JP7165526B2 - electrochemical element - Google Patents

Description

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

An electrochemical device is known in which an electrode body including a positive electrode and a negative electrode is covered with a laminate film outer casing, and the outer peripheral side of the laminate film outer casing is welded.

For example, a battery disclosed in Patent Document 1 is known as an electrochemical device in which the electrode body is covered with a laminate film outer package as described above. The battery disclosed in Patent Literature 1 includes an electrode wound body in which a positive electrode and a negative electrode are laminated and wound with an electrolyte interposed therebetween, inside a film-like exterior member.

Patent Document 1 discloses a configuration in which a positive electrode lead is attached to the positive electrode, the portion where the positive electrode lead is attached is covered with an insulating coating material, and the region protruding from the positive electrode is covered with a resin coating material. .

Further, in Patent Document 1, the insulating coating material and the resin coating material partially overlap, and the overlapping part is provided in a region protruding from the positive electrode by extending the insulating coating material. It is disclosed that

Furthermore, Patent Document 1 discloses that the portion of the positive electrode lead covered with the resin coating material has one bent portion.

JP 2006-004777 A

The insulating coating material disclosed in the above-mentioned Patent Document 1 covers the positive electrode lead so as to partially overlap with the resin coating material. and the occurrence of a short circuit with the electrode winding body can be prevented.

By the way, in the case where the positive electrode lead is covered with an insulating coating material, there is a possibility that the insulating coating material is sandwiched by the outer packaging member at the portion where the outer packaging member of the laminate film is welded with the positive electrode lead sandwiched therebetween. be. The insulating coating material has poor weldability with the exterior member. Therefore, in the welded portion of the exterior member, there is a possibility that the sealing performance of the portion where the insulating coating material is sandwiched between the exterior members may deteriorate.

Therefore, when the positive electrode lead is covered with the insulating coating material as described above, damage to the positive electrode lead and occurrence of a short circuit can be prevented. The sealing performance of the material deteriorates.

An object of the present invention is to provide an electrochemical element in which an electrode body is covered with a laminate film outer package, and to provide a configuration that can prevent deterioration of the sealing performance of the laminate film outer package while preventing damage and short-circuiting of the positive electrode lead. It's about getting

A laminate type battery according to one embodiment of the present invention includes an electrode body including a positive electrode, a negative electrode, and a separator, a positive electrode connection terminal connected to the positive electrode and extending outward from the electrode body, and a terminal connected to the negative electrode. a sheet-like laminate film outer packaging body having a negative electrode connecting terminal extending outward from the electrode body, and a welded portion on the outer peripheral side while covering the electrode body while sandwiching the positive electrode connecting terminal and the negative electrode connecting terminal; and a seal member positioned between the positive electrode connection terminal and the laminate film exterior body and between the negative electrode connection terminal and the laminate film exterior body at the welded portion, the positive electrode connection terminal and and an insulating member having electrical insulation that covers each of the negative electrode connection terminals. The positive electrode connecting terminal and the sealing member have a plurality of bent portions inside the laminate film exterior body. The insulating member covers a portion of the sealing member on the electrode assembly side. The sealing member has an insulating member covering portion covered by the insulating member, and a laminate film outer body welded portion sandwiched between the laminate film outer body and the welded portion of the laminate film outer body (first configuration ).

The above configuration can prevent the insulating member from covering the portion of the sealing member to be welded to the laminate film outer casing. That is, since the positive electrode connecting terminal and the sealing member have a plurality of bent portions inside the laminate film exterior body, when the insulating member covers a part of the sealing member on the electrode body side, the Positioning of the insulating member can be easily performed. Thereby, the insulating member can be prevented from covering a portion of the sealing member other than the insulating member covering portion.

Thereby, the insulating member can be prevented from being sandwiched between the sealing member and the laminate film outer package at the welded portion of the laminate film outer package. Therefore, it is possible to prevent deterioration of the sealing performance of the welded portion.

Further, by covering the positive electrode connecting terminal and part of the sealing member with the insulating member as described above, it is possible to prevent damage to the positive electrode connecting terminal and occurrence of a short circuit.

Therefore, with the above-described configuration, it is possible to prevent damage to the positive electrode connection terminal and occurrence of a short circuit, and prevent deterioration of the sealability of the laminate film exterior body.

In the first configuration, the negative electrode connection terminal and the sealing member have a plurality of bent portions inside the laminate film exterior body (second configuration). As a result, like the positive electrode connection terminal, the negative electrode connection terminal can be prevented from being damaged and short-circuited, and the deterioration of the sealability of the laminate film exterior body can be prevented.

In the first or second configuration, the plurality of bent portions in the positive electrode connection terminal and the sealing member have two bent portions inside the laminate film outer package and are bent in a crank shape. (third configuration).

As a result, the positive electrode connection terminal and the sealing member can be compactly arranged inside the laminate film outer package, and the insulating member can be positioned more reliably with respect to the sealing member. Therefore, it is possible to realize a compact configuration that can prevent damage to the positive electrode connection terminal and occurrence of a short circuit and also prevent deterioration of the sealing performance of the laminate film exterior body.

In the second configuration, the plurality of bent portions of the negative electrode connection terminal and the seal member have two bent portions inside the laminate film exterior body and are bent in a crank shape (second 4).

