JP6963772B2 - Electrochemical element - Google Patents

Description

The present invention relates to an electrochemical device in which an electrode body is covered with a laminate film outer body.

There is known an electrochemical element in which an electrode body including a positive electrode and a negative electrode is covered with a laminated film outer body and the outer peripheral side of the laminated film outer body is welded.

As an electrochemical element in which the electrode body is covered with the laminate film outer body as described above, for example, a thin battery disclosed in Patent Document 1 is known. Patent Document 1 discloses that, in a state where a thin plate-shaped electrode element is covered with an exterior film, heat welding is performed by pressing the facing edge portion of the exterior film with a heating type pressurizing tool.

Further, Patent Document 1 also discloses that the exterior film is sandwiched between a pair of heating type pressurizing tools having a pressing end face, and the exterior film is heat-welded by applying pressure while heating the exterior film. Has been done. The pressing end face is provided on a pair of heating type pressurizers so as to extend in one direction.

Japanese Unexamined Patent Publication No. 2001-110374

By the way, in the laminated film outer body, a plurality of places on the outer peripheral side of the laminated film outer body are formed by a heating type pressurizing tool (welding and welding tool) as disclosed in Patent Document 1 in a state of covering the electrode body. It is heat welded. At this time, a part of the resin constituting the laminate film exterior body is melted by the heat of the welding tool, and then cooled and cured.

As disclosed in Patent Document 1, a welding tool having a pressing end face extending in one direction is used to heat the outer peripheral side of the laminated film outer body so that the electrode body is sealed by the laminated film outer body. In the case of welding, overlap occurs in the welded portion formed by the pressed end face. As a result, on the outer peripheral side of the laminated film outer body, there is a portion that is once welded by the welding tool and then heated again by the welding tool.

When the portion of the outer peripheral side of the laminated film outer body near the outer peripheral edge is welded using the welding tool, if the above-mentioned overlap of the welded portion is present, the resin melted in the reheated portion. However, it may be extruded by the pressurization of the welding tool and exposed to the outside of the laminated film exterior body.

Then, since the molten resin adheres to the welding tool, the molten resin causes the laminating film outer body to adhere to the welding tool, or the molten resin adheres to the outer surface of the laminating film outer body. It may adhere.

An object of the present invention is that in an electrochemical element in which an electrode body is covered with a laminated film outer body, a resin melted by heat adheres to a welding tool when the outer peripheral side of the laminated film outer body is heat welded. Is to obtain a configuration that can prevent.

The laminated battery according to the embodiment of the present invention includes an electrode body including a positive electrode and a negative electrode, and a sheet-shaped laminated film outer body having a welded portion on the outer peripheral side while covering the electrode body. The welded portion extends in the first direction in a plan view and extends in a second direction intersecting the first direction in a plan view with a first welded portion that welds a part of the outer peripheral side of the laminated film exterior body. It has a second welded portion for welding a part of the outer peripheral side of the laminated film exterior body. The second welded portion is provided so that the tip portion in the second direction overlaps a part of the first welded portion without crossing the first welded portion in the second direction in a plan view. (First configuration).

With the above configuration, in the welded portion located on the outer peripheral side of the laminated film outer body, the portion where the first welded portion extending in the first direction in the plan view and the second welded portion extending in the second direction in the plan view overlap. In a plan view, the second welded portion does not intersect the first welded portion in the second direction. As a result, when the welded portion is formed on the outer peripheral side of the laminated film outer body, the resin melted by heat is exposed to the outside of the laminated film outer body at the portion where the first welded portion and the second welded portion overlap. Can be prevented.

Therefore, when the outer peripheral side of the laminated film outer body is heat-welded, it is possible to prevent the resin melted by heat from adhering to the welding tool.

In addition, when the second welded portion crosses the first welded portion in the second direction, the second welded portion overlaps the first welded portion in the second direction in a plan view, and the second welded portion overlaps the first welded portion in the second direction. 2 It means a state in which the end portion in the second direction of the welded portion overlaps with the end portion in the second direction in the first welded portion or a state in which the end portion protrudes in the second direction from the end portion.

In the first configuration, the first welding portion has a welding main body portion extending in the first direction and a welding protruding portion protruding from the welding main body portion in the second direction. The second welded portion is provided so that the tip portion in the second direction overlaps the welded protruding portion in a plan view (second configuration).

As a result, it is possible to more reliably prevent the second welded portion from crossing the first welded portion in the second direction. Therefore, when the outer peripheral side of the laminated film outer body is heat-welded, it is possible to more reliably prevent the resin melted by heat from adhering to the welding tool.

In the first or second configuration, the electrochemical element further includes a positive electrode connection terminal and a negative electrode connection terminal having one end connected to the electrode body and the other end side extending outward from the laminated film exterior body. The first welded portion is provided so as to include a portion of the laminated film outer body that sandwiches at least one of the positive electrode connection terminal and the negative electrode connection terminal (third configuration).

In the portion of the electrochemical element where at least one of the positive electrode connection terminal and the negative electrode connection terminal is provided, it is preferable to make the welded portion on the outer peripheral side of the laminated film outer body as small as possible in order to secure the internal capacity. In such a case, if there is an overlap of the welded portions as described above on the side where at least one of the positive electrode connection terminal and the negative electrode connection terminal is located in the laminated film outer body, the welded portion is formed on the laminated film outer body. At the time of formation, the resin melted by heat is easily exposed to the outside of the laminated film outer body.

On the other hand, as in the above-described configuration, the welded portion on the side where at least one of the positive electrode connection terminal and the negative electrode connection terminal is located in the laminated film outer body is set as the first welded portion, so that the second welded portion can be viewed in a plan view. Since it is possible to prevent the welded portion from crossing the first welded portion in the second direction, it is possible to prevent the resin melted by heat from being exposed to the outside of the laminated film outer body.

Therefore, in the electrochemical device provided with the positive electrode connection terminal and the negative electrode connection terminal as described above, the above-mentioned first configuration is more effective.

