WO2022196460A1 - Electrochemical cell - Google Patents

Abstract

An electrochemical cell according to the present invention is characterized by comprising an exterior body that has at least one flat surface, that has a through-hole formed inward of a peripheral edge part of the flat surface, and that has an electrode plate for closing the through-hole via a first resin film fused to a peripheral edge part of the through-hole, and is characterized in that: the first resin film has an extending part extending outward of the peripheral edge of the electrode plate; the first resin film is fused to the electrode plate; and a second resin film is fixed to the peripheral edge part of the electrode plate and the extending part.

Description

electrochemical cell

The present invention relates to electrochemical cells. This application claims priority based on Japanese Patent Application No. 2021-042750 filed in Japan on March 16, 2021, the content of which is incorporated herein.

Conventionally, electrochemical cells such as lithium ion secondary batteries and electrochemical capacitors have been widely used as power sources for small devices such as smartphones, wearable devices, and hearing aids.
In this type of electrochemical cell, from the viewpoint of increasing the battery capacity and charging current and discharging current, it is necessary to increase the area of the electrodes facing each other in the electrochemical cell as much as possible. As a structure of an electrochemical cell, a structure is known in which a pair of strip-shaped positive electrode and negative electrode are wound with a separator interposed therebetween, or folded and housed in a case, and an electrolytic solution is enclosed in the case.

For example, in Patent Document 1 below, an electrode body composed of a positive electrode and a negative electrode, and an exterior body composed of a first laminate member and a second laminate member are provided. describes a battery (electrochemical cell) having an outer peripheral wall formed by bending the outer peripheral portion of the second laminate member and the outer peripheral portion of the second laminate member.

The exterior body is made of a laminated laminate member of a metal foil and a resin layer, and is sealed by bending and fusing the outer peripheral walls of the first and second laminate members, so that the capacity per volume is reduced. You can provide a battery that can be upgraded.

JP 2018-085214 A

As shown in FIGS. 12 and 13, the battery 100 described in Patent Literature 1 is configured by combining a first container 101 and a second container 102 in the form of thin cylindrical containers each made of a laminated member of metal and resin. ing. The outer peripheral wall 104 of the second container 102 is bent along the entire periphery to have a U-shaped cross section, and the cylindrical outer wall 103 of the first container 101 surrounds the outer peripheral side of the U-shaped bent portion. is provided. Then, the overlapping portions of the outer peripheral wall 103 and the outer peripheral wall 104 are heat-sealed.
A disk-shaped negative electrode plate 105 is arranged inside the through hole in the center of the bottom plate of the first container 101 , and a disk-shaped protective plate 106 is arranged inside the through hole in the center of the top plate of the second container 102 . A positive electrode plate 109 is provided. A negative electrode sealant ring 107 is arranged adjacent to the negative electrode plate 105 , and a positive electrode sealant ring 108 is arranged adjacent to the positive electrode plate 109 .

An electrode body 110 is housed between the sealant rings 107 and 108 inside the first container 101 and the second container 102 .
The electrode body 110 is configured by winding or folding and stacking strip-shaped negative and positive bodies. For example, as shown in FIG. 112 are arranged.

In the battery 100 configured as shown in FIGS. 12 and 13, the negative electrode plate 105 is heat-sealed inside the through hole of the first container 101 via the negative sealant ring 107, and the positive electrode plate 109 is heat-sealed with the positive sealant. It is heat-sealed to the inside of the through hole of the second container 102 via the ring 108 .
The fused portion of the sealant rings 107 and 108 is a boundary between the inside and the outside of the battery 100, so a highly reliable sealing structure is required. There is a problem that only the sealing structure lacks reliability.
For example, in a configuration in which an electrolytic solution or the like is enclosed inside the battery 100, if a problem occurs in the heat-sealed portion described above, it may lead to leakage of the electrolytic solution.
Also in the sealing structure of a general electrochemical cell, the reliability of the heat-sealed portion is considered to be important in a structure in which the periphery of the electrode terminal is sealed by heat-sealing a resin seal.

The present invention has been devised in view of the conventional circumstances as described above. An object of the present invention is to provide an electrochemical cell in which the reliability of the sealing structure is improved.

(1) The electrochemical cell according to the present invention has at least one flat surface, a through hole is formed inside the peripheral edge of the flat surface, and the first resin film is fused to the peripheral edge of the through hole. an exterior body having an electrode plate that closes the through hole through an outer body; the first resin film has an extension portion extending outward from the peripheral edge of the electrode plate; A second resin film is fixed to the extending portion and the peripheral edge portion of the electrode plate by fusion bonding to the plate.

(2) In the electrochemical cell according to the present invention, a configuration may be employed in which the first resin film and the second resin film are fused together on the outside of the peripheral edge of the electrode plate.

With the structure described above, the electrode plate can be sandwiched between the first resin film and the second resin film, and the electrode plate sandwiched between the first resin film and the second resin film can be transparent to the exterior body. It can be placed outside or inside the hole. A sealing structure around the electrode plates can be completed by fusing the first resin film to the outer surface or the inner surface of the exterior body.
In the case of the above-mentioned structure, the structure in which the electrode plate on the positive electrode side or the negative electrode side is sandwiched between the first resin film and the second resin film is mounted inside or outside the container-like exterior body and fused. An assembly process can be adopted.
The work of adhering the first resin film and the second resin film to the positive electrode side or the negative electrode plate can be performed separately from the operation of inserting them into the container-shaped exterior body. Therefore, by attaching the positive electrode plate or the negative electrode plate to the outer package together with the first resin film and the second resin film, the positive electrode plate or the negative electrode plate can be accurately positioned in the outer package. and can be accommodated.

After accurately positioning the electrode plate on the positive electrode side or the negative electrode side and the first resin film and the second resin film, the whole including both resin films is housed in the exterior body, so that the positive electrode side or the negative electrode side with respect to the exterior body The electrode plate on the negative electrode side can be accurately positioned and accommodated.
In addition, when housing the positive electrode plate or the negative electrode plate in the outer package, the first resin film and the second resin film serve as cushioning materials, so that the positive electrode plate or the negative electrode plate comes into contact with the outer package. the risk of damaging the
Since the positive or negative electrode plate can be positioned easily and accurately, the positive electrode plate or the negative electrode plate can be made as large as possible within the range that can be accommodated in the exterior body, which is a desirable structure for an electrochemical cell. can be
In addition, since the structure is such that the first resin film and the second resin film are fused to the electrode plate, the structural stability of the fused portion is improved, and the electrode plate on the positive electrode side or the negative electrode side is connected to the first resin film. It is possible to provide a structure in which the electrodes are protected from both sides by the second resin film and the surroundings of the electrode plates in the exterior body are well sealed.

(3) In the electrochemical cell according to the present invention, a recess is formed in the plane, and the through holes formed in the bottom surface of the recess are arranged on either side of the bottom surface. A configuration closed by a plate can be adopted.

When the electrode plate is provided in the concave portion provided on the plane of the outer package, after the electrode plate on the positive electrode side or the negative electrode side and the first resin film and the second resin film are accurately positioned, the first resin film and the second resin film are positioned. By accommodating the electrode plate including the resin film of No. 2 in the concave portion, the electrode plate on the positive electrode side or the negative electrode side can be accurately positioned and accommodated in the concave portion of the outer package and fused.