As a result, the negative electrode connecting terminal and the sealing member can be compactly arranged inside the laminate film outer package, and the insulating member can be positioned more reliably with respect to the sealing member. Therefore, it is possible to realize a compact configuration that can prevent damage to the negative electrode connection terminal and occurrence of a short circuit, and also prevent deterioration of the sealing performance of the laminate film exterior body.

In any one of the first to fourth configurations, each of the positive electrode, the negative electrode, and the separator is strip-shaped. The electrode body is a wound electrode body in which the positive electrode, the negative electrode, and the separator are wound in a state in which the separator is positioned between the positive electrode and the negative electrode (fifth configuration).

Thus, when the electrode body is a wound electrode body, the positive electrode connection terminal and the sealing member have a plurality of bent portions inside the laminate film exterior body and outside the wound electrode body. Therefore, when the sealing member is partially covered with the insulating member, the insulating member can be easily positioned. Therefore, with the above-described configuration, it is possible to more reliably obtain a configuration that can prevent damage to the positive electrode connection terminal and occurrence of a short circuit, and also prevent deterioration of the sealing performance of the laminate film exterior body.

In the fifth configuration, the positive electrode connection terminal is connected to the winding start side of the wound electrode body (sixth configuration). In such a configuration, the positive electrode connection terminal and the sealing member connected to the wound electrode body have a plurality of bent portions inside the laminate film exterior body. Therefore, when a portion of the sealing member is covered with an insulating member, the insulating member can be easily positioned. Therefore, with the above-described configuration, it is possible to more reliably obtain a configuration that can prevent damage to the positive electrode connection terminal and occurrence of a short circuit, and also prevent deterioration of the sealing performance of the laminate film exterior body.

According to the electrochemical device according to one embodiment of the present invention, the positive electrode connection terminal connected to the positive electrode, and the welded portion of the laminate film outer casing positioned between the positive electrode connection terminal and the laminate film outer casing. The seal member has a plurality of bent portions inside the laminate film exterior body. The sealing member has an insulating member covering portion covered with an insulating member on a part of the electrode body side, and a laminate film outer body welded portion sandwiched between the laminate film outer bodies at the welding portion. As a result, it is possible to prevent damage to the positive electrode connection terminal and occurrence of a short circuit, and prevent deterioration of the sealability of the laminate film exterior body.

FIG. 1 is a perspective view showing a schematic configuration of a laminate type battery according to an embodiment. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a cross-sectional view taken along line III-III of FIG. FIG. 4 is a perspective view showing a schematic configuration of an electrode body. FIG. 5 is a diagram schematically showing a state in which a positive electrode, a negative electrode, and a separator are stacked in the thickness direction. FIG. 6 is a view equivalent to FIG. 2 of a laminate type battery according to another embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same reference numerals are given to the same or corresponding parts in the drawings, and the description thereof will not be repeated.

(overall structure)
FIG. 1 is a perspective view showing a schematic configuration of a laminate type battery 1 according to an embodiment of the invention. 2 and 3 are cross-sectional views showing a schematic configuration of the laminate type battery 1. FIG. This laminate type battery 1 is a rectangular secondary battery in a plan view in which an electrode body 10 functioning as a power generating body is covered with a laminate film exterior body 20 . 2, illustration of part of the electrode body 10 is omitted.

As shown in FIGS. 1 to 3 , the laminate type battery 1 includes an electrode body 10 and a laminate film exterior body 20 covering the electrode body 10 . The laminate type battery 1 also includes a positive electrode connection terminal 41 and a negative electrode connection terminal 42 electrically connected to the positive electrode 11 and the negative electrode 12 of the electrode assembly 10, respectively. A non-aqueous electrolyte is also sealed inside the laminate type battery 1 .

The laminate film exterior body 20 is made of a sheet-like material in which one surface side of an aluminum metal foil is covered with nylon and the other surface side is covered with polypropylene. In other words, the laminated film exterior body 20 is made of a material obtained by laminating aluminum with nylon and polypropylene.

The laminated film outer packaging 20 is welded by applying pressure while heating in a state where the polypropylenes of the laminated film outer packaging 20 are overlapped. That is, since the polypropylene of the laminate film exterior body 20 melts when heated, the polypropylene of the laminate film exterior body 20 is heated in a state where the polypropylene of the laminate film exterior body 20 is overlapped with each other as described above, and then cooled. can be welded.

The laminate film exterior body 20 is formed in a substantially rectangular shape. In a state in which the electrode body 10 is sandwiched between a pair of laminate film outer casings 20, the outer peripheral sides of the laminate film outer casings 20 are welded together to form the bulging portion 1a and the welded portion 1b as shown in FIGS. is formed. That is, the laminate film outer body 20 covers the electrode body 10 to form the bulging portion 1a, and the laminate film outer bodies 20 are welded together around the bulging portion 1a so as to surround the bulging portion 1a. Part 1b is formed.

As will be described later, in this embodiment, the electrode body 10 is formed by flattening a cylindrical wound electrode body. 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 of the laminate film exterior body 20 (hereinafter also simply referred to as a plan view). The welded portion 1b is formed around the bulging portion 1a so that the laminate battery 1 has a rectangular shape in plan view.