The method for manufacturing an electrochemical element according to an embodiment of the present invention includes an electrode body including a positive electrode and a negative electrode, and a sheet-shaped laminated film outer body in which the outer peripheral side is welded while covering the electrode body. This is a method for manufacturing an electrochemical element. In this method of manufacturing an electrochemical element, the electrode body is covered with the laminated film outer body, and a part of the outer peripheral side of the laminated film outer body is welded to extend in the first direction in a plan view. By welding the first welding portion forming step of forming one welding portion and a part of the outer peripheral side of the laminated film outer body, a second welding portion extending in a second direction intersecting the first direction in a plan view is formed. It has a second welding portion forming step of forming. In the second welding portion forming step, in a plan view, the end portion of the second welding portion overlaps with a part of the first welding portion without crossing the first welding portion in the second direction. The second welded portion is formed in the first method (first method).

As a result, an electrochemical device having the above-mentioned first configuration can be obtained. That is, in the laminated film outer body, it is possible to prevent the second welded portion from crossing the first welded portion in the second direction. Therefore, when the outer peripheral side of the laminated film outer body is heat-welded, it is possible to prevent the resin melted by heat from being exposed to the outside of the laminated film outer body.

In the first method, the first welding portion has a welding main body portion extending in the first direction and a welding protruding portion protruding from the welding main body portion in the second direction in a plan view. In the second welding portion forming step, the second welding portion is formed so that the end portion of the second welding portion overlaps with the welding protruding portion in a plan view (second method).

As a result, it is possible to more reliably prevent the second welded portion from crossing the first welded portion in the second direction. Therefore, when the outer peripheral side of the laminated film outer body is heat-welded, it is possible to more reliably prevent the resin melted by heat from adhering to the welding tool.

In the second method, in the first welding portion forming step, a welding tool having a main body forming portion extending in the first direction and a protruding forming portion protruding from the main body forming portion in the second direction is used. Then, a part of the outer peripheral side of the laminated film outer body is welded to form the first welded portion (third method).

As a result, it is possible to form a first welded portion having a welded main body portion extending in the first direction and a welded protruding portion protruding in the second direction from the welded main body portion as the welded portion of the outer body of the laminated film. That is, the above-mentioned second method can be realized.

The apparatus for manufacturing an electrochemical element according to an embodiment of the present invention comprises an electrode body including a positive electrode and a negative electrode, and a sheet-shaped laminated film outer body having a welded portion on the outer peripheral side while covering the electrode body. It is a manufacturing apparatus for manufacturing an electrochemical element provided. This manufacturing apparatus has a main body forming portion extending in the first direction and a protruding forming portion protruding from the tool main body portion in a second direction intersecting the first direction in a plan view, and the laminated film exterior body is formed. A pair of first welding tools that form a first welding portion as a part of the welding portion on the laminated film outer body by sandwiching and heating, and the first welding portion with respect to the first welding portion in a plan view. The laminated film is heated by sandwiching the outer body of the laminated film in a state where the end portion in the second direction is positioned so as to overlap a part of the first welding portion without crossing the second direction. The exterior body is provided with a pair of second welding tools for forming a second welding portion as a part of the welding portion (first configuration).

As a result, as a welding portion of the outer body of the laminated film, it is possible to form a first welding portion having a welding main body portion extending in the first direction and a welding protruding portion protruding in the second direction from the welding main body portion. In a plan view, it is possible to form a second welded portion that overlaps the welded protrusion without crossing the first welded portion in the second direction. Therefore, in the portion where the first welded portion and the second welded portion overlap, when the outer peripheral side of the laminated film outer body is heat-welded, the resin melted by heat is exposed to the outside of the laminated film outer body. Can be prevented.

Therefore, it is possible to prevent the molten resin from adhering to the welding tool when the outer peripheral side of the laminated film outer body is heat-welded.

According to the electrochemical element according to the embodiment of the present invention, the welded portion of the laminated film outer body to which the outer peripheral side is welded while covering the electrode body is the first welded portion extending in the first direction in a plan view. It has a second welded portion extending in a second direction intersecting the first direction. The second welded portion is provided so that the end portion of the second welded portion overlaps a part of the first welded portion without crossing the first welded portion in the second direction in a plan view. Has been done. This makes it possible to prevent the molten resin from adhering to the welding tool when the outer peripheral side of the laminated film outer body is heat-welded.

FIG. 1 is a perspective view showing a schematic configuration of a laminated battery according to an embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. FIG. 3 is a diagram schematically showing a state in which a first seal portion is formed on a laminated film exterior body by a first welding tool of a welding device. FIG. 4 is a diagram schematically showing a state in which a second seal portion is formed on the outer body of the laminated film by the second welding tool of the welding device. FIG. 5 is a diagram showing the pressing positions of the first welding tool and the second welding tool of the welding device against the outer body of the laminated film. FIG. 6 is a diagram showing a state in which a seal portion is formed on the outer body of the laminated film by the first welding tool and the second welding tool of the welding device. FIG. 7 is a diagram showing the pressing positions of the first welding tool and the second welding tool of the welding device against the laminate film exterior body in the laminated battery according to the other embodiment. FIG. 8 is a diagram showing a state in which a seal portion is formed on a laminated film outer body by a first welding tool and a second welding tool of a welding device in a laminated battery according to another embodiment. FIG. 9 is a diagram showing a pressing position of the laminated film outer body by a welding tool in the conventional method of forming a seal portion on the outer peripheral side of the laminated film outer body.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

(overall structure)
FIG. 1 is a perspective view showing a schematic configuration of a laminated battery 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a schematic configuration of the laminated battery 1. The laminated battery 1 is a secondary battery having a rectangular shape in a plan view in which an electrode body 10 functioning as a power generator is covered with a laminated film exterior body 20. In FIG. 2, a part of the electrode body 10 is not shown.