(4) In the electrochemical cell according to the present invention, at least one of a positive electrode and a negative electrode provided in an electrode body that is housed in the exterior body and electrically connected to the electrode plate is connected to the electrode plate. configuration can be adopted.

The positive electrode side of the electrode body and the electrode plate can be connected through the through hole provided in the resin film on the positive electrode side.
The negative electrode side of the electrode body and the electrode plate can be connected through the through hole provided in the resin film on the negative electrode side.

(5) In the electrochemical cell according to the present invention, the exterior body may be composed of a metal can or a laminate film.
The exterior body may employ either a configuration made of a metal can or a configuration made of a laminate film. When a laminate film is used, if there is friction or contact with the electrode plate, there is a risk of damage to the laminate film. there is no risk of damaging the

(6) In the electrochemical cell according to the present invention, the resin film has a laminated structure including a fusion layer on the electrode plate side and a base layer on the opposite side, and the fusion layer is lower than the base layer. A configuration made of resin having a melting point can be employed.

If the electrode plate side of the resin film is a fusion layer made of a resin with a low melting point, it is possible to obtain a good fusion structure in which poor adhesion does not occur when the resin film is fused to the electrode plate.
Further, if the base layer has a melting point higher than the heater temperature for fusing the resin film to the electrode plate, the resin film will not adhere to the heater when fusing.
Therefore, the resin film on the positive electrode side can provide a fused structure with good adhesion to the positive electrode plate, and the resin film on the negative electrode side can provide good adhesion to the negative electrode plate. It is possible to provide a fused structure with In addition, when the heater is separated after pressurization and heating with the heater to fuse these resin films, problems such as the resin film adhering to the heater side and peeling of the fused portion do not occur. Therefore, an electrochemical cell having a highly reliable fused structure can be provided.

(7) In the electrochemical cell according to the present invention, a configuration in which the first resin film and the second resin film are made of the same material can be adopted.

The first resin film and the second resin film provided on both sides of the electrode plate may be made of the same material. structure can be provided.

(8) In the electrochemical cell according to the present invention, the exterior body includes a case having a bottom portion and a side portion, and a cover plate that seals an opening of the case, and the flat surface is provided on the bottom portion. configuration can be adopted.

A configuration can be employed in which a flat surface is provided on the bottom of the exterior body, a through hole is formed in this flat surface, and an electrode plate that closes the through hole is provided in this flat surface. In this configuration, an electrode plate sandwiched between the first resin film and the second resin film can be provided on the bottom side of the exterior body.
With the structure described above, an electrochemical cell having an excellent sealing structure around the electrode plates can be provided in the structure in which the electrode plates are provided on the bottom side of the outer package.

In the case of the electrochemical cell according to the present invention, an assembling process can be adopted in which the structure in which the electrode plate is sandwiched between the first resin film and the second resin film is housed in the exterior body and fused. Alternatively, after the first resin film is mounted inside or outside the through-hole of the exterior body, the electrode plate with the second resin film fused is inserted along one of the resin films and fused. It is possible to adopt an assembly process of
These processes are particularly effective in structures where the outer diameter of the electrochemical cell is small and accurate positioning of small electrode plates is required.
Since the operation of bringing the resin film into close contact with the electrode plate can be performed separately from the operation of inserting the resin film into the outer package, it is possible to easily align the resin film and the electrode plate. In addition, since both the resin film and the electrode plate can be fused to the exterior body in a flat state, the reliability of the fused portions is improved.

Further, after the electrode plate and the resin film are accurately positioned, the entire assembly is housed in the exterior body, so that the electrode plate can be accurately positioned and housed with respect to the exterior body. Furthermore, since the first resin film and the second resin film serve as cushioning materials when the electrode plates are housed in the exterior body, there is no possibility that the electrode plates will hit the exterior body and damage the exterior body. This is effective when the exterior body has a structure that is easily damaged, such as a laminated film.
Moreover, since both surfaces of the electrode plate are sandwiched between the resin films, a structure in which the electrode plate is protected from both sides can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a drawing for explaining the electrochemical cell of the first embodiment according to the present invention, FIG. 1A shows a top-opening metal container and a cover plate, and an electrode plate and a resin film to be attached to the upper surface side of the cover plate. 1 is an exploded cross-sectional view of FIG. FIG. 1B is an exploded cross-sectional view showing a state in which a resin film is fused to a cover plate; FIG. 1C is a cross-sectional view showing an electrochemical cell constructed by welding a cover plate to a metal container; FIG. 2A is a drawing for explaining an electrochemical cell of a second embodiment according to the present invention, FIG. 2A shows a top-opening metal container and a cover plate, and an electrode plate and a resin film to be attached to the lower surface side of the cover plate. 1 is an exploded cross-sectional view of FIG. FIG. 2B is an exploded cross-sectional view showing a state in which the resin film is fused to the cover plate; FIG. 2C is a cross-sectional view showing an electrochemical cell constructed by welding a cover plate to a metal container; FIG. 3A is a drawing for explaining the electrochemical cell of the third embodiment according to the present invention, and FIG. FIG. 3 is an exploded sectional view showing an electrode plate and a resin film; FIG. 3B is an exploded cross-sectional view showing a state in which the resin film is fused to the concave portion of the cover plate; FIG. 3C is a cross-sectional view showing an electrochemical cell constructed by welding a cover plate to a metal container; FIG. 4A is a drawing for explaining an electrochemical cell of a fourth embodiment according to the present invention, and FIG. 4A shows a lid plate with a top opening type metal container and a bottom side recess, and a lid plate to be attached to the top side of the lid plate. FIG. 3 is an exploded sectional view showing an electrode plate and a resin film; FIG. 4B is an exploded cross-sectional view showing a state in which the resin film is fused to the concave portion of the cover plate; FIG. 4C is a cross-sectional view showing an electrochemical cell constructed by welding a cover plate to a metal container; FIG. 4 is a perspective view showing an example of an electrode body housed in any one of the electrochemical cells; FIG. 6 is a plan view showing a state in which an electrode plate is attached to the electrode body shown in FIG. 5; FIG. 4 is a cross-sectional view showing a state in which one electrode plate of an electrode body having electrode plates is housed in an exterior body and fused. FIG. 4 is an exploded perspective view showing an electrode plate and resin films arranged on both sides thereof; FIG. 4 is a perspective view showing an example of an electrode body with a folding structure; FIG. 3 is a cross-sectional view showing an example structure in which an electrode plate sandwiched by a resin film is attached to the bottom of an exterior body made of a metal can. FIG. 3 is a cross-sectional view showing a structure in which an electrode plate sandwiched by a resin film is attached to an exterior body made of a metal can and having a concave portion at the bottom. 1 is a perspective view showing an example of an electrochemical cell provided with an outer package made of a laminate film; FIG. FIG. 13 is a perspective view of a part of the electrochemical cell shown in FIG. 12 in cross section; FIG. 5 is a cross-sectional view showing an electrochemical cell of a fifth embodiment according to the present invention; FIG. 6 is a cross-sectional view showing an electrochemical cell of a sixth embodiment according to the present invention; FIG. 7 is a cross-sectional view showing an electrochemical cell of a seventh embodiment according to the invention; FIG. 11 is a cross-sectional view showing an electrochemical cell of an eighth embodiment according to the present invention; FIG. 11 is a cross-sectional view showing an electrochemical cell of a ninth embodiment according to the present invention; FIG. 10 is a cross-sectional view showing an electrochemical cell of a tenth embodiment according to the present invention;

An embodiment of an electrode according to the present invention will be described below with reference to the drawings. In the following embodiments, as an example of an electrochemical cell, a coin-type lithium ion secondary battery (hereinafter sometimes simply referred to as "battery") will be cited, and electrodes mounted in this battery will be described.
Note that in the drawings used for the following description, the scale of each member may be appropriately changed in order to make each member recognizable in size.