Moreover, as shown in FIGS. 2 and 3, the pair of laminated film outer bodies 20 has a flat portion 1c on one side of the electrode body 10 in the thickness direction of the electrode body 10. The outer peripheral sides of the laminate film exterior body 20 are welded to each other with the electrode body 10 sandwiched therebetween so that the other side of the laminate film exterior body 20 has the bulging portion 1a. That is, one of the pair of laminated film outer bodies 20 is arranged so as to follow the outer shape of the electrode body 10 .

In a portion of the welded portion 1b located on the end portion side in the longitudinal direction of the laminate type battery 1, a positive electrode connection terminal 41 and a negative electrode connection terminal 42, which will be described later, are sandwiched between a pair of laminate film exterior bodies 20. The laminate film exterior bodies 20 are fixed by being welded together.

In this embodiment, the outer peripheral sides of the pair of laminate film outer bodies 20 are welded together, but this is not the only option, and one laminate film outer body is folded back so as to sandwich the electrode body 10 and then welded. may be The direction in which the laminate film exterior body is folded may be the extending direction of the positive electrode connection terminal 41 and the negative electrode connection terminal 42 with respect to the electrode assembly 10, or may be the width direction.

(electrode body)
In the following description, the winding axial direction of the electrode assembly 10 means the direction along the axis L shown in FIG. Moreover, the minor axis direction of the electrode body 10 means the direction in which the diameter of the electrode body 10 is the smallest when viewed from the winding axis direction. The longitudinal direction of the electrode body 10 means the direction in which the diameter of the electrode body 10 is the largest when the electrode body 10 is viewed from the winding axis direction.

As shown in FIG. 4, the electrode body 10 is a flat wound electrode body formed in an elliptical shape when viewed from the winding axis direction. The electrode body 10 is formed by winding a strip-shaped positive electrode 11 and a strip-shaped negative electrode 12 in such a manner that a strip-shaped separator 13 is positioned between them and below the positive electrode 11, and then crushed. It is formed in a flat shape by being pressed. The flat electrode body 10 is accommodated in the space formed by the laminate film exterior body 20 .

FIG. 5 schematically shows how the electrode body 10 is formed. As shown in FIG. 5, the positive electrode 11, the negative electrode 12 and the separator 13 are stacked in the thickness direction in the order of the negative electrode 12, the separator 13, the positive electrode 11 and the separator 13 from above. In this state, by winding the positive electrode 11, the negative electrode 12 and the separator 13 in the direction of the white arrow in FIG.

In FIG. 5, the positions of the positive electrode 11, the negative electrode 12, and the separator 13 are shifted from their actual positions and shown obliquely in order to illustrate the state in which the positive electrode 11, the negative electrode 12, and the separator 13 are superimposed. In FIG. 5, in order to distinguish between the positive electrode 11, the negative electrode 12 and the separator 13, the positive electrode active material layer 11b of the positive electrode 11 and the negative electrode active material layer 12b of the negative electrode 12 are hatched although they are not cross sections.

After the cylindrical electrode body is obtained as described above, the cylindrical electrode body is radially crushed to obtain a flat electrode body 10 as shown in FIG. That is, the electrode body 10 is a wound electrode body in which the positive electrode 11 , the negative electrode 12 , and the separator 13 are stacked in such a manner that the separator 13 is positioned between the positive electrode 11 and the negative electrode 12 .

As shown in FIG. 5, the positive electrode 11 includes a positive electrode current collector 11a made of a metal foil such as aluminum, and a positive electrode active material layer 11b containing a positive electrode active material and provided on both sides of the positive electrode current collector 11a. have Specifically, the positive electrode 11 is formed by applying a positive electrode mixture containing a positive electrode active material, which is a lithium-containing oxide capable of intercalating and deintercalating lithium ions, a conductive agent, a binder, and the like, on a positive electrode current collector 11a made of aluminum foil or the like. It is formed by coating and drying. Examples of the lithium-containing oxide that is the positive electrode active material include lithium cobalt oxides such as LiCoO ₂ , lithium manganese oxides such as LiMn ₂ O ₄ , and lithium composite oxides such as lithium nickel oxides such as LiNiO ₂ . is preferred. As the positive electrode active material, only one kind of substance may be used, or two or more kinds of substances may be used. Moreover, the positive electrode active material is not limited to the above substances.

As shown in FIG. 5, the positive electrode 11 has positive electrode current collector exposed portions 11c and 11d, on both sides of which the positive electrode active material layer 11b is not provided, at both ends in the longitudinal direction of the positive electrode current collector 11a. That is, the positive electrode current collector exposed portion 11c is positioned on one side of the positive electrode 11 in the longitudinal direction, and the positive electrode current collector exposed portion 11d is positioned on the other side of the positive electrode 11 in the longitudinal direction. In the electrode body 10 of the present embodiment, the positive electrode current collector exposed portion 11c is located on the winding start side of the electrode body 10 (inside the electrode body 10), and the positive electrode current collector exposed portion 11d is located on the winding start side of the electrode body 10. It is positioned on the end side (the outermost peripheral side of the electrode assembly 10).