As shown in FIGS. 1 and 2, the laminated battery 1 includes an electrode body 10 and a laminated film exterior body 20 that covers the electrode body 10. Further, the laminated battery 1 includes a positive electrode connection terminal 41 and a negative electrode connection terminal 42 that are electrically connected to the positive electrode 11 and the negative electrode 12 of the electrode body 10, respectively. A non-aqueous electrolytic solution is also sealed inside the laminated battery 1.

The laminated film exterior body 20 is made of a material in which one side of an aluminum metal foil is covered with nylon and the other side is covered with polypropylene. That is, the laminated film exterior body 20 is made of a material obtained by laminating aluminum with nylon and polypropylene.

The laminated film outer body 20 is welded by applying pressure while heating in a state where polypropylenes of the laminated film outer body 20 are overlapped with each other. That is, since the polypropylene of the laminated film outer body 20 is melted by heating, the polypropylenes of the laminated film outer body 20 are heated in a state of being overlapped with each other as described above, and then cooled to form the laminated film outer bodies 20 with each other. Can be welded.

The laminated film exterior body 20 is formed in a substantially rectangular shape. By welding the outer peripheral sides of the laminated film exterior 20 with the electrode body 10 sandwiched between the pair of laminated film exteriors 20, the bulging portion 1a and the sealing portion 1b as shown in FIGS. 1 and 2 are welded to each other. (Welding part) is formed. That is, the bulging portion 1a is formed by covering the electrode body 10 with the laminated film outer body 20, and the laminated film outer bodies 20 are welded to each other around the bulging portion 1a to seal the bulging portion 1a. Part 1b is formed. In FIG. 1, for the sake of explanation, the seal portion 1b is shown by an oblique line.

As will be described later, in the present embodiment, the electrode body 10 is formed by crushing a cylindrical wound electrode body into a flat shape. That is, the electrode body 10 has a rectangular shape when viewed from the side. Therefore, as shown in FIG. 1, the bulging portion 1a has a rectangular shape in a plan view (hereinafter, also simply referred to as a plan view) of the laminated film exterior body 20. The seal portion 1b is formed around the bulging portion 1a so that the laminated battery 1 has a rectangular shape in a plan view.

Further, in the pair of laminated film exterior bodies 20, as shown in FIG. 2, the laminated battery 1 has a flat surface portion 1c on one side in the thickness direction of the electrode body 10 and the other side in the thickness direction of the electrode body 10. The outer peripheral sides of the laminated film outer body 20 are welded to each other with the electrode body 10 sandwiched so as to have the above-mentioned bulging portion 1a. That is, of the pair of laminated film exterior bodies 20, one of the laminated film exterior bodies 20 is arranged so as to follow the outer shape of the electrode body 10.

The detailed configuration of the sealing portion 1b of the laminated film exterior body 20 will be described later.

Although not particularly shown, the electrode body 10 is a flat wound electrode body formed in an ellipse when viewed from the winding axis direction. The electrode body 10 is wound after winding the positive electrode 11 and the negative electrode 12 formed in a band shape in a state of being superposed so that the band-shaped separator 13 is located between the two and under the positive electrode 11, and then crushed. By being formed flat, it is formed. The flat electrode body 10 is housed in the space formed by the laminated film exterior body 20.

Although not particularly shown, the positive electrode 11 has a positive electrode current collector made of a metal foil such as aluminum and a positive electrode active material layer containing a positive electrode active material and provided on both sides of the positive electrode current collector. Specifically, the positive electrode 11 is coated with a positive electrode mixture containing a positive electrode active material, a conductive auxiliary agent, a binder, etc., which are lithium-containing oxides capable of storing and releasing lithium ions, on a positive electrode current collector made of aluminum foil or the like. It is formed by drying. As the lithium-containing oxide as the positive electrode active material, for example, _{a lithium cobalt oxide such as LiCoO 2} , a lithium manganese oxide such as LiMn ₂ O ₄ , or a lithium composite oxide such as a lithium nickel oxide such as LiNiO _{2 is used.} Is preferable. As the positive electrode active material, only one kind of substance may be used, or two or more kinds of substances may be used. Further, the positive electrode active material is not limited to the above-mentioned substances.

The negative electrode 12 has a negative electrode current collector made of a metal foil such as copper, and a negative electrode active material layer containing a negative electrode active material and provided on both sides of the negative electrode current collector. Specifically, the negative electrode 12 is dried by applying a negative electrode mixture containing a negative electrode active material capable of occluding and releasing lithium ions, a conductive auxiliary agent, a binder, and the like onto a negative electrode current collector made of copper foil or the like. It is formed. As the negative electrode active material, for example, it is preferable to use a carbon material (graphites, pyrolytic carbons, cokes, glassy carbons, etc.) capable of occluding and releasing lithium ions. The negative electrode active material is not limited to the above-mentioned substances.

A part of the positive electrode current collector is exposed at the positive electrode 11, and the positive electrode connection terminal 41 is connected to the exposed portion. Similarly, a part of the negative electrode current collector is exposed in the negative electrode 12, and the negative electrode connection terminal 42 is connected to the exposed part. The positive electrode connection terminal 41 and the negative electrode connection terminal 42 are drawn out of the electrode body 10 and out of the laminate film outer body 20.

The positive electrode connection terminal 41 is made of an aluminum metal foil formed in a rectangular shape in a plan view. One side of the positive electrode connection terminal 41 in the longitudinal direction is connected to the positive electrode current collector by welding, and the other side in the longitudinal direction is located outside the laminate film exterior body 20 (see FIGS. 1 and 2). That is, the positive electrode connection terminal 41 is sandwiched by the laminated film outer body 20, and extends from the inside to the outside of the laminated film outer body 20.

The negative electrode connection terminal 42 is made of a metal foil such as copper or nickel formed in a rectangular shape in a plan view. One side of the negative electrode connection terminal 42 in the longitudinal direction is connected to the negative electrode current collector by welding, and the other side in the longitudinal direction is located outside the laminate film exterior body 20. That is, the negative electrode connection terminal 42 is sandwiched by the laminate film exterior body 20, and extends from the inside to the outside of the laminate film exterior body 20.