<First Embodiment>
1A to 1C are diagrams for explaining the first embodiment of the electrochemical cell according to the present invention, and the electrochemical cell (battery) 1 of the first embodiment has the configuration shown in FIG. 1C in plan view. It is a circular button type battery. This battery 1 includes a container-shaped exterior body 2 made of a metal can and an electrode body 3 housed inside the exterior body 2 .
Although not shown in FIG. 1, the interior of the exterior body 2 is filled with an electrolytic solution. As this electrolytic solution, an electrolytic solution obtained by dissolving a supporting salt in a non-aqueous solvent is preferably used.

The exterior body 2 comprises a lower container 2A having an open top and having a bottom wall 2a and a side wall (peripheral wall) 2b, and a cover plate fixed to the upper part of the side wall by a joining method such as welding so as to close the opening of the lower container 2A. 2B. Since the exterior body 2 is a button type, it has an upper surface (flat surface), a lower surface (flat surface), and side surfaces (peripheral surface). The cover plate 2A has a flat plate shape, and an electrode plate 5 is attached to the flat surface thereof as described later.
A through hole 2d having an inner diameter about a fraction of the outer diameter of the cover plate 2B is formed in the central portion of the cover plate 2B, and a disk-shaped electrode plate is formed so as to cover the upper opening side of the through hole 2d. 5 is installed.
A first ring-shaped resin film 7 and a second ring-shaped resin film 6 are attached to the electrode plate 5 so as to cover the periphery of the lower surface and the periphery of the upper surface. Through holes 6a and 7b having inner diameters about a fraction of their outer diameters are formed in the central portions of the resin films 6 and 7, respectively. The outer diameters of the resin films 6 and 7 are slightly larger than the outer diameter of the electrode plate 5 and the inner diameters of the resin films 6 and 7 are slightly smaller than the outer diameter of the electrode plate 5 .

The electrode plate 5 is made of a highly corrosion-resistant stainless steel plate such as SUS316. Moreover, it is preferable that a Ni plating layer is formed on the upper surface side (external contact side) of the electrode plate 5 .
By providing the Ni plating layer, it is possible to prevent corrosion of the electrode plate 5, which may occur due to contact with the electrolyte. Alternatively, the Ni plating layer provided on the upper surface side of the electrode plate 5 may be omitted, and instead of the Ni plating layer, an external electrode plate made of a Ni plate may be attached by a joining method such as welding.

The resin films 6 and 7 are fused to the electrode plate 5 so as to sandwich the electrode plate 5 from both sides in the thickness direction with their center positions aligned with the center position of the electrode plate 5 . Therefore, the central portion of the electrode plate 5 is not covered with the resin films 6 and 7, the central portion of the electrode plate 5 is exposed to the outside of the battery 1, and the peripheral portion of the electrode plate 5 is covered with the resin films 6 and 7. is covered with a predetermined width by the outer peripheral portion of the The outer peripheral edge sides of the resin films 6 and 7 protrude outward from the outer peripheral edge of the electrode plate 5 with a predetermined width, and the outer peripheral edge portions of the resin films 6 and 7 located on the outer side of the electrode plate 5 (Extension portions) are aligned with each other on the outside of the electrode plate 5 and integrated with each other by thermal fusion to form fused portions 6b and 7b. The first resin film 7 is fused to the peripheral edge of the lower surface of the electrode plate 5 , and the second resin film 6 is fused to the peripheral edge of the upper surface of the electrode plate 5 . The lower surface side of the first resin film 7 is fused to the periphery of the through hole of the cover plate 2B.
The resin films 6 and 7 may be fused by other fusion means (welding means) such as ultrasonic welding, laser welding, and high-frequency welding, in addition to thermal fusion.

The electrode plate 5 is attached to the lid plate 2B by fusion bonding so as to be positioned outside the through hole 2d on the exterior side of the exterior body 2. In addition, in the configuration shown in FIG. 1C, the first resin film 7 is interposed between the electrode plate 5 and the cover plate 2B, so the first resin film 7 can be called a sealant film. Since the second resin film 6 covers the outer surface of the electrode plate 5, it can be called a resin cover.

The second resin film 6 has, for example, a two-layer laminated structure consisting of a fusion layer 6A and a base layer 6B supporting the fusion layer 6A, as will be described with reference to FIG. 8 in another embodiment described later. .
The first resin film 7 includes, for example, a fusion layer 7A, a base layer 7B that supports the fusion layer 7A, and a surface opposite to the base layer 7B, as will be described with reference to FIG. 8 in another embodiment described later. A three-layer laminate structure consisting of a fusion layer 7C that is fused together can be employed.
The base layers 6B and 7B of the resin film are made of high-melting resin such as PET (polyethylene terephthalate), PPS (polyphenylene sulfide) and nylon. ) or a low melting point resin such as a copolymer. By forming the fusion layers 6A, 7A, and 7C of the resin films 6 and 7 with a resin having a lower melting point than the base layers 6B and 7B, bonding by heat fusion, which will be described later, is ensured.
The high melting point resin referred to here means a resin having a higher melting point than the general heat-sealing temperature (150 to 200° C.), and the low melting point resin is a resin having a lower melting point than the high melting point resin. It means a resin with a melting point lower than the general heat-sealing temperature.

In order to manufacture the electrochemical cell 1 shown in FIG. 1C, first, as shown in FIG. The first resin film 7, the electrode plate 5, and the second resin film 6 are stacked one on top of the other while aligning their centers. When the electrode plate 5 is sandwiched between the resin films 6 and 7, the resin films 6 and 7 on the fusion layer 6A side and the fusion layer 7A side are arranged on the electrode plate 5 side, respectively. Further, the fusion layer 7C of the second resin film 7 is arranged on the cover plate 2B side.
The cover plate 2B and the first resin film 7, the electrode plate 5, and the second resin film 6 which are arranged so as to overlap thereabove are sandwiched by a heating jig (heater) for welding, and each resin film 6 is heated and pressurized. , 7 on the side of the electrode plate 5 (bonding layers 6A and 7A) and the portion of the resin film 7 on the side of the cover plate 2B (bonding layer 7C) are melted. After cooling after this melting process, the resin films 6 and 7 can be fused to the electrode plate 5 and the first resin film 7 can be fused to the cover plate 2B as shown in FIG. 1B.
At the same time, the outer peripheral edges (extending portions) of the resin films 6 and 7 protruding outside the electrode plate 5 are heat-sealed and integrated to form the fused portions 6b and 7b.

