JP2020202120A - Method for manufacturing electrode, electrode and electrode lamination structure, and electrochemical cell - Google Patents

Abstract

To provide an electrode that can be easily mass-produced.SOLUTION: A method for manufacturing an electrode of the present invention is a method for manufacturing an electrode in which a plurality of electrode body parts are connected in a belt shape with electrode connection parts therebetween and electrode terminal are formed on the electrode body parts on one side, the electrode with a laminated structure having an active material layer and a separator layer in which the electrode body parts and electrode connection parts are formed on a collector layer and on both sides thereof, and includes: applying the active material layer on both faces of a collector sheet, including approximately the entirety of an outer peripheral contour of the electrode within an application range of the active material, including a leading end of the electrode terminal in an unapplied part of the active material, forming a punching part for extending an extension part to an outer peripheral part of an electrode body on the other end side, forming a belt-like structure consisting of an electrode terminal corresponding part, an electrode body part corresponding part, and the extension part inside the punching part while supporting both ends with the electrode terminal corresponding part and the extension part, forming a coating for separator layer formation on a base end side of the electrode terminal corresponding part and both front and back faces of an electrode structure corresponding part and the extension part, and cutting at the leading end side of the electrode terminal corresponding part and the extension part.SELECTED DRAWING: Figure 7

Description

The present invention relates to a method for manufacturing an electrode, an electrode and an electrode laminated structure, and an electrolytic chemical cell.

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

For example, as a porous separator for a battery, Patent Document 1 below describes a step of printing a thin layer of a separator precursor on an electrode and a step of vulcanizing this thin layer to change it into a microporous composite separator structure. A manufacturing method comprising the above is disclosed.
In Patent Document 2 below, the voids between the polymer solid electrolyte obtained by impregnating the stretched porous PTFE (polytetrafluoroethylene) with a polymer solid electrolyte resin solution and then removing the solvent, and the stretched porous PTFE. A composite polymer solid electrolyte membrane / electrode integrally molded body in which an electrode catalyst and an electrode filled with an electrode component containing a polymer solid electrolyte are integrally molded is described.
Further, in recent years, in response to the demand for thinner wearable devices, a structure of an electrochemical cell having an electrode in which a band-shaped electrode and a band-shaped separator are laminated in a zigzag shape has been studied.

Japanese Unexamined Patent Publication No. 10-334877 Japanese Unexamined Patent Publication No. 08-329962

When manufacturing an electrode in which the above-mentioned strip-shaped separator and strip-shaped electrode are laminated in a zigzag shape, the manufacturing method described below can be examined.
As shown in FIG. 19, active material layers 101 for the positive electrode or the negative electrode are formed on both the front and back surfaces of the current collector sheet 100 made of a strip-shaped metal foil in a plan view, except for the rectangular uncoated region 100a on the upper part of the sheet. To do. After that, as shown in FIG. 20, when punching is performed so as to leave the punched portion 102 corresponding to the contour shape of the electrode so as to extend over the active material layer 101 and the uncoated region 100a, the electrode body with the active material layer shown in FIG. 21 is formed. 103 can be obtained.
Next, the electrode 106 having the configuration shown in FIG. 22 can be obtained by applying a paint to the electrode body 103 so as to cover the entire surface of the active material layer 101 to form the separator layer 105. The electrode 106 has a structure in which a plurality of circular electrode bodies 107 are connected in a band shape by a band-shaped electrode connecting portion 108, and the electrode terminal 109 protrudes from the electrode body 107 at the end.

If the manufacturing method described with reference to FIGS. 19 to 22 is carried out, when the paint is applied to the front surface and the back surface of the electrode body 103, the paint wraps around to the side surface side of the electrode body, so that the electrode body 107 and the electrode are connected. An electrode 106 having a structure in which the entire outer periphery of the portion 108 is covered with the separator layer 105 can be manufactured. Since the electrode 106 covers the entire outer periphery of the electrode body 107 and the electrode connection portion 108 with the separator layer 105, it is excellent in terms of insulation, but when the above-mentioned manufacturing method is adopted, the electrodes 106 are individually arranged one by one. It is considered that this is a manufacturing method that is not suitable for mass production because it must be produced.

Next, in the case of manufacturing an electrode in which the above-mentioned strip-shaped separator and strip-shaped electrode are laminated in a zigzag shape, as an example of a manufacturing method for improving productivity, the manufacturing method described below based on FIGS. It is conceivable to adopt it.
As shown in FIG. 23, active material layers 111 for the positive electrode or the negative electrode are formed on both the front and back surfaces of the strip-shaped current collector sheet 110 in a plan view, except for the rectangular region 110a above the current collector sheet 110. Then, as shown in FIG. 24, a paint is applied so as to cover the surface of the active material layer 111, and the paint is dried or cured to form the separator layer 112.

After forming the separator layer 112, punching is performed so as to leave a punched portion 114 corresponding to the contour shape of the electrode as shown in FIGS. 25 and 26, so that the positive electrode having the configuration shown in FIGS. 26 (A) and 26 (B) can be used. An electrode body 113 for a negative electrode can be obtained.
The electrode body 113 shown in FIG. 26 has a plan view structure in which a plurality of circular electrode bodies 113a are connected via a band-shaped electrode connecting portion 113b. In the electrode body 113, the active material layer 113d and the separator layer 113e are laminated on both the front and back sides of the current collector layer 113c punched out from the current collector sheet 110, and one end of the current collector layer 113c in the length direction. It has a structure in which a strip-shaped electrode terminal 113f is projected on the side.

A positive electrode body and a negative electrode body having the structure shown in FIG. 26 are prepared, and the electrode bodies 113a of these electrode bodies are alternately laminated and the electrode bodies are bent in a zigzag shape to obtain a target laminated electrode. Can be obtained.
According to the manufacturing method described with reference to FIGS. 23 to 26, by increasing the size of the current collector sheet 110 to be used, it is possible to manufacture a plurality of electrode bodies 113 by one punching, and a large amount of laminated electrodes can be manufactured. It has the advantage of being able to be produced.
However, in the electrode body 113 obtained by punching, the separator layer is not formed on the side surface side of the outer peripheral portion as shown in FIG. 26 (B), and the side surface portion of the current collector layer 113c is exposed. There is a problem. Here, for example, when the electrode body 113 is wound in a zigzag folding process or the like, if winding misalignment occurs, a short circuit may occur due to the exposed current collector layer 113c.

Next, as a manufacturing method that can avoid the possibility of short circuit due to the current collector layer 113c, the manufacturing method described below can be examined based on FIGS. 27 to 30.
As shown in FIG. 27, active material layers 111 for the positive electrode or the negative electrode are formed on both the front and back surfaces of the strip-shaped current collector sheet 110 in a plan view, except for the rectangular region 110a above the current collector sheet 110.
Next, as shown in FIG. 28, punching is performed into a shape close to the desired electrode contour shape. In FIG. 27, the peripheral portion of the current collector layer 115 punched out from the current collector sheet 110 is punched out and removed so as to leave the strip-shaped structure 115 in which the active material layer 113d is laminated on both the front and back sides of the current collector layer. ..

FIG. 28 shows a state in which two strip-shaped structures 115 are adjacent to each other on the left and right and punched around them, and a punched portion 116 is formed around the strip-shaped structure 115. At this time, the two strip-shaped structures 115