By using the positive electrode connection terminal 41 and the negative electrode connection terminal 42 having the above-described configuration in the laminated battery 1, the impedance can be reduced as compared with the configuration in which the connection terminal is pulled out to the outside via other connection components. can.

(Seal part)
Next, the configuration of the seal portion 1b provided on the outer peripheral side of the laminated film exterior body 20 of the laminated battery 1 will be described with reference to FIGS. 1 and 6. FIG. 6 is a diagram showing a state before cutting the welded laminated film exterior body 20.

The seal portions 1b are formed on a pair of first seal portions 21 and 22 (first welded portions) provided on the end side in the longitudinal direction of the laminated battery 1 and on the end side in the lateral direction of the laminated battery 1. It has a pair of second seal portions 23, 24 (second welded portions) provided. A part of the first seal portions 21 and 22 and a part of the second seal portions 23 and 24 are partially overlapped in a plan view. That is, the seal portion 1b has an overlapping region 25 in which the first seal portions 21 and 22 and the second seal portions 23 and 24 overlap in a plan view.

The pair of first seal portions 21 and 22 are provided at both ends in the longitudinal direction of the laminated battery 1. That is, the first seal portion 21 is provided at one end of the laminated battery 1 in the longitudinal direction, and the first seal portion 22 is provided at the other end of the laminated battery 1 in the longitudinal direction. In the first seal portion 21, the positive electrode connection terminal 41 and the negative electrode connection terminal 42, which will be described later, are fixed by being welded to each other in a state of being sandwiched between the pair of laminated film outer bodies 20. ..

The pair of first seal portions 21 and 22 are provided so as to extend in the lateral direction (first direction) of the laminated battery 1, respectively. The pair of first seal portions 21 and 22 are each formed in a C shape in a plan view. Specifically, the pair of first seal portions 21 and 22 are a pair of welding main bodies 21a and 22a extending in the lateral direction and a pair protruding in the longitudinal direction from both ends of the welding main bodies 21a and 22a in a plan view. Has welded protrusions 21b and 22b. The welded projecting portions 21b and 22b are rectangular in a plan view, and project from both ends of the welding main body portions 21a and 22a in the lateral direction in the same direction (inside of the laminated battery 1) in the longitudinal direction. There is.

The pair of second seal portions 23, 24 are provided at both ends of the laminated battery 1 in the lateral direction. That is, the second seal portion 23 is provided at one end of the laminated battery 1 in the lateral direction, and the second seal portion 24 is provided at the other end of the laminated battery 1 in the lateral direction. There is.

The pair of second seal portions 23, 24 are provided so as to extend in the longitudinal direction (second direction) of the laminated battery 1, respectively. The pair of second seal portions 23 and 24 are formed in a straight line, respectively.

Both ends of the pair of second seal portions 23 and 24 in the longitudinal direction overlap with the welded protrusions 21b and 22b of the pair of first seal portions 21 and 22 in a plan view. That is, one end of the second seal portion 23 in the longitudinal direction overlaps with the welding protrusion 21b of the first seal portion 21, and the other end of the second seal portion 23 in the longitudinal direction is the second. 1 It overlaps with the welded protrusion 22b of the seal portion 22. Further, one end of the second seal portion 24 in the longitudinal direction overlaps with the welding protrusion 21b of the first seal portion 21, and the other end of the second seal portion 24 in the longitudinal direction is the second. 1 It overlaps with the welded protrusion 22b of the seal portion 22.

The overlapping portions of the welding protrusions 21b and 22b of the pair of first seal portions 21 and 22 and the pair of second seal portions 23 and 24 are the overlapping regions 25, respectively. In the present embodiment, the overlapping regions 25 are formed at four locations on the lateral side (long side side of the laminated battery 1) with respect to the bulging portion 1a of the laminated battery 1.

(Welding device)
Next, in the laminated battery 1 having the above-described configuration, a welding device 100 (a device for manufacturing an electrochemical element) for forming a seal portion 1b on the laminated film exterior body 20 is used with reference to FIGS. 3 and 4. I will explain. FIG. 3 is a diagram schematically showing a state in which the first sealing portion 21 is formed on the laminated film exterior body 20 by the first welding and wearing tools 101 and 102 of the welding device 100. FIG. 4 is a diagram schematically showing how the second sealing portion 24 is formed on the laminated film exterior body 20 by the second welding and wearing tools 111 and 112 of the welding device 100. For convenience of explanation, only a part of the welding device 100 is shown in FIGS. 3 and 4, respectively.

The welding device 100 welds the laminated film outer body 20 by heating the laminated film outer body 20 in a state of being sandwiched between the pair of first welding and wearing tools 101 and 102 and the second welding and wearing tools 111 and 112. Specifically, the welding device 100 includes a pair of first welding tools 101 and 102 arranged to face each other in the vertical direction and a pair of second welding tools 111 and 112 arranged to face each other in the vertical direction. And have. At least one of the first welding tools 101 and 102 and the second welding tools 111 and 112 may be arranged so as to face each other in a direction other than the vertical direction.

Although not particularly shown, the welding device 100 has a heating device that heats a pair of first welding tools 101 and 102 and second welding tools 111 and 112. Further, the welding device 100 includes a driving device for driving the pair of first welding tools 101 and 102 so as to be close to each other, and a driving device for driving the second welding tools 111 and 112 so as to be close to each other. The welding device 100 may be one device in which a pair of first welding tools 101 and 102 and a pair of second welding tools 111 and 112 are provided side by side, or a pair of first welding tools. The tools 101 and 102 and the pair of second welding tools 111 and 112 may be units provided in different devices.

The first welding tools 101 and 102 form the first sealing portions 21 and 22 by heating the laminated film outer body 20 in a sandwiched state. Specifically, as shown in FIG. 3, the first welding tools 101 and 102 have pressing surfaces 101a and 102a corresponding to the shapes of the first sealing portions 21 and 22, respectively. The pressing surfaces 101a and 102a have the same shape. The first welding tools 101 and 102 are arranged so that the pressing surfaces 101a and 102a face each other.