Separately from the fusion bonding process of the resin films 6 and 7, the electrode assembly 3 may be housed inside the lower container 2A as shown in FIG. of two electrode tabs (a positive electrode tab and a negative electrode tab) provided on the electrode body 3, one electrode tab to be connected to the lower container 2A side is placed in the lower container The other electrode tab is joined to the inner surface of 2A by a joining method such as welding, and the other electrode tab is joined to the bottom surface side of the electrode plate 5 by a joining method such as welding. After the electrode tabs of the electrode body 3 are joined, the electrolytic solution is injected into the lower container 2A, and after the electrolytic solution is injected, the peripheral portion of the cover plate 2B is joined to the upper side wall of the lower container 2A by a joining method such as welding. . A laser welding method, a resistance welding method, or the like can be appropriately used for the welding described above.
Through the above processes, the electrochemical cell 1 having the structure shown in FIG. 1C can be obtained.

In the electrochemical cell 1 obtained by the above-described method, the electrode plate 5 sandwiched between the resin films 6 and 7 is arranged outside the through hole 2d of the cover plate 2B (outside the container-like exterior body 2), The resin films 6 and 7 are fused to the outer surface side of the cover plate 2B, the outer peripheral edges (extending portions) of the resin films 6 and 7 are fused to each other, and the first resin film 7 is fused to the electrode plate 5. A sealing structure around the electrode plate 5 can be completed by attaching them.
With this structure, it is possible to adopt an assembling process of fusing (welding) the structure in which the electrode plate 5 is sandwiched between the resin films 6 and 7 to the cover plate 2B.
Further, the operation of attaching the resin films 6 and 7 to the electrode plate 5 and the cover plate 2B can be performed separately from the operation of inserting the electrode assembly 3 into the lower container 2A. At the same time, the electrode plate 5 can be accurately positioned.

By accurately positioning the electrode plate 5 and the resin films 6 and 7 and fusing the resin films 6 and 7 to the cover plate 2B, the electrode plate 5 is precisely positioned and then fused to the cover plate 2B. be able to. In the case of fusion bonding, the fusion layers 6A, 7A, and 7C having a low melting point are mainly melted to fuse the resin film 6, the electrode plate 5, the resin film 7, and the cover plate 2B. Reliability can also be made sufficiently high.
Moreover, when the electrode plate 5 is attached to the cover plate 2B, the resin films 6 and 7 serve as cushioning materials to protect the electrode plate 5 and the cover plate 2B. Furthermore, since the resin films 6 and 7 are fused to the electrode plate 5, the structural stability of the fused portion is improved, and the electrode plate 5 is protected from both sides by the resin films 6 and 7. can.

<Second embodiment>
2A to 2C are diagrams for explaining a second embodiment of an electrochemical cell according to the present invention. The electrochemical cell 10 of the second embodiment is a circular button-shaped battery in plan view. In this battery 10, the structure including an outer body 2 made of a metal container and an electrode body 3 housed inside the outer body 2 is the same as that of the first embodiment.
Although not shown in FIG. 2, the inside of the exterior body 2 is filled with an electrolytic solution. As this electrolytic solution, an electrolytic solution obtained by dissolving a supporting salt in a non-aqueous solvent is preferably used.

The electrochemical cell 10 of the second embodiment differs from the electrochemical cell 1 of the first embodiment in that the electrode plate 5 is sandwiched between the resin films 6 and 7 on the lower surface side of the cover plate 2B. is attached to the structure. The electrode plate 5 is attached by fusing the first resin film 7 to the lower surface side of the cover plate 2B.
In the second embodiment, the structure of the lower container 2A and the lid plate 2B, and the structure of the electrode plate 5 and the resin films 6 and 7 are the same as in the first embodiment, but the electrode plate 5 is fixed to the lower surface side of the lid plate 2B. differ only in their configuration. Other configurations are the same.
Therefore, the electrode plate 5 is attached to the lid plate 2B by fusion bonding so as to be located inside the outer package 2 and inside the through hole 2d. Since the lid plate 2B is flat, it has an upper surface (flat surface) and a lower surface (flat surface). In this embodiment, the electrode plate 5 is attached to the lower surface (flat surface).

In order to manufacture the electrochemical cell 1 shown in FIG. 2C, first, as shown in FIG. The second resin film 6, the electrode plate 5, and the first resin film 7 are stacked one on top of the other while their centers are aligned. The cover plate 2B and the first resin film 7, the electrode plate 5 and the second resin film 6 stacked thereunder are sandwiched by a heating jig for welding, and the electrode plates of the films 6 and 7 are heated and pressurized. The portions on the 5 side (the fusion layer 6A and the fusion layer 7A) are melted. Further, when the portion (fusion layer 7C) of the first resin film 7 on the side of the lid plate 2B is melted and then cooled, the resin films 6 and 7 are fused to the electrode plate 5, and as shown in FIG. 1 resin film 7 can be fused to the cover plate 2B.
At the same time, the outer peripheral edge portions (extending portions) of the resin films 6 and 7 protruding outside the electrode plate 5 are fused together to form fused portions 6b and 7b.

Separately from the fusion bonding of the resin films 6 and 7 described above, the electrode body 3 may be housed inside the lower container 2A as shown in FIG. The electrode body 3 is accommodated inside the lower container 2A, and one electrode tab to be connected to the lower container 2A side of the two electrode tabs (a positive electrode tab and a negative electrode tab) not shown provided on the electrode body is connected to the lower container 2A. The other electrode tab is joined to the bottom surface of the electrode plate 5 by welding or the like. After the electrode tabs of the electrode body 3 are joined, the electrolytic solution is injected into the lower container 2A, and after the electrolytic solution is injected, the peripheral portion of the cover plate 2B is joined to the upper side wall of the lower container 2A by a joining method such as welding. . A laser welding method, a resistance welding method, or the like can be appropriately used for the welding described above.

Through the above processes, the electrochemical cell 10 having the structure shown in FIG. 2C can be obtained.
Even with the electrochemical cell 10 having the configuration shown in FIG. 2C, it is possible to obtain effects equivalent to those of the electrochemical cell 1 of the first embodiment.

<Third Embodiment>
3A to 3C are diagrams for explaining a third embodiment of an electrochemical cell according to the present invention, and the electrochemical cell 15 of the third embodiment is a circular button-shaped battery in plan view. In this battery 15, the structure including an outer body 2 made of a metal container and an electrode body 3 housed inside the outer body 2 is the same as that of the first embodiment.
Although not shown in FIG. 3, the interior of the exterior body 2 is filled with an electrolytic solution. As this electrolytic solution, an electrolytic solution obtained by dissolving a supporting salt in a non-aqueous solvent is preferably used.

The configuration of the third embodiment differs from the configuration of the first embodiment in the configuration of the cover plate. Unlike the configuration in which the cover plate 2B of the first embodiment is flat, the configuration of the third embodiment is different in that the cover plate 2D has a concave portion 2e formed in its central portion. The recessed portion 2e is formed in a ring shape in plan view so as to be one step lower than the outer peripheral edge portion of the cover plate 2D. Therefore, a flat surface is formed on the upper surface side of the concave portion 2e of the cover plate 2D.
An electrode plate 5 sandwiched between resin films 6 and 7 is attached to the upper surface of the concave portion 2e. The inner peripheral side of the lower surface of the second resin film 6 is fused to the outer peripheral portion of the upper surface of the electrode plate 5, and the outer peripheral edge portions (extending portions) of the resin films 6 and 7 projecting outward from the outer peripheral edge of the electrode plate 5 ) are fused together to form fused portions 6b and 7b, the inner peripheral side of the upper surface of the first resin film 7 is fused to the outer peripheral side of the lower surface of the electrode plate 5, and the lower surface of the first resin film 7 is fused. The outer peripheral side is fused to the upper surface side of the concave portion 2e.
Therefore, the electrode plate 5 is attached to the concave portion 2e of the cover plate 2B by fusion bonding so as to be located on the outer side of the exterior body 2 and outside the through hole 2d.

