direction) intersecting the protruding direction of the connecting portions 410 and 420 from the main body portion 401. The insulating sheet 501 has a plurality of sheet extension portions 520c extending from the sheet side surface portion 510 toward the plurality of connection portions 410 and 420, respectively. That is, the insulating sheet 501 has two sheet extension portions 520c, and the two sheet extension portions 520c are disposed at positions corresponding to the connecting portions 410 and 420, respectively. The two sheet extension portions 520c are formed to have a larger width in the X-axis direction than the connecting portions 410 and 420, respectively.

As shown in fig. 7 and 8, since the two sheet extension portions 520c are disposed apart from each other, a central opening 501a having a shape in which the X-axis direction central portion of the end portion on the Z-axis positive direction side of the insulating sheet 501 is cut out is formed between the two sheet extension portions 520 c. The central opening 501a is disposed to face the gas discharge valve 121. End openings 501b and 501c having a shape in which both ends in the X axis direction of the end on the Z axis positive direction side of the insulating sheet 501 are cut are formed on both sides in the X axis direction of the two sheet extension portions 520 c. The end opening 501b is disposed to face a joint (a caulking portion 210 in fig. 8) of the positive electrode terminal 200 and the positive electrode current collector 130 in the Z-axis direction. The end opening 501c is disposed to face a joint portion (a caulking portion 310 in fig. 8) of the negative electrode terminal 300 and the negative electrode current collector 140 in the Z-axis direction.

As described above, according to the power storage element 11 of the present modification example, the same effects as those of the above embodiment can be obtained. In particular, since the insulating sheet 501 has a plurality of sheet extension portions 520c extending toward the plurality of connection portions 410 and 420 of the electrode body 400, respectively, the electrolyte can enter the central opening 501a between the plurality of sheet extension portions 520c when the electrolyte is injected. Similarly, the electrolyte can also enter the end openings 501b and 501 c. This can improve the liquid injection property while ensuring insulation between the connecting portions 410 and 420 protruding from the electrode body 400 and the container 100. Since the electrolyte injection property can be improved at the time of manufacturing the power storage element 11, the power storage element 11 can be easily manufactured.

Further, since the end opening 501b is disposed to face the joint (caulking portion 210) of the positive electrode terminal 200 and the positive electrode current collector 130, the sheet extension portion 520c can be prevented from interfering with the joint operation of the positive electrode terminal 200 and the positive electrode current collector 130. This makes it possible to easily perform the operation of joining the positive electrode terminal 200 and the positive electrode current collector 130, and thus to easily manufacture the power storage element 11. The same applies to the end opening 501 c.

Since the central opening 501a is disposed to face the gas discharge valve 121 in the Z-axis direction, the sheet extension portion 520c can also suppress the blocking of the discharged gas flow when the gas discharge valve 121 is opened.

(other modification example)

The above description has been given of the power storage elements 10 and 11 according to the embodiment and the modifications thereof, but the present invention is not limited to the embodiment and the modifications thereof. That is, the embodiment and its modified examples disclosed herein are illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the scope of the claims, and includes meanings equivalent to the scope of the claims and all modifications within the scope.

In the above-described embodiment and the modifications thereof, the electrode body-side arrangement portion 132 of the positive electrode collector 130 is bent toward the terminal-side arrangement portion 131 after being joined to the connection portion 410 of the electrode body 400. However, the electrode-side arrangement portion 132 may not be bent toward the terminal-side arrangement portion 131 even after joining. Alternatively, the electrode body-side arrangement portion 132 may be bent toward the side opposite to the terminal-side arrangement portion 131 after joining. The same applies to the negative electrode current collector 140.

In the above-described embodiment and the modifications thereof, the positive electrode collector 130 is provided with the shape in which the electrode body side disposition portion 132 is bent with respect to the terminal side disposition portion 131. However, the positive electrode collector 130 may have a shape in which the electrode body side arrangement portion 132 is not bent with respect to the terminal side arrangement portion 131, that is, a flat plate shape.