On the pair of pressing surfaces 101a and 102a, a main body forming portion 103 for forming the welding main body portions 21a and 22a of the first sealing portions 21 and 22, and a welding protruding portion 21b of the first sealing portions 21 and 22, respectively. A protrusion forming portion 104 for forming 22b is provided. The main body forming portion 103 is formed on the first welding tools 101 and 102 so as to extend in one direction. The protrusion forming portion 104 is formed on the first welding tools 101 and 102 so as to protrude from both sides of the main body forming portion 103 in the one direction in the same direction intersecting the one direction.

In the example shown in FIG. 3, the positive electrode connecting terminal 41 and the negative electrode connecting terminal 42 side of the longitudinal end portions of the laminated film exterior body 20 are positioned between the pair of pressing surfaces 101a and 102a. In this state, the laminated film outer body 20 is sandwiched between the pair of pressing surfaces 101a and 102a and heated to form the first sealing portion 21 on the laminated film outer body 20. The dotted region shown in FIG. 3 is a region (planned formation region) in which the first seal portion 21 is planned to be formed on the laminated film exterior body 20. Although not particularly shown, when the first seal portion 22 is formed on the laminated film exterior body 20, a pair of regions in which the first seal portion 22 is to be formed are positioned between the pair of pressing surfaces 101a and 102a. The laminated film exterior body 20 is sandwiched between the pressing surfaces 101a and 102a and heated.

As described above, when the laminated film exterior body 20 is arranged between the pair of pressing surfaces 101a and 102a, the one direction coincides with the lateral direction of the laminated film exterior body 20, and the one direction coincides with the one direction. The laminated film exterior body 20 is arranged so that the intersecting directions coincide with the longitudinal direction of the laminated film exterior body 20.

The second welding tools 111 and 112 form the second sealing portions 23 and 24 by heating the laminated film outer body 20 in a sandwiched state. Specifically, as shown in FIG. 4, the second welding tools 111 and 112 have pressing surfaces 111a and 112a according to the shapes of the second sealing portions 23 and 24, respectively. The pressing surfaces 111a and 112a have the same shape. The second welding tools 111 and 112 are arranged so that the pressing surfaces 111a and 112a face each other.

The pair of pressing surfaces 111a and 112a are provided with a linear second seal portion forming portion 113 extending in one direction.

In the example shown in FIG. 4, the end portion of the laminated film exterior body 20 in the lateral direction is positioned between the pair of pressing surfaces 111a and 112a. In this state, the laminated film outer body 20 is sandwiched between the pair of pressing surfaces 111a and 112a and heated to form the second sealing portion 24 on the laminated film outer body 20. The dotted region shown in FIG. 4 is a region (planned formation region) in which the second seal portion 24 is planned to be formed on the laminated film exterior body 20. Although not particularly shown, when the second seal portion 23 is formed on the laminated film exterior body 20, a pair of regions to be formed of the first seal portion 22 are positioned between the pair of pressing surfaces 101a and 102a. The laminated film exterior body 20 is sandwiched between the pressing surfaces 101a and 102a and heated.

As described above, when the laminated film outer body 20 is arranged between the pair of pressing surfaces 111a and 112a, the laminated film outer body is arranged so that the one direction coincides with the longitudinal direction of the laminated film outer body 20. Body 20 is arranged.

(Manufacturing method of laminated battery)
Next, a method of manufacturing the laminated battery 1 having the above-described configuration will be described with reference to FIGS. 5 and 6. The welding method for welding the outer peripheral side of the laminated film exterior body 20 is a part of the manufacturing method for the laminated battery 1.

FIG. 5 is a diagram showing the pressing positions of the first welding and welding tools 101 and 102 and the second welding and welding tools 111 and 112 of the welding device 100 against the laminated film exterior body 20. FIG. 6 is a diagram showing a state in which the sealing portion 1b is formed on the laminated film outer body 20 by the first welding and welding tools 101 and 102 and the second welding and welding tools 111 and 112 of the welding apparatus 100.

In FIG. 5, the pressing positions of the first welding tools 101 and 102 against the laminated film outer body 20 are indicated by a dotted line, and the pressing positions of the second welding tools 111 and 112 against the laminated film outer body 20 are indicated by dotted lines. .. Further, in FIG. 6, for the sake of explanation, the seal portion 1b is shown by an oblique line.

First, the electrode body 10 which is a wound electrode body is manufactured by the same method as the conventional method. After that, the outer peripheral side of the laminated film outer body 20 is welded by the welding device 100 in a state where the electrode body 10 is sandwiched between the two laminated film outer bodies 20 cut to a predetermined size.

Since the method for manufacturing the electrode body 10 is the same as the conventional method, detailed description thereof will be omitted.

When the laminating film outer body 20 is welded by the welding device 100, as shown in FIG. 5, the first welding tools 101 and 102 of the welding device 100 are used with respect to the longitudinal end of the laminating film outer body 20. Position the pressing surfaces 101a and 102a (see the alternate long and short dash line in FIG. 5). Note that FIG. 5 shows the first welding of the welding device 100 at one end (the end where the positive electrode connection terminal 41 and the negative electrode connection terminal 42 are positioned) of both ends of the laminated film exterior body 20 in the longitudinal direction. The positions to be sandwiched by the tools 101 and 102 are shown.

A part of the outer peripheral side of the laminated film exterior body 20 is welded by the first welding tools 101 and 102 of the welding device 100. As a result, the first seal portion 21 is formed.

Similarly, of the both ends in the longitudinal direction of the laminated film exterior body 20, the other end is also welded to a part of the outer peripheral side of the laminated film exterior body 20 by the first welding tools 101 and 102 of the welding device 100. do. As a result, the first seal portion 22 is formed.

The step of forming the first seal portions 21 and 22 in this way corresponds to the step of forming the first welded portion.