The negative electrode 12 includes a negative electrode current collector 12a made of metal foil such as copper, and negative electrode active material layers 12b containing a negative electrode active material and provided on both sides of the negative electrode current collector 12a. Specifically, for the negative electrode 12, a negative electrode mixture containing a negative electrode active material capable of intercalating and deintercalating lithium ions, a conductive aid, a binder, and the like is applied onto the negative electrode current collector 12a made of copper foil or the like, and then dried. formed by As the negative electrode active material, for example, it is preferable to use a carbon material capable of intercalating and deintercalating lithium ions (graphites, pyrolytic carbons, cokes, vitreous carbons, etc.). The negative electrode active material is not limited to the above substances.

As shown in FIG. 5, like the positive electrode 11, the negative electrode 12 also has negative electrode current collector exposed portions 12c and 12d at both ends in the longitudinal direction of the negative electrode current collector 12a. have. That is, the negative electrode current collector exposed portion 12c is located on one side of the negative electrode 12 in the longitudinal direction, and the negative electrode current collector exposed portion 12d is located on the other side of the negative electrode 12 in the longitudinal direction. In the electrode body 10 of the present embodiment, the negative electrode current collector exposed portion 12c is located on the winding start side of the electrode body 10 (inside the electrode body 10), and the negative electrode current collector exposed portion 12d is located on the winding start side of the electrode body 10. It is positioned on the end side (the outermost peripheral side of the electrode assembly 10).

A positive electrode connection terminal 41 is connected to the positive electrode current collector exposed portion 11c located on the winding start side of the electrode assembly 10 in the positive electrode 11 . A negative electrode connecting terminal 42 is connected to the negative electrode current collector exposed portion 12c located on the winding start side of the electrode body 10 in the negative electrode 12 . That is, the positive connection terminal 41 and the negative connection terminal 42 are connected to the winding start side of the electrode body 10 . The positive electrode connection terminal 41 and the negative electrode connection terminal 42 extend outward from the electrode body 10 and also extend outward from the laminate film exterior body 20 .

(Positive connecting terminal and negative connecting terminal)
Next, the configurations of the positive electrode connection terminal 41 and the negative electrode connection terminal 42 will be described in detail with reference to FIGS. 1 to 4. FIG.

The positive electrode connection terminal 41 is made of an aluminum metal foil having a rectangular shape in a plan view. One longitudinal side of the positive electrode connection terminal 41 is connected to the positive electrode current collector exposed portion 11c of the positive electrode 11 by welding, and the other longitudinal side of the positive electrode connection terminal 41 is positioned outside the laminate film exterior body 20 (FIG. 1). and FIG. 2). That is, the positive electrode connection terminal 41 is sandwiched between the laminate film outer casings 20 and extends outward from the inner side of the laminated film outer casing 20 .

The negative electrode connection terminal 42 is made of metal foil such as copper or nickel and is rectangular in plan view. One longitudinal side of the negative electrode connection terminal 42 is connected to the negative electrode current collector exposed portion 12c of the negative electrode 12 by welding, and the other longitudinal side of the negative electrode connection terminal 42 is located outside the laminate film outer package 20 (FIG. 1). and FIG. 3). That is, the negative electrode connection terminal 42 is sandwiched between the laminate film outer casings 20 and extends from the inside to the outside of the laminate film outer casing 20 .

By using the positive electrode connection terminal 41 and the negative electrode connection terminal 42 having the configuration as described above in the laminate type battery 1, the impedance can be reduced compared to the configuration in which the connection terminals are led out to the outside through other connection parts. can.

As shown in FIGS. 1 to 3, on the surface of the positive electrode connection terminal 41 and the negative electrode connection terminal 42, a positive electrode side sealing member 45 and a negative electrode side sealing member 46 are respectively sandwiched between the laminated film outer packagings 20. formed. That is, the positive electrode side sealing member 45 is positioned between the laminate film outer packaging 20 and the positive electrode connection terminal 41 , and the negative electrode side sealing member 46 is positioned between the laminate film outer packaging 20 and the negative electrode connection terminal 42 . The positive electrode side sealing member 45 and the negative electrode side sealing member 46 respectively correspond to sealing members.

The positive electrode side sealing member 45 and the negative electrode side sealing member 46 are each formed of a rectangular sheet in plan view made of a resin material such as polypropylene (PP). The sheet is arranged to extend along the positive electrode connection terminal 41 and the negative electrode connection terminal 42 and sandwich the positive electrode connection terminal 41 and the negative electrode connection terminal 42 , respectively. A positive electrode side sealing member 45 and a negative electrode side sealing member 46 are formed by coating the surfaces.

As a result, the adhesive strength between the laminate film outer package 20 and the positive electrode connection terminal 41 and the negative electrode connection terminal 42 sandwiched between the laminate film package 20 and the positive electrode connection terminal 41 and the negative electrode connection terminal 42 can be improved. Electrical insulation from the laminate film exterior body 20 can be ensured.