Also for the structure of the third embodiment, the first resin film 7, the electrode plate 5, and the second resin film 6 are aligned as shown in FIG. The electrochemical cell 15 shown in FIG. 3C can be obtained by stacking them, fusing them as shown in FIG. 3B, and welding the cover plate 2D to the upper side wall of the lower container 2A.
Even with the electrochemical cell 15 having the configuration shown in FIG. 3C, it is possible to obtain effects equivalent to those of the electrochemical cell 1 of the first embodiment.

<Fourth Embodiment>
4A to 4C are diagrams for explaining a fourth embodiment of an electrochemical cell according to the present invention. An electrochemical cell 20 of the fourth embodiment is a circular button-shaped battery in plan view. In this battery 20, the structure including an outer body 2 made of a metal container and an electrode body 3 housed inside the outer body 2 is the same as that of the first embodiment.
Although not shown in FIG. 4, the interior of the exterior body 2 is filled with an electrolytic solution. As this electrolytic solution, an electrolytic solution obtained by dissolving a supporting salt in a non-aqueous solvent is preferably used.

The electrochemical cell 20 of the fourth embodiment differs from the electrochemical cell 15 of the third embodiment in that a convex portion 2f is formed instead of the concave portion 2e in the central portion of the cover plate 2E. is different. The convex portion 2f is formed in a ring shape in plan view so as to be one step higher than the outer peripheral edge portion of the cover plate 2E. Therefore, a flat surface is formed on the lower surface side of the convex portion 2f of the cover plate 2E.
An electrode plate 5 sandwiched between resin films 6 and 7 is attached to the lower surface of the cover plate 2E. The electrode plate 5 is attached by fusing the resin films 6 and 7 to the lower surface side of the cover plate 2E.
In the fourth embodiment, the structure of the lower container 2A and the structure of the electrode plate 5, the second resin film 6 and the first resin film 7 are the same as those in the third embodiment, but the cover plate 2E has a convex portion 2f. The only difference is that the electrode plate 5 is fixed to the lower surface of the cover plate 2E. Other configurations are the same.
The electrode plate 5 of the fourth embodiment is mounted on the convex portion 2f of the cover plate 2B by fusion bonding so as to be located inside the outer package 2 and inside the through hole 2d.

Also for the structure of the fourth embodiment, the second resin film 6, the electrode plate 5, and the first resin film 7 are aligned as shown in FIG. The electrochemical cell 20 shown in FIG. 4C can be obtained by stacking them on top of each other, fusing them to the cover plate 2E as shown in FIG. 4B, and welding the cover plate 2E to the upper part of the side wall of the lower container 2A.
Even with the electrochemical cell 20 having the configuration shown in FIG. 4C, it is possible to obtain effects equivalent to those of the electrochemical cell 1 of the third embodiment.

In the electrochemical cells 1, 10, 15, and 20 of the first to fourth embodiments described so far, detailed description of the configuration of the electrode body 3 has been omitted. A configuration as described in 1 can be adopted.

<Electrode body>
FIG. 5 is a perspective view showing an electrode body 3 as one embodiment, and this electrode body 3 includes a negative electrode body 30 coated with a negative electrode separator layer 36 and a positive electrode body 40 coated with a positive electrode separator layer 46. consists of
The electrode body 3 is an electrode body in which a negative electrode body 30 and a positive electrode body 40 are wound so as to be alternately laminated. Specifically, the electrode body 3 is formed by stacking the negative electrode body 30 and the positive electrode body 40 with the negative electrode side separator layer 36 interposed therebetween and winding them in a flat shape. A negative electrode tab 35 is provided on the negative electrode body 30 , and the positive electrode tab 45 of the positive electrode body 40 is connected to, for example, the electrode plate 5 described above.
In the present embodiment, the structure of the portion where the negative electrode tab 35 is connected to the lower container 2A and the structure of the portion where the positive electrode tab 45 is connected to the electrode plate 5 are folding structures, which will be described later. I will explain later. Note that the electrode body 3 having a wound structure is merely an example, and other structures may be adopted, and an example of the electrode body having another structure will be described later.

The negative electrode-side separator layer 36 is formed so as to cover the entire negative electrode body 30 except for the negative electrode tab 35 and the peripheral portion on the base end side thereof. The positive electrode side separator layer 46 is formed so as to cover the entire positive electrode body 40 except for the positive electrode tab 45 and its base end side peripheral portion.
Therefore, the separator layers 36 and 46 are arranged around and between the layers of the negative electrode body 30 and the positive electrode body 40 in a state in which the negative electrode body 30 and the positive electrode body 40 are wound, and the negative electrode body 30 and the positive electrode body 40 are insulated from each other. separated.

In FIG. 5, only the positions of the separator layers 36 and 46 are shown, ignoring the layer thickness. The positive electrode separator layer 46 is arranged to cover the positive electrode body 40 so as to be interposed between the negative electrode body 30 and the positive electrode body 40 and so that the negative electrode side separator layer 36 covers the negative electrode body 30 .
Hereinafter, the direction in which the negative electrode body 30 and the positive electrode body 40 are wound and stacked is referred to as a stacking direction. Note that winding means winding around a specific winding center axis.

The negative electrode body 30 is a sheet-like member including a foil-shaped negative electrode current collector made of a metal material and a negative electrode active material layer coated on one or both sides of the negative electrode current collector. The negative electrode current collector is made of, for example, metal foil such as copper or nickel. The thickness of the metal foil is, for example, about several μm. The negative electrode active material is, for example, a single substance or a mixture of silicon, silicon oxide, graphite, hard carbon, lithium titanate, and the like. The negative electrode current collector is composed of a plurality of circular negative electrode bodies and a band-shaped connection portion that connects adjacent negative electrode bodies, and a negative electrode tab extends from the outer peripheral portion of the negative electrode current collector at one end in the arrangement direction.

As materials for forming the negative electrode active material layer, in addition to the negative electrode active material, a conductive agent (eg, acetylene black), a binder (eg, dispersion of polyvinylidene fluoride, styrene-butadiene rubber (SBR), etc.), a thickener ( For example, carboxymethyl cellulose (CMC), etc.) and a solvent (eg, any solvent such as water, N-methylpyrrolidone, etc.) can be mixed to prepare a negative electrode slurry. A coating liquid containing constituent materials for forming a negative electrode active material layer can be referred to as a “negative electrode slurry”. A negative electrode active material layer can be formed by applying this negative electrode slurry to a negative electrode current collector and drying it.

The positive electrode body 40 is a sheet-like member including a foil-shaped positive electrode current collector made of a metal material and a positive electrode active material layer coated on one or both sides of the positive electrode current collector. be. The positive electrode current collector is made of, for example, metal foil such as aluminum or stainless steel. The thickness of the metal foil is, for example, about ten and several μm. The positive electrode active material is, for example, a composite oxide containing lithium and a transition metal, such as lithium cobaltate, lithium titanate, and lithium manganate. The positive electrode current collector is composed of a plurality of circular positive electrode bodies and a band-like connecting portion that connects adjacent positive electrode bodies, and a positive electrode tab extends from the outer peripheral portion of the positive electrode current collector at one end in the arrangement direction.