After that, as shown in FIG. 5, the pressing surfaces 111a, 112a of the second welding tools 111, 112 of the welding device 100 are applied to one end of both ends of the laminated film exterior body 20 in the lateral direction. Position (see dotted line in FIG. 5). At this time, the laminated film exterior body 20 is arranged so that the end portion of the second seal portion forming portion 113 overlaps the welding protrusion 21b of the first seal portion 21 in a plan view with respect to the pressing surfaces 111a and 112a. .. Then, a part of the outer peripheral side of the laminated film exterior body 20 is welded by the second welding tools 111 and 112 of the welding device 100. As a result, the second seal portion 23 is formed.

Similarly, the other end of both ends of the laminated film exterior 20 in the lateral direction is also partially welded on the outer peripheral side of the laminated film exterior 20 by the second welding tools 111 and 112 of the welding device 100. do. As a result, the second seal portion 24 is formed.

Before forming the second sealing portion 24 on the laminated film exterior body 20 by the second welding and wearing tools 111 and 112 of the welding device 100, non-aqueous electrolysis was performed in the space formed by the pair of laminated film exterior bodies 20. Inject the liquid.

The step of forming the second seal portions 23 and 24 corresponds to the step of forming the second welded portion.

FIG. 6 shows a state in which the first sealing portions 21 and 22 and the second sealing portions 23 and 24 are formed on the laminated film exterior body 20. As shown in FIG. 6, the second seal portions 23 and 24 are formed so as to overlap the welded protrusions 21b and 22b of the first seal portions 21 and 22 in a plan view.

Then, by cutting the laminated film outer body 20 on the outside of the second sealing portions 23 and 24 in the lateral direction of the laminated film outer body 20, the laminated battery 1 shown in FIG. 1 can be obtained.

Here, FIG. 9 shows the pressing position of the laminated film outer body by the welding tool in the conventional method of forming the seal portion on the outer peripheral side of the laminated film outer body. In FIG. 9, the pressing position of the welding tool pressing surface 301a against the laminated film outer body is indicated by a chain line, and the pressing position of the welding tool pressing surface 311a against the laminated film outer body is indicated by a dotted line. As shown in FIG. 9, the pressing surfaces 301a and 311a of the welding tool that press the laminated film outer body are both linear. The detailed configuration of the welding tool will not be described.

In the conventional welding method, when the longitudinal end of the laminated film outer body is welded by the pressing surface 301a of the welding tool and then the short end of the laminated film outer body is welded by the pressing surface 311a of the welding tool. In plan view, the pressing surface 311a crosses the seal portion formed by the pressing surface 301a. Then, when the laminated film outer body is pressed by the pressing surface 311a, the resin melted by heat is exposed to the outside of the laminated film outer body (see X in FIG. 9).

When the molten resin is exposed to the outside of the outer body of the laminated film in this way, the molten resin adheres to the pressing surface 311a of the welding tool. As a result, the molten resin causes the laminated film outer body to adhere to the welding tool, or the molten resin adheres to the outer surface of the laminated film outer body.

On the other hand, in the present embodiment, among the sealing portions 1b formed on the outer peripheral side of the laminated film exterior body 20, the first sealing portions 21 and 22 provided at the end portions in the longitudinal direction of the laminated battery 1 are laminated. It has welding main bodies 21a and 22a extending in the lateral direction of the shape battery 1 and welding protrusions 21b and 22b protruding from the welding main bodies 21a and 22a in the same direction in the longitudinal direction of the laminated battery 1. Of the seal portions 1b, the second seal portions 23 and 24 provided at the lateral end of the laminated battery 1 are welded and projected of the first seal portions 21 and 22 at the longitudinal end in a plan view. It is provided so as to overlap the portions 21b and 22b.

As a result, in the portion where the first seal portions 21 and 22 and the second seal portions 23 and 24 overlap, the first seal portions 21 and 22 are formed on the laminated film exterior body 20, and then the second seal portions 23 and 24 are formed. When formed, it is possible to prevent the resin melted by the heat of the second seal portion forming portion 113 from being exposed to the outside from the laminated film exterior body 20.

Therefore, it is possible to prevent the molten resin from adhering to the welding tool that forms the seal portion. This makes it possible to prevent the laminated film outer body from adhering to the welding tool due to the molten resin and the molten resin from adhering to the outer surface of the laminated film outer body.

Further, in the above embodiment, the first seal portion 21 is provided on the side of the laminated film exterior body 20 where the positive electrode connection terminal 41 and the negative electrode connection terminal 42 are located.

In the portion of the laminated battery in which the positive electrode connection terminal and the negative electrode connection terminal are provided, it is preferable to make the welded portion on the outer peripheral side of the laminated film outer body as small as possible in order to secure the internal capacity. In such a case, if there is an overlap of the seal portions on the side where the positive electrode connection terminal and the negative electrode connection terminal are located in the laminated film outer body, the resin melted by heat when the seal portion is formed on the laminated film outer body. Is easily exposed to the outside of the laminated film exterior.

On the other hand, as described above, by forming the first seal portion 21 on the side where at least one of the positive electrode connection terminal 41 and the negative electrode connection terminal 42 is located in the laminated film exterior body 20, in a plan view, It is possible to prevent the second seals 23 and 24 from crossing the first seal portion 21 in the longitudinal direction of the laminated film exterior body 20. As a result, when the seal portion 1b is formed on the laminated film outer body 20, it is possible to prevent the resin melted by heat from being exposed to the outside of the laminated film outer body 20.

(Other embodiments)
Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the embodiment is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented within a range that does not deviate from the gist thereof.

In the above embodiment, the pressing surfaces 101a and 102a of the first welding tools 101 and 102 have a main body forming portion 103 for forming the welding main bodies 21a and 22a of the first sealing portions 21 and 22, respectively, and a first. 1 A protrusion forming portion 104 for forming the welded protrusions 21b and 22b of the seal portions 21 and 22 is provided.