The positive electrode connection terminal 41 and the positive electrode side sealing member 45 have a positive electrode side first bent portion 51a and a positive electrode side second bent portion 51b bent in the thickness direction at the portion where the positive electrode connection terminal 41 is covered with the positive electrode side sealing member 45. have The positive electrode-side first bent portion 51 a and the positive electrode-side second bent portion 51 b are provided side by side in the longitudinal direction of the positive electrode connection terminal 41 and the positive electrode-side sealing member 45 . The positive electrode-side first bent portion 51 a and the positive electrode-side second bent portion 51 b are positioned inside the laminate film exterior body 20 . The positive electrode first bent portion 51a and the positive electrode second bent portion 51b correspond to the positive electrode first bent portion 51a and the positive electrode first bent portion 51a and the positive electrode seal member 45 in the positive electrode connection terminal 41 and the positive electrode seal member 45 when viewed in cross section in the extension direction of the positive electrode connection terminal 41 . It is formed so that the smaller of the angles formed by the portion between the side second bent portions 51b and the positive electrode current collector 11a becomes the predetermined angle α. The positive electrode side first bent portion 51a and the positive electrode side second bent portion 51b respectively correspond to bent portions.

As described above, the positive electrode connection terminal 41 is connected to the winding start side of the electrode body 10 in the positive electrode 11 . Therefore, the positive electrode first bent portion 51 a is positioned on the electrode body 10 side of the positive electrode connection terminal 41 and the positive electrode sealing member 45 and is bent in the direction of the minor axis of the electrode body 10 . The positive electrode-side second bent portion 51b is positioned closer to the leading end side (the other side in the longitudinal direction) of the positive electrode connection terminal 41 than the positive electrode-side first bent portion 51a and is bent in the winding axial direction of the electrode body 10. ing. That is, the positive electrode connection terminal 41 and the positive electrode side sealing member 45 are bent in a crank shape so as to approach the flat portion 1c of the laminate type battery 1 when viewed from the longitudinal direction of the electrode assembly 10 .

In addition, the positive electrode connection terminal 41 and the positive electrode side sealing member 45 include, in order from the electrode body 10 side, a positive electrode side insulating member covering portion 51c (insulating member covering portion) and a positive electrode side laminate film outer body welded portion 51d (laminate film outer casing). body welding part). The positive electrode-side insulating member covering portion 51c is located between the electrode body 10 and the positive electrode-side first bent portion 51a, and is covered with a positive electrode-side insulating member 55 which will be described later. The positive electrode side laminated film outer body welded portion 51d is positioned on the positive electrode side sealing member 45 on the leading end side in the extending direction of the positive electrode connection terminal 41 (the other side in the longitudinal direction) from the positive electrode side second bent portion 51b. The welded portion 1b of the battery 1 is sandwiched by the laminate film exterior body 20 .

The positive electrode-side first bent portion 51 a and the positive electrode-side second bent portion 51 b are formed by welding the positive electrode connection terminal 41 to which the positive electrode-side seal member 45 is attached to the positive electrode 11 , and then bending the positive electrode connection terminal 41 and the positive electrode-side seal member 45 together. formed in

The positive electrode side insulating member covering portion 51c of the positive electrode connection terminal 41 and the positive electrode side sealing member 45 is covered with a positive electrode side insulating member 55 (insulating member). That is, the positive electrode-side insulating member 55 covers a portion of the positive electrode-side insulating member covering portion 51c where the positive electrode connecting terminal 41 is exposed and a portion of the positive electrode-side sealing member 45 on the electrode body 10 side. In addition, the positive electrode side insulating member 55 is configured by, for example, a tape made of a resin material such as PP having electrical insulation.

Accordingly, it is possible to prevent the positive connecting terminal 41 from being cut off from the end portion of the positive electrode sealing member 45 on the electrode body 10 side due to the dropping of the laminate type battery 1 or the like. That is, damage to the positive electrode connection terminal 41 can be prevented by the positive electrode side insulating member covering portion 51c. In addition, by covering the exposed portion of the positive electrode connection terminal 41 in the positive electrode side insulating member covering portion 51c with the positive electrode side insulating member 55, the positive electrode connection terminal 41 is prevented from short-circuiting between the negative electrode 12 and the negative electrode connection terminal 42. can be prevented.

As described above, the portion where the positive electrode connection terminal 41 is covered with the positive electrode sealing member 45 has a plurality (two in this embodiment) of the positive electrode side first bent portions 51a and the positive electrode side second bent portions 51b. Thus, the positive electrode connecting terminal 41 and the positive electrode sealing member 45 can be provided with the positive electrode side insulating member covering portion 51c and the positive electrode side laminate film outer body welding portion 51d. Thereby, in the positive electrode connection terminal 41 and the positive electrode side sealing member 45, the portion covered by the positive electrode side insulating member 55 and the portion sandwiched by the laminate film outer packaging 20 can be separated.

Therefore, when covering the positive connecting terminal 41 and the positive sealing member 45 with the positive insulating member 55 , the positive insulating member 55 can be accurately positioned with respect to the positive connecting terminal 41 and the positive sealing member 45 . Therefore, the positive electrode-side insulating member 55 can more reliably cover a portion of the positive electrode-side sealing member 45 on the electrode body 10 side and prevent the positive electrode-side insulating member 55 from being sandwiched between the laminate film outer packaging 20. can. As a result, damage to the positive electrode connection terminal 41 and occurrence of a short circuit can be prevented, and deterioration of the sealability of the laminate film exterior body 20 can be prevented.