In the above-described embodiment and the modifications thereof, the insulating sheet 500 (or 501, the same applies hereinafter) is provided with a sheet side surface portion 510 including sheet side surface portions 510a and 510b, a sheet extension portion 520 (or 520c, the same applies hereinafter) including sheet extension portions 520a and 520b, and a sheet bottom surface portion 530. However, the insulating sheet 500 may not have any of the sheet side surface portions 510a and 510b, may not have any of the sheet extension portions 520a and 520b, and may not have the sheet bottom surface portion 530.

In the above-described embodiment and its modifications, the sheet extension portion 520 of the insulating sheet 500 is fixed to the connection portions 410 and 420 of the electrode body 400 by joining the connection portions 410 and 420 of the electrode body 400 and the current collector. However, the sheet extension portion 520 may be fixed to the electrode body 400, and may be fixed to the connection portions 410 and 420 of the electrode body 400 by welding, adhesion, or the like, or may be fixed to any surface of the main body portion 401 of the electrode body 400 by welding, adhesion, or the like.

In the above-described embodiment and the modification thereof, the opening 521 is formed in the sheet extension portion 520 provided in the insulating sheet 500, and the joint portion 700 is disposed so as to penetrate through the opening 521. However, the opening 521 may not be formed in the sheet extension portion 520, and the joining portion 700 may be disposed on the side of the sheet extension portion 520.

In the above-described embodiment and the modification thereof, it is assumed that the energy storage element 10 (or 11, hereinafter the same applies) is provided with the baffle 600 at a position where the connection portions 410 and 420 of the electrode assembly 400 are sandwiched together with the current collectors. However, the electricity storage element 10 may be joined to the connection portions 410 and 420 of the collector and the electrode assembly 400 without providing the baffle 600. When the current collector and the connection portions 410 and 420 are bonded by ultrasonic bonding, the baffle 600 may not be provided.

In the above-described embodiment and the modifications thereof, the joint 700 is a welded portion formed by resistance welding. However, the joining method of the joining portion 700 is not limited to resistance welding, and various joining methods such as laser welding, ultrasonic joining, and caulking can be applied.

In the above-described embodiment and the modifications thereof, the connecting portions 410 and 420 of the electrode assembly 400 are portions that protrude in a rectangular shape from a part of the main body portion 401. However, the shape of the connection portions 410 and 420 is not particularly limited, and may be a polygonal shape other than a square shape, a semicircular-oblong shape, a semicircular-oval shape, or the like in a plan view. The connection portions 410 and 420 may not be a part of the body 401 but may be a portion protruding from the entire body 401.

In the above-described embodiment and the modifications thereof, the electrode body 400 is formed in a so-called transverse wound shape having a winding axis in the Z-axis direction. However, the electrode assembly 400 may have a so-called longitudinally wound winding shape having a winding axis in the X-axis direction, or a shape in which the electrode plates are folded in a corrugated shape. The electrode body 400 may be a stacked electrode body in which a plurality of flat plate-like electrode plates are stacked. That is, the configurations in the above-described embodiment and the modifications thereof can also be applied to any electrode body provided with a connection portion.

In the above-described embodiment and the modifications thereof, both of the positive electrode side and the negative electrode side are configured as described above. However, the positive electrode side or the negative electrode side may not have the above-described structure.

The present invention also includes an embodiment constructed by arbitrarily combining the above embodiments and modifications thereof.

The present invention can be realized not only as such an electric storage element 10 but also as an electrode body 400 and an insulating sheet 500.

Industrial applicability

The present invention can be applied to an electric storage element such as a lithium ion secondary battery.

Description of the symbols

10. 11 an electric storage element;

130 a positive electrode collector;

131 terminal side arrangement parts;

132 electrode body side arrangement portion;

140 a negative electrode current collector;

141 terminal side arrangement parts;

142 an electrode body-side arrangement portion;

a 400 electrode body;

401 a main body portion;

410. 420 a connecting part;

430 a positive plate;

431. 441 connection;

440 a negative plate;

500. 501 insulating sheet material;

510. 510a, 510b sheet side face portions;

520. 520a, 520b, 520c sheet extension setting parts;

521. 521a and 521b openings;

600 baffle plates;

700 of the joint.