However, as shown in FIG. 7, on the pressing surfaces 201a and 202a of the first welding tool, protrusion forming portions 204 may be provided at both ends of the main body forming portion 203 extending in one direction in the extending direction, respectively. .. The protrusion forming portion 204 forms the main body in a range from the position where the welding protrusions 21b and 22b of the first seal portions 21 and 22 are formed to the closer end of both ends in the stretching direction of the main body forming portion 203. It protrudes from the portion 203 in the same direction as the direction intersecting the one direction. By using the first welding tool having the pressing surfaces 201a and 202a, as shown in FIG. 8, the first sealing portions 121 and 122 having the welding protrusions 121b and 122b can be formed. Reference numerals 121a and 122a in FIG. 8 are welding main body portions 121a and 122a of the first sealing portions 121 and 122 formed by the main body forming portions 203 on the pressing surfaces 201a and 202a of the first welding tool.

In the above embodiment, the outer peripheral sides of the pair of laminated film outer bodies 20 are welded to each other, but the present invention is not limited to this, and one laminated film outer body is folded back and welded so as to sandwich the electrode body 10. May be good. The direction in which the laminated film exterior body is folded back may be the stretching direction of the positive electrode connection terminal 41 and the negative electrode connection terminal 42 with respect to the electrode body 10, or may be the width direction. That is, in the above-described embodiment, both ends in the longitudinal direction and both ends in the lateral direction of the laminated film exterior body 20 are welded. However, the laminated film exterior body may be formed by folding back any one of the end portion in the longitudinal direction and the end portion in the lateral direction. Therefore, in the laminated film exterior body, the first seal portion may be formed on only one of the ends in the longitudinal direction, or the second seal portion may be formed on only one of the ends in the lateral direction. May be good.

In the above embodiment, the first seal portions 21 and 22 are formed on the laminated film exterior body 20, and then the second seal portions 23 and 24 are formed. However, the first seal portion may be formed after the second seal portion is formed on the outer body of the laminated film. Further, after forming the first seal portion at one end in the longitudinal direction of the laminated film outer body, the second seal portion is formed, and then the first seal is formed at the other end in the longitudinal direction of the laminated film outer body. Part may be formed. Further, after forming the second seal portion at one end in the lateral direction of the laminated film exterior body, the first seal portion is formed, and then the second seal portion is formed at the other end portion in the lateral direction of the laminated film exterior body. Two seals may be formed. Further, the first seal portion and the second seal portion may be alternately formed on the laminated film outer body. That is, the order of the first seal portion and the second seal portion formed on the laminate film outer body may be any order.

From the viewpoint of the productivity of the laminated battery 1, it is preferable that the ends of the laminated film exterior 20 where the positive electrode connection terminal 41 and the negative electrode connection terminal 42 are located are first welded.

In the above embodiment, the first sealing portions 21 and 22 are formed on the laminated film exterior body 20, and then the second sealing portions 23 and 24 are formed. However, the first seal portion and the second seal portion may be formed on the laminate film outer body at the same time. In this case, since it is necessary to inject the non-aqueous electrolytic solution into the space formed by the laminated film outer body, it is necessary to weld a part of the outer peripheral side of the laminated film outer body after injecting the non-aqueous electrolytic solution. .. Therefore, in the portion where the first seal portion and the second seal portion formed at the same time and the seal portion formed later overlap each other, when the seal portion is formed later, the resin melted by heat is laminated film. When there is a possibility of being exposed to the outside of the exterior body, it is preferable to apply the configuration of the embodiment to the overlapping portion.

In the above embodiment, the first sealing portions 21 and 22 are formed at both ends in the longitudinal direction of the laminated film exterior body 20, and the second sealing portions 23 and 24 are both ends in the lateral direction of the laminated film exterior body 20. Is formed in. However, the first sealing portion may be formed at both ends in the lateral direction of the laminated film exterior body, and the second sealing portion may be formed at both ends in the longitudinal direction of the laminated film exterior body.

From the viewpoint of the battery capacity of the laminated battery, the first seal portion is preferably formed on the side where at least one of the positive electrode connection terminal and the negative electrode connection terminal is located in the laminated film exterior body.

In the above embodiment, the first seal portions 21 and 22 have the same shape in a plan view. Further, the second seal portions 23 and 24 have the same shape in a plan view. However, the first seal portions 21 and 22 may have different shapes in a plan view. Further, the second seal portions 23 and 24 may have different shapes in a plan view.

In the above embodiment, the first seal portions 21 and 22 extend in the lateral direction (first direction) of the laminated battery 1, and the second seal portions 23 and 24 extend in the longitudinal direction (second direction) of the laminated battery 1. ). That is, the stretching direction of the second sealing portions 23 and 24 is a direction orthogonal to the stretching direction of the first sealing portions 21 and 22 in a plan view. However, the stretching direction of the second sealing portion does not have to be orthogonal as long as it intersects the stretching direction of the first sealing portion in a plan view.

In the above-described embodiment, the first seal portions 21 and 22 have a welding main body portions 21a and 22a extending in the lateral direction of the laminated battery 1 and a welding protrusion extending from the welding main bodies 21a and 22a in the longitudinal direction of the laminated battery 1. It has parts 21b and 22b. However, the first seal portion may be formed in a straight line extending in the lateral direction of the laminated battery 1. That is, the first seal portion does not have to have the welded protrusion as in the above embodiment. In this case, in a plan view, the second seal portion does not cross the first seal portion in the longitudinal direction of the laminated battery 1, and the end portion in the longitudinal direction is a part of the first seal portion. It is formed on the laminated battery 1 so as to overlap each other.

In the above embodiment, the welded protrusions 21b and 22b of the first seal portions 21 and 22 have a rectangular shape in a plan view. However, the welded protrusion of the first seal portion may have another shape as long as it can be formed by overlapping the second seal portions, such as a circular shape or a triangular shape in a plan view.

In the above embodiment, the welding main body portions 21a and 22a of the first seal portions 21 and 22 are linear, and the second seal portions 23 and 24 are also linear. However, at least one of the welding main body portion and the second seal portion of the first seal portion may have a shape other than the linear shape.