Similarly to the positive electrode connection terminal 41 and the positive electrode side seal member 45, the negative electrode connection terminal 42 and the negative electrode side seal member 46 are bent in the thickness direction at the portion where the negative electrode connection terminal 42 is covered with the negative electrode side seal member 46. It has a first bent portion 52a and a negative electrode side second bent portion 52b. The negative electrode first bent portion 52a and the negative electrode second bent portion 52b are provided side by side in the longitudinal direction of the negative electrode connection terminal 42 and the negative electrode seal member 46, respectively. The negative electrode-side first bent portion 52 a and the negative electrode-side second bent portion 52 b are positioned inside the laminate film exterior body 20 . The negative electrode first bent portion 52a and the negative electrode second bent portion 52b correspond to the negative electrode first bent portion 52a and the negative electrode first bent portion 52a and the negative electrode seal member 46 of the negative electrode connection terminal 42 and the negative electrode seal member 46 when viewed in cross section in the extension direction of the negative electrode connection terminal 42 . The smaller angle between the portion between the side second bent portions 52b and the negative electrode current collector 12a is formed to be the predetermined angle β. In addition, the negative electrode side first bent portion 52a and the negative electrode side second bent portion 52b respectively correspond to bent portions.

As described above, the negative electrode connection terminal 42 is also connected to the winding start side of the electrode body 10 of the negative electrode 12 , like the positive electrode connection terminal 41 . Therefore, the negative electrode side first bent portion 52 a is positioned on the electrode body 10 side of the negative electrode connecting terminal 42 and the negative electrode side seal member 46 and is bent in the minor axis direction of the electrode body 10 . The negative electrode side second bent portion 52b is positioned on the leading end side (the other side in the longitudinal direction) of the negative electrode connection terminal 42 in the extending direction of the negative electrode side first bent portion 52a and is bent in the winding axial direction of the electrode body 10. ing. That is, the negative connecting terminal 42 and the negative sealing member 46 are bent in a crank shape so as to approach the flat portion 1 c of the laminate type battery 1 when viewed from the longitudinal direction of the electrode assembly 10 .

Similarly to the positive electrode connection terminal 41 and the positive electrode side sealing member 45, the negative electrode connecting terminal 42 and the negative electrode side sealing member 46 also have a negative electrode side insulating member covering portion 52c (insulating member covering portion) and a negative electrode side insulating member covering portion 52c (insulating member covering portion) in this order from the electrode body 10 side. and a side laminate film outer body welded portion 52d (laminate film outer body welded portion). The negative electrode-side insulating member covering portion 52c is located between the electrode body 10 and the negative electrode-side first bent portion 52a, and is covered with a negative electrode-side insulating member 56 described later. The negative electrode-side laminate film outer body welded portion 52d is positioned on the negative electrode-side sealing member 46 on the distal end side of the negative electrode connecting terminal 42 in the extending direction (the other side in the longitudinal direction) of the negative electrode-side second bent portion 52b. The welded portion 1b of the battery 1 is sandwiched by the laminate film exterior body 20 .

The negative electrode side first bent portion 52a and the negative electrode side second bent portion 52b are also connected to the negative electrode connection terminal 42 to which the negative electrode side sealing member 46 is attached, similarly to the positive electrode side first bent portion 51a and the positive electrode side second bent portion 51b. is welded to the negative electrode 12 , the negative electrode connecting terminal 42 and the negative electrode side sealing member 46 are formed.

The negative electrode side insulating member covering portion 52c of the negative electrode connecting terminal 42 and the negative electrode side sealing member 46 is also covered with the negative electrode side insulating member 56 (insulating member), similarly to the positive electrode connecting terminal 41 and the positive electrode side sealing member 45 . That is, the negative electrode-side insulating member 56 covers a portion of the negative electrode-side insulating member covering portion 52c where the negative electrode connecting terminal 42 is exposed and a portion of the negative electrode-side sealing member 46 on the electrode body 10 side. The negative electrode side insulating member 56 is made of, for example, a tape containing an electrically insulating resin material such as PP.

Thus, it is possible to prevent the negative electrode connection terminal 42 from being cut off from the end portion of the negative electrode seal member 46 on the electrode assembly 10 side due to the dropping of the laminate type battery 1 or the like. That is, the negative electrode side insulating member covering portion 52c can prevent the negative electrode connection terminal 42 from being damaged. In addition, by covering the exposed portion of the negative electrode connection terminal 42 in the negative electrode side insulating member covering portion 52c with the negative electrode side insulating member 56, the negative electrode connection terminal 42 is prevented from short-circuiting between the positive electrode 11 and the positive electrode connection terminal 41. can be prevented.

As described above, the portion where the negative connection terminal 42 is covered with the negative seal member 46 has a plurality (two in the present embodiment) of the negative first bent portions 52a and the negative second bent portions 52b. As a result, the negative electrode connecting terminal 42 and the negative sealing member 46 can be provided with the negative electrode side insulating member covering portion 52c and the negative electrode side laminate film outer body welding portion 52d. As a result, the negative connecting terminal 42 and the negative sealing member 46 can be separated from the portion covered by the negative insulating member 56 and the portion sandwiched by the laminate film exterior body 20 .