As materials for forming the positive electrode active material layer, in addition to the positive electrode active material described above, a conductive aid (eg, acetylene black, etc.), a binder (eg, polyvinylidene fluoride, etc.), a solvent (eg, any solvent such as N-methylpyrrolidone, etc.) ) can be mixed to prepare a positive electrode slurry. A coating liquid containing constituent materials for forming a positive electrode active material layer can be referred to as a “positive electrode slurry”. The positive electrode active material layer can be formed by applying the positive electrode slurry to the positive electrode side current collector and drying it.

The separator layers 36 and 46 are, for example, resin layers having lithium ion conductivity. The separator layers 36 and 46 are formed of, for example, a polyolefin resin porous film, a glass nonwoven fabric, a resin nonwoven fabric, a laminate of cellulose fibers, or the like. Since the separator layers 36 and 46 are sufficient to separate the positive electrode body 40 and the negative electrode body 30, one of them may be omitted.

As shown in FIG. 3, the electrode bodies 3 of this embodiment are formed in a shape corresponding to the shape of the sealed space in the exterior body 2 so as to be arranged in the exterior body 2 at high density. That is, the electrode body 3 is formed in a circular shape when viewed from the stacking direction.
The negative electrode body 30 has a configuration in which a plurality of circular negative electrode bodies are connected via a connecting portion so as to be arranged in a strip shape or the like, and the positive electrode body 40 has a configuration in which a plurality of circular positive electrode bodies are arranged in a strip shape or the like. It has the structure connected through the connection part so that it may carry out. Therefore, the electrode body 3 shown in FIG. 5 is configured by alternately stacking or winding the circular negative electrode current collector of the negative electrode body 30 and the circular positive electrode current collector of the positive electrode body 40 .

In the case of the electrode body 3 shown in FIG. 5, it can be attached to the exterior body 2 as described below based on FIGS.
FIG. 6 is a plan view showing a state in which the electrode body 3 is arranged with the positive electrode tab 45 extended leftward and the negative electrode tab 35 extended rightward. The positive electrode plate 5 is ultrasonically welded to the tip surface side (front side) of the positive electrode tab 45 .
Before welding, ring-shaped resin films 6 and 7 are fused around the part where the tip of the positive electrode tab 45 is to be welded on one side (rear side) of the electrode plate 5 shown in FIG.

Regarding the ring-shaped resin films 6 and 7, the structure shown in FIG. 8 can be adopted. As described above, in the configuration shown in FIG. 8, the first resin film 7 having a three-layer structure is fused to the lower surface of the electrode plate 5, and the second resin film having a two-layer structure is attached to the upper surface of the electrode plate. A film 6 is fused.
The surface of the second resin film 6 facing the electrode plate 5 is a fusion layer 6A, and the surface of the first resin film 7 facing the electrode plate 5 is a fusion layer 7A.
By sandwiching and fusing the electrode plate 5 between the resin films 6 and 7, the fusing layer 6A and the fusing layer 7A can be fused to the electrode plate 5, and the fusing layer 6A projecting around the electrode plate 5. and the fusing layer 7A can be fused together to form the fused portions 6a, 7a as previously described.
In the specification of the present application, the electrode plate 5 sandwiched between the resin films 6 and 7 and fused together can be referred to as an electrode plate unit.

As shown in FIG. 7, the tip portion 45B of the positive electrode tab 45 is inserted into the through hole 2a of the cover plate 2B from the lower surface side, and the electrode plate 5 having the resin films 6 and 7 on the tip side of the positive electrode tab 45 is subjected to ultrasonic waves. It is joined by a joining method such as welding. Since the lower surface of the electrode plate 5 is exposed in the through hole 7a of the first resin film 7, the tip portion 45B of the positive electrode tab 45 can be easily joined.
Next, as shown in FIG. 7, the tip of the negative electrode tab 35 is attached to the bottom surface or the inner peripheral surface of the lower container 2A by a joining method such as welding, and both the negative electrode tab 35 and the positive electrode tab 45 are folded in a Z shape. The electrode body 3 can be accommodated in the lower container 2A by using the lower container 2A. Also, by bringing the cover plate 2B close to the opening of the lower container 2A, the outer peripheral edge of the cover plate 2B can be joined to the opening of the lower container 2A by a joining method such as welding.

The electrochemical cell 1 having the configuration shown in FIG. 1C can be manufactured by the joining method described above.
The bonding method described above is merely an example, and the manufacturing of the electrochemical cell 1 is not limited to the bonding method shown in FIG.

<Another structural example of the electrode body>
FIG. 9 shows another example of an electrode body composed of a positive electrode body and a negative electrode body. In this example, an electrode body 80 is a band-shaped body formed by connecting a plurality of disk-shaped negative electrode bodies 81 via a connection portion 82 . and belt-like negative electrode bodies each having a plurality of disc-shaped positive electrode bodies 83 connected via connecting portions 84 are alternately laminated in a zigzag shape. A negative electrode tab 86 extends from the outermost negative electrode main body 81 , and a positive electrode tab 87 extends from the outermost positive electrode main body 83 .

In the electrode body 80 having the zigzag structure, depending on the folded state, the negative electrode tab 86 and the positive electrode tab 87 can be extended as shown in FIG.
Even in the case of the electrode body 80 having such a structure, the negative electrode tab 86 and the positive electrode tab 87 are bent and arranged in a Z shape in a side view in the same manner as in the embodiment using the electrode body 3 described above. It can be housed inside to form an electrochemical cell (battery).

There are various configurations for the electrode body applicable to the present invention, such as a structure in which a positive electrode body and a negative electrode body are rolled and housed inside an exterior body 2 shown in FIGS. Various structures may be employed.

<Another structural example of the exterior body>
Various structures of the exterior body have been described based on FIGS. 1 to 4, but in the present invention, as shown in FIG. A battery (electrochemical cell) 25 having a structure consisting of a flat cover plate 2H fixed to the upper part of the side wall by a joining method such as welding so as to close the opening of the lower container 2G may be employed.
In the structure shown in FIG. 10, a through hole 2g is formed in the central portion of the bottom wall 2a, and an electrode plate 5 sandwiched between resin films 6 and 7 is fused to the upper surface of the bottom wall 2a.

The configurations of the electrode plate 5 and the resin films 6 and 7 are the same as those of the electrode plate 5 and the resin films 6 and 7 employed in the embodiment described above with reference to FIGS.
Even if the battery 25 having the configuration shown in FIG. 10 is employed, the same effect as that obtained in the previous embodiment can be obtained.

Further, in the present invention, as shown in FIG. 11, a lower container 2J having a top opening type having a bottom wall 2a and a side wall (peripheral wall) 2b, and an upper part of the side wall by a joining method such as welding so as to close the opening of the lower container 2J. A battery (electrochemical cell) 26 having a structure consisting of a flat plate-like cover plate 2H fixed to the substrate may be employed.
In the structure shown in FIG. 11, a concave portion 2m is formed in the central portion of the bottom wall 2a, a through hole 2n is formed in the central portion of the concave portion 2m, and the resin films 6 and 7 sandwich the resin films 6 and 7 on the upper surface side of the bottom wall 2a. electrode plate 5 is fused.