In the above embodiment, the electrode body 10 is a wound electrode body obtained by winding a strip-shaped positive electrode 11, a negative electrode 12, and a separator 13 in a state of being overlapped in the thickness direction, respectively. However, the electrode body may be a laminated electrode body obtained by stacking a sheet-shaped positive electrode, a negative electrode, and a separator in the thickness direction, respectively.

In the above embodiment, the laminated film exterior body 20 is made of a material obtained by laminating a metal foil made of aluminum with nylon and polypropylene. However, the metal foil of the laminate film exterior is not limited to aluminum, and may be formed of other metal materials such as stainless steel. Further, as the material used for the welded portion of the outer body of the laminated film, any material may be used as long as it is a material that melts by heat, cures by cooling, and does not melt by a non-aqueous electrolytic solution. Further, in the laminated film exterior body, any material other than the welded portion may be used as long as it is a material capable of laminating a metal foil.

In the above embodiment, the laminated battery is formed in a rectangular shape in a plan view. However, the laminated battery may have other shapes such as a polygonal shape. Also in this case, the first direction, which is the stretching direction of the first seal portion, and the second direction, which is the stretching direction of the second seal portion, intersect in a plan view.

In the above embodiment, the laminated battery 1 is a lithium ion battery. However, the laminated battery 1 may be a battery other than the lithium ion battery. Further, the configuration of the above embodiment may be applied not only to a laminated battery but also to an electrochemical element including a capacitor and the like. That is, the configuration of the above embodiment can be applied to an electrochemical device capable of storing electricity or generating electricity and having a welded portion formed on the outer peripheral side of the laminated film outer body covering the electrode body.

The present invention can be used for a laminated battery in which an electrode body is covered with a laminated film outer body.

1 Laminated battery (electrochemical element)
1a bulging part 1b Sealed part (welded part)
10 Electrode body 11 Positive electrode 12 Negative electrode 20 Laminated film exterior body 21, 22, 121, 122 First seal portion (first welded portion)
21a, 22a, 121a, 122a Welding main body 21b, 22b, 121b, 122b Welding protrusions 23, 24 Second sealing part (second welding part)
25 Overlapping region 41 Positive electrode connection terminal 42 Negative electrode connection terminal 100 Welding device (electrochemical element manufacturing device)
101, 102 First plastic welding tool 101a, 102a, 201a, 202a Pressing surface 103, 203 Main body forming portion 104, 204 Protruding forming portion 111, 112 Second welding tool 111a, 112a Pressing surface 113 Second sealing portion forming portion

Claims (5)

An electrode body including a positive electrode and a negative electrode, and
A sheet-shaped laminated film outer body having a welded portion on the outer peripheral side while covering the electrode body,
With
The welded part is
A first welded portion that extends in the first direction in a plan view and welds a part of the outer peripheral side of the laminated film exterior body.
A second welded portion extending in a second direction intersecting the first direction in a plan view and welding a part of the outer peripheral side of the laminated film exterior body.
Have,
In a plan view, the second welded portion is formed so that the end portion of the second welded portion overlaps a part of the first welded portion without crossing the first welded portion in the second direction. have provided,
The first welded portion is
The welding main body extending in the first direction and
In a plan view, it has a welding protrusion that protrudes from the welding body in the second direction.
The second welded portion is an electrochemical element provided so that the tip portion in the second direction overlaps with the welded protruding portion in a plan view . In the electrochemical device according to claim 1,
One end side is connected to the electrode body, and the other end side is further provided with a positive electrode connection terminal and a negative electrode connection terminal extending outward from the laminated film outer body.
The first welding portion is an electrochemical element provided so as to include a portion of the laminate film outer body that sandwiches at least one of the positive electrode connection terminal and the negative electrode connection terminal. A method for manufacturing an electrochemical element, comprising: an electrode body including a positive electrode and a negative electrode, and a sheet-shaped laminated film outer body in which the outer peripheral side is welded while covering the electrode body.
With the electrode body covered with the laminated film outer body, a part of the outer peripheral side of the laminated film outer body is welded to form a first welded portion extending in the first direction in a plan view. Part formation process and
By welding a portion of the outer periphery of the laminate film casing body, and a second weld portion forming step of forming a second welded portion extending in a second direction intersecting the first direction in plan view,
Have,
In the second welding portion forming step, in a plan view, the end portion of the second welding portion overlaps with a part of the first welding portion without crossing the first welding portion in the second direction. The second welded portion is formed in
The first welded portion is
The welding main body extending in the first direction and
In a plan view, it has a welding protrusion that protrudes from the welding body in the second direction.
In the second welding portion forming step, a method for manufacturing an electrochemical element , in which the second welding portion is formed so that the end portion of the second welding portion overlaps with the welding protrusion in a plan view . In the method for manufacturing an electrochemical device according to claim 3,
In the first welding portion forming step, the laminating film exterior body is made by using a welding tool having a main body forming portion extending in the first direction and a protruding forming portion protruding from the main body forming portion in the second direction. A method for manufacturing an electrochemical element, which forms the first welded portion by welding a part of the outer peripheral side of the film. A manufacturing apparatus for manufacturing an electrochemical element including an electrode body including a positive electrode and a negative electrode, and a sheet-shaped laminated film outer body having a welded portion on the outer peripheral side while covering the electrode body.
Having a main body forming portion extending in the first direction and a protruding forming portion protruding in the second direction intersecting the first direction from the main body forming portion in a plan view, the laminated film outer body is sandwiched and heated. A pair of first welding tools for forming a first welding portion as a part of the welding portion on the laminated film outer body.
In a plan view, the laminated film is positioned so that the end portion in the second direction overlaps a part of the first welded portion without crossing the first welded portion in the second direction. A pair of second welding tools that form a second welding portion as a part of the welding portion on the laminated film outer body by sandwiching and heating the outer body.
A device for manufacturing an electrochemical element.

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