Therefore, when covering the negative connecting terminal 42 and the negative sealing member 46 with the negative insulating member 56 , the negative insulating member 56 can be accurately positioned with respect to the negative connecting terminal 42 and the negative sealing member 46 . Therefore, the negative electrode-side insulating member 56 can more reliably cover a portion of the negative electrode-side sealing member 46 on the electrode body 10 side and prevent the negative electrode-side insulating member 56 from being sandwiched between the laminate film outer packaging 20 . can. As a result, damage to the negative electrode connection terminal 42 and occurrence of a short circuit can be prevented, and deterioration of the sealability of the laminate film exterior body 20 can be prevented.

(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, without being limited to the above-described embodiment, it is possible to modify the above-described embodiment as appropriate without departing from the spirit thereof.

In the above-described embodiment, the positive electrode connection terminal 41 and the positive electrode side sealing member 45 are provided at the portion where the positive electrode connection terminal 41 is covered with the positive electrode side sealing member 45, and the positive electrode side first bent portion 51a and the positive electrode side first bent portion 51a are bent in the thickness direction. It has a second bent portion 51b. However, the positive electrode connection terminal and the positive electrode side sealing member may have three or more bent portions.

In the above-described embodiment, the negative connecting terminal 42 and the negative sealing member 46 are bent in the thickness direction at the portion where the negative connecting terminal 42 is covered with the negative sealing member 46, and the negative electrode side first bent portion 52a is bent in the thickness direction. It has a second bent portion 52b. However, the negative connecting terminal and the negative sealing member may have three or more bent portions.

In the above-described embodiment, the negative connecting terminal 42 and the negative sealing member 46 are bent in the thickness direction at the portion where the negative connecting terminal 42 is covered with the negative sealing member 46, and the negative electrode side first bent portion 52a is bent in the thickness direction. It has a second bent portion 52b. However, the negative electrode connection terminal and the negative electrode side sealing member may not have the bent portion. That is, the bent portion may be provided only at the portion where the positive electrode connection terminal 41 having weak strength is covered with the positive electrode side sealing member 45 . A bent portion may be provided in a portion of the positive electrode connection terminal 41 that is not covered with the positive side sealing member 45 and a portion of the negative electrode connection terminal 42 that is not covered with the negative side sealing member 46 .

In the above-described embodiment, as shown in FIG. 2 , the positive electrode-side first bent portion 51 a and the positive electrode-side second bent portion 51 b are, when viewed in cross section in the extension direction of the positive electrode connection terminal 41 , the positive electrode connection terminal 41 and the positive electrode side seal. The positive electrode current collector 11a and the positive electrode current collector 11a are formed so that the smaller angle is the predetermined angle α. .

However, as shown in FIG. 6 , the positive electrode-side first bent portion 151 a and the positive electrode-side second bent portion 151 b are different from the positive electrode connection terminal 141 and the positive electrode seal member 145 when viewed in cross section in the extension direction of the positive electrode connection terminal 141 . Among the angles formed by the positive electrode current collector 11a and the portion between the positive electrode side first bent portion 151a and the positive electrode side second bent portion 151b, the positive electrode current collector 11a is formed so that the smaller angle α1 is smaller than the predetermined angle α. may be Reference numeral 101 in FIG. 6 denotes a laminated battery. In FIG. 6, the same reference numerals as in FIG. 2 indicate the same configurations as in FIG.

Although not shown in particular, similarly, the negative electrode side first bent portion and the negative electrode side second bent portion of the negative electrode connection terminal are also bent in the negative electrode side first bent portion of the negative electrode connection terminal and the negative electrode side sealing member in the thickness direction of the negative electrode connection terminal. and the portion between the negative electrode side second bent portions and the negative electrode current collector, the smaller angle may be smaller than the angle β shown in FIG.

In the above embodiment, the positive electrode side sealing member 45 and the negative electrode side sealing member 46 are made of a resin material such as PP. However, the positive electrode side sealing member and the negative electrode side sealing member may be made of any material as long as it can be welded to the laminate film exterior body.

In the above embodiment, the positive electrode side insulating member 55 and the negative electrode side insulating member 56 are made of a resin material such as PP. However, the positive electrode-side insulating member and the negative electrode-side insulating member may be made of any material as long as it is a material capable of preventing damage and short-circuiting of the positive electrode connection terminal and the negative electrode connection terminal. Moreover, the positive electrode side insulating member 55 and the negative electrode side insulating member 56 may be configured by a material other than the tape.

In the above embodiment, the positive electrode side sealing member 45 is formed on the surface of the positive electrode connection terminal 41 . However, the positive electrode-side sealing member 45 is a part or the entire surface of the positive electrode current collector exposed portion 11c, a welded portion between the positive electrode connection terminal 41 and the positive electrode current collector exposed portion 11c, or the welded portion of the positive electrode current collector 11a. It may be formed so as to cover the surface on the opposite side.

In the above embodiment, the negative electrode side sealing member 46 is formed on the surface of the negative electrode connection terminal 42 . However, the negative electrode-side sealing member 46 may be a part or the entire surface of the negative electrode current collector exposed portion 12c, a welded portion between the negative electrode connection terminal 42 and the negative electrode current collector exposed portion 12c, or the welded portion of the negative electrode current collector 12a. It may be formed so as to cover the surface on the opposite side.

In the above embodiment, the positive connection terminal 41 and the negative connection terminal 42 are connected to the winding start side of the electrode body 10 . However, at least one of the positive electrode connection terminal and the negative electrode connection terminal may be connected to a portion of the electrode body 10 other than the winding start side.