The configurations of the electrode plate 5 and the resin films 6 and 7 are the same as the configurations of the electrode plate 5 and the resin films 6 and 7 employed in the embodiment described above with reference to FIGS.
Even if the battery 26 having the configuration shown in FIG. 11 is employed, the same effect as that obtained in the previous embodiment can be obtained.

<Other Embodiments of Exterior Body>
In the embodiments up to this point, an embodiment in which a metal battery can (metal can) is applied as the exterior body has been described. Also good.
In this embodiment, as shown in FIG. 12, the outer package is configured by combining a thin cylindrical container-like first container 101 and a second container 102 . The outer peripheral wall 104 of the second container 102 is bent along the entire periphery to have a U-shaped cross section, and the cylindrical outer wall 103 of the first container 101 surrounds the outer peripheral side of the U-shaped bent portion. is provided. Then, the overlapping portions of the outer peripheral wall 103 and the outer peripheral wall 104 are fused.

A disk-shaped negative electrode plate 105 is arranged inside the through hole in the center of the bottom plate of the first container 101, and a disk-shaped protective plate 106 is provided inside the through hole in the center of the top plate of the second container 102. A positive electrode plate 109 is arranged. 12 and 13, the negative electrode sealant ring 107 is arranged adjacent to the negative electrode plate 105, the positive electrode sealant ring 108 is arranged adjacent to the positive electrode plate 109, and the electrodes are arranged between them. A body 110 was placed.

In the present embodiment, the electrode body 3 having the configuration described above can be applied to the electrode body 110 . Alternatively, an electrode body 80 shown in FIG. 9 can be applied.
The first container 101 and the second container 102 are each made of a laminate film (laminate structure). A laminate film consists of a metal foil (metal layer), a bonding layer (resin layer) provided on the overlapping surface (inner surface) that covers the metal foil, and a protective layer (resin layer) that is provided on the outer surface and covers the metal foil. layer). The metal layer is made of, for example, aluminum, stainless steel, or the like, and is formed of a metal foil that blocks outside air and water vapor.

In the configuration shown in FIGS. 12 and 13, through holes 120 are formed in the center portions of the first container 101 and the second container 102, respectively, and the negative electrode plate 105 or the positive electrode plate 109 is provided inside them. However, instead of these structures, a structure in which the electrode plate 5 is covered with the resin films 6 and 7 shown in FIG. 1A and fused together can be applied.
That is, the lid plate 2B portion is regarded as the bottom plate of the first container 101, and a structure is applied in which the electrode plate 5 is covered with the resin films 6 and 7 shown in FIG. be able to.
Also, the lid plate 2B portion is regarded as the top plate of the second container 102, and the electrode plate 5 is covered with the resin films 6 and 7 shown in FIG. can be applied.

"Fabrication of electrode plate unit"
In the above-described embodiments, as shown in FIGS. 1A, 2A, 3A, 4A, etc., after the resin films 6 and 7 are placed in advance on one of the cover plates 2B, 2D, and 2E and the electrode plate 5, , and the process of fusing these are described, but the fusing process is not limited to the process described above.
For example, in the process described above with reference to FIG. 7, the second resin films 6 and 7 are accurately positioned and fused to the electrode plate 5 to form an electrode plate unit in advance. A process of aligning and fusing with the cover plate 2B and then welding the electrode plate 5 to the positive electrode tab 45 was adopted.
According to this process, the electrode plate units are fused to the cover plates 2B, 2D and 2E after the resin films 6 and 7 are accurately positioned with respect to the electrode plate 5, so that the cover plates 2B, 2D and 2E The electrode plate 5 can be precisely fused and fixed to the center of the.

Alternatively, after one of the resin films is fused to the inside or outside of the through hole 2a of the exterior body 2, the electrode plate with the resin film fused is inserted along the one of the resin films to perform alignment. It is also possible to adopt an assembling process of fusing the two later.
Alternatively, the positive electrode tab 45 is previously welded and joined to the electrode plate 5, and the front and back surfaces of the electrode plate 5 to which the positive electrode tab 45 is joined are fused so as to be sandwiched between the resin films 6 and 7, and then fused. The electrode plate 5 having the resin films 6 and 7 may be fused to the cover plate 2B, then the electrode assembly 3 may be accommodated in the lower container 2A, and then the cover plate 2B may be welded to the lower container 2A.

<Fifth Embodiment>
FIG. 14 is a cross-sectional view for explaining a fifth embodiment of an electrochemical cell according to the present invention. The electrochemical cell 50 of the fifth embodiment is a circular button-shaped battery in plan view. In this battery 50, the structure including an outer body 2 made of a metal container and an electrode body 3 housed inside the outer body 2 is the same as that of the third embodiment.

In the electrochemical cell 50 of the fifth embodiment, the electrode plate 5 is fused to the upper surface side of the recess 2e formed in the cover plate 2D by the first resin film 7, which is the same as in the third embodiment. Equivalent to electrochemical cell 15 . The difference is that an insulating film (second resin film) 51 is provided on the upper surface side of the electrode plate 5 . The insulating film 51 has a ring-shaped planar shape, and the electrode plate 5 is exposed to the outside through a through hole 51a formed in the center. The insulating film 51 has an adhesive layer (not shown) on the bottom side. The insulating film 51 is adhered to the upper surface of the cover plate 2D, the upper surface of the peripheral portion of the resin film 7, and the upper surface of the electrode plate 5 via an adhesive layer.
In this embodiment, the peripheral edge side of the first resin film 7 is arranged so as to bulge upward on the peripheral edge side of the electrode plate 5 when the electrode plate 5 is fused. Therefore, the insulating film 51 can adhere to the peripheral side of the first resin film 7, and has the effect of filling the step with the cover plate 2D.
By providing the insulating film 51, the reliability of the sealing structure can be improved as compared with the structure without the insulating film 51 provided. Note that the insulating film 51 may be omitted if the sealing performance by fusion bonding of the first resin film 7 is sufficient.

<Sixth embodiment>
FIG. 15 is a cross-sectional view for explaining a sixth embodiment of an electrochemical cell according to the present invention. An electrochemical cell 55 of the sixth embodiment is a circular button-shaped battery in plan view. In this battery 55, the structure including the outer body 2 made of a metal container and the electrode body 3 housed inside the outer body 2 is the same as that of the second embodiment.

In the electrochemical cell 55 of the sixth embodiment, the electrode plate 5 is fused to the lower surface of the cover plate B with the first resin film 7, which is the same as the electrochemical cell 10 of the second embodiment. is. The difference is that an insulating film (second resin film) 56 is provided on the lower surface side of the electrode plate 5 . The insulating film 56 has a ring-shaped planar shape, and the electrode plate 5 is exposed to the inside of the battery through a through hole 56a formed in the center. The insulating film 56 has an adhesive layer (not shown) on its upper surface. The insulating film 56 is adhered to the lower surface of the peripheral edge portion of the first resin film 7 and the peripheral edge side of the lower surface of the electrode plate 5 via an adhesive layer.
By providing the insulating film 56, the reliability of the sealing structure can be improved as compared with the structure without the insulating film 56 provided. The insulating film 56 may be omitted as long as the sealing property by fusion bonding of the resin film 7 is sufficient. In addition, the insulating film 56 has the effect of preventing short-circuiting of the internal electrodes.

<Seventh Embodiment>
FIG. 16 is a cross-sectional view for explaining a seventh embodiment of an electrochemical cell according to the invention. The electrochemical cell 60 of the seventh embodiment includes a lower container 2G having a bottom wall 2a and a side wall (peripheral wall) 2b with an open upper surface, and a joining method such as welding to close the opening of the lower container. A battery (electrochemical cell) having a structure consisting of a fixed flat cover plate 2H may be employed.
In the structure shown in FIG. 16, a through hole 2g is formed in the central portion of the bottom wall 2a, and the electrode plate 5 is fused to the lower surface side of the bottom wall 2a with the first resin film 7. As shown in FIG. A ring-shaped insulating film (second resin film) 61 is attached to the outer surface of the electrode plate 5 . The outer diameter of the insulating film 61 is formed to be larger than that of the electrode plate 5 , and the electrode plate 5 is sufficiently fixed to the exterior body 2 by closely contacting the outer surface side of the first resin film 7 and the outer surface side of the electrode plate 5 . ing.
Even in the structural example shown in FIG. 16, by providing the insulating film 61, the reliability of the sealing structure can be improved as compared with the structure without the insulating film 61 provided. Note that the insulating film 61 may be omitted if the sealing property by fusion bonding of the first resin film 7 is sufficient. In addition, the insulating film 61 has the effect of preventing short-circuiting of the internal electrodes. As for other functions and effects, the same functions and effects as those of the previous embodiment can be obtained.

<Eighth embodiment>
FIG. 17 is a cross-sectional view for explaining the eighth embodiment of the electrochemical cell according to the invention. The electrochemical cell 65 of the eighth embodiment includes a lower container 2G having an open top and having a bottom wall 2a and a side wall (peripheral wall) 2b, and an upper part of the side wall by a joining method such as welding so as to close the opening of the lower container. A battery (electrochemical cell) having a structure consisting of a fixed flat cover plate 2H may be employed.
In the structure shown in FIG. 17, a through hole 2g is formed in the central portion of the bottom wall 2a, and an electrode plate 5 sandwiched between resin films 6 and 7 is fused to the lower surface of the bottom wall 2a.
An electrochemical cell 65 having the structure shown in FIG. 17 can also obtain the same effect as the previous embodiment.

<Ninth Embodiment>
FIG. 18 is a cross-sectional view for explaining a ninth embodiment of an electrochemical cell according to the present invention. The electrochemical cell 70 of the ninth embodiment includes a bottom opening type lower container 2K having a bottom wall 2a and a side wall (peripheral wall) 2b, and a joining method such as welding to close the opening of the lower container. A battery (electrochemical cell) having a structure consisting of a fixed flat cover plate 2H may be employed.
In the structure shown in FIG. 18, an upward protrusion 2S is formed in the center of the bottom wall 2a, a through hole 2p is formed in the center of the protrusion 2s, and a first resin film 7 is formed on the bottom surface of the bottom wall 2a. The electrode plate 5 is fused by. A ring-shaped insulating film 61 is attached to the outer surface of the electrode plate 5 . The outer diameter of the insulating film 61 is formed to be larger than that of the electrode plate 5 , and the electrode plate 5 is fixed to the exterior body 2 by closely contacting the outer surface side of the first resin film 7 and the outer surface side of the electrode plate 5 . there is
Even in the structural example shown in FIG. 18, by providing the insulating film 61, the reliability of the sealing structure can be improved as compared with the structure without the insulating film 61 provided. Note that the insulating film 61 may be omitted if the sealing property by fusion bonding of the first resin film 7 is sufficient. In addition, the insulating film 61 has the effect of preventing short-circuiting of the internal electrodes. As for other functions and effects, the same functions and effects as those of the previous embodiment can be obtained.
The electrochemical cell 70 having the structure shown in FIG. 18 can also obtain the same effect as the previous embodiment.

<Tenth Embodiment>
FIG. 19 is a cross-sectional view for explaining a tenth embodiment of an electrochemical cell according to the present invention. The electrochemical cell 75 of the tenth embodiment includes a lower container 2K having an open top and having a bottom wall 2a and side walls (peripheral walls) 2b. A battery (electrochemical cell) having a structure consisting of a fixed flat cover plate 2H may be employed.
In the structure shown in FIG. 19, an upward protrusion 2S is formed in the center of the bottom wall 2a, a through hole 2p is formed in the center of the protrusion 2s, and resin films 6 and 7 are formed on the lower surface side of the bottom wall 2a. The sandwiched electrode plates 5 are fused together.
An electrochemical cell 75 having the structure shown in FIG. 19 can also obtain the same effect as the previous embodiment.

1, 10, 15, 20, 50, 55, 60, 65, 70, 75... battery (electrochemical cell), 2... exterior body, 2A, 2G, 2J, 2K... lower container, 2B, 2D, 2E, 2H Lid plate 2d Through hole 3 Electrode body 5 Electrode plate 6 Second resin film (resin cover) 6A Adhesive layer 7 First resin film (sealant film) 7A , 7C... Fusion layer 6B, 7B... Base layer 6b, 7b... Fusion part 51... Insulation film (second resin film) 56... Insulation film (second resin film) 61... Insulation film ( second resin film),
DESCRIPTION OF SYMBOLS 100... Battery (electrochemical cell), 101... 1st container (packing body), 102... 2nd container (packing body), 110... Electrode body.

Claims (8)

1. An exterior having at least one flat surface, a through hole formed inside the peripheral edge of the flat surface, and an electrode plate closing the through hole via a first resin film fused to the peripheral edge of the through hole. equipped with a body,
   The first resin film has an extension portion extending outward from the periphery of the electrode plate, and the first resin film is fused to the electrode plate to form the extension portion and the periphery of the electrode plate. An electrochemical cell, characterized in that a second resin film is fixed to the part.
2. 2. The electrochemical cell according to claim 1, wherein said first resin film and said second resin film are fused together outside the peripheral edge of said electrode plate.
3. A concave portion is formed in the plane, and the through hole formed in the bottom surface of the concave portion is closed by the electrode plate arranged on either side of the bottom surface. 3. An electrochemical cell according to claim 1 or claim 2.
4. At least one of a positive electrode and a negative electrode provided in an electrode body that is housed in the exterior body and electrically connected to the electrode plate is connected to the electrode plate. An electrochemical cell according to any one of the preceding claims.
5. The electrochemical cell according to any one of claims 1 to 4, wherein the exterior body is made of a metal can or a laminate film.
6. 2. The resin film has a laminated structure comprising a fusion layer on the side of the electrode plate and a base layer on the opposite side, and the fusion layer is made of a resin having a lower melting point than that of the base layer. The electrochemical cell according to any one of claims -5.
7. The electrochemical cell according to any one of claims 1 to 6, wherein the first resin film and the second resin film are made of the same material.
8. Claims 1 to 7, wherein the exterior body includes a case having a bottom portion and side portions, and a cover plate for sealing an opening of the case, and the flat surface is provided on the bottom portion. The electrochemical cell according to any one of Claims 1 to 3.

Images