In the above-described embodiment, the electrode body 10 is a wound electrode body obtained by winding strip-shaped positive electrode 11, negative electrode 12, and separator 13 while stacking them in the thickness direction. However, the electrode body may be a laminated electrode body obtained by stacking sheet-like positive electrodes, negative electrodes, and separators in the thickness direction.

In the above-described embodiment, the laminated film exterior body 20 is made of a material obtained by laminating an aluminum metal foil with nylon and polypropylene. However, the metal foil of the laminate film exterior is not limited to aluminum, and may be made of other metal materials such as stainless steel. Also, any material may be used for the welded portion of the laminate film outer packaging as long as it melts when heated, hardens when cooled, and does not melt with a non-aqueous electrolyte. Furthermore, in the laminate film outer package, any material other than the welded portion may be used as long as it is a material that can be laminated with a metal foil.

In the above embodiment, the laminate type battery 1 is formed in a rectangular shape in plan view. However, the laminate type battery may have other shapes such as polygonal shape.

In the above embodiment, the laminate type battery 1 is a lithium ion battery. However, the laminate type battery 1 may be a battery other than the lithium ion battery. Moreover, the configuration of the above embodiment may be applied not only to a laminate type battery but also to an electrochemical device including a capacitor and the like. That is, the configuration of the above embodiment can be applied to an electrochemical element capable of storing or generating electricity and having connection terminals connected to electrode bodies extending outward from the laminate film exterior body.

INDUSTRIAL APPLICABILITY The present invention can be applied to a laminate type battery in which an electrode assembly is covered with a laminate film outer package.

1, 101 Laminated Battery (Electrochemical Device)
1a Swelling portion 1b Welded portion 10 Electrode body 11 Positive electrode 11a Positive electrode current collector 11b Positive electrode active material layers 11c, 11d Positive electrode current collector exposed portion 12 Negative electrode 12a Negative electrode current collector 12b Negative electrode active material layers 12c, 12d Negative electrode current collector Exposed portion 13 Separator 20 Laminate film exterior body 41, 141 Positive electrode connection terminal 42 Negative electrode connection terminal 45 Positive electrode side seal member (seal member)
46 negative electrode side sealing member (sealing member)
51a, 151a positive electrode side first bending portion (bending portion)
51b, 151b positive electrode side second bending portion (bending portion)
51c positive electrode side insulating member covering portion (insulating member covering portion)
51d Positive electrode side laminate film outer body welding part (laminate film outer body welding part)
52a Negative electrode side first bent portion (bent portion)
52b Negative electrode side second bent portion (bent portion)
52c Negative electrode side insulating member covering portion (insulating member covering portion)
52d Negative electrode-side laminate film exterior body welded portion (laminate film exterior body welded portion)
55 positive electrode side insulating member (insulating member)
56 Negative electrode side insulating member (insulating member)

Claims (6)

an electrode body including a positive electrode, a negative electrode and a separator;
a positive electrode connection terminal connected to the positive electrode and extending outward from the electrode body;
a negative electrode connection terminal connected to the negative electrode and extending outward from the electrode body;
a sheet-like laminate film exterior body having a welded portion on the outer peripheral side in a state of covering the electrode body while sandwiching the positive electrode connection terminal and the negative electrode connection terminal;
a sealing member positioned between the positive electrode connection terminal and the laminated film outer casing and between the negative electrode connection terminal and the laminated film outer casing at the welded portion;
an insulating member having electrical insulation covering the positive electrode connection terminal and the negative electrode connection terminal, respectively;
with
The positive electrode connecting terminal and the sealing member have a plurality of bent portions inside the laminate film outer package , including a first bent portion located on the electrode body side of the positive electrode connecting terminal and the sealing member ,
The insulating member covers a portion of the sealing member on the electrode body side,
The sealing member is
an insulating member covering portion positioned between the electrode body and the first bent portion and covered with the insulating member;
a laminate film outer body welded portion located on the leading end side in the extending direction of the positive electrode connection terminal relative to the first bent portion and sandwiched by the laminate film outer body at the welded portion of the laminate film outer body;
An electrochemical device having In the electrochemical device according to claim 1,
The electrochemical device, wherein the negative electrode connecting terminal and the sealing member have a plurality of bent portions inside the laminate film exterior body. In the electrochemical device according to claim 1 or 2,
The electrochemical device, wherein the plurality of bent portions in the positive electrode connection terminal and the seal member have two bent portions inside the laminate film exterior body and are bent in a crank shape. In the electrochemical device according to claim 2,
The electrochemical device, wherein the plurality of bent portions of the negative electrode connection terminal and the seal member have two bent portions inside the laminate film exterior body and are bent in a crank shape. In the electrochemical device according to any one of claims 1 to 4,
The positive electrode, the negative electrode and the separator are strip-shaped,
wherein the electrode body is a wound electrode body in which the positive electrode, the negative electrode, and the separator are wound while the positive electrode, the negative electrode, and the separator are stacked such that the separator is positioned between the positive electrode and the negative electrode; element. In the electrochemical device according to claim 5,
The positive electrode connection terminal is an electrochemical element connected to the winding start side of the wound electrode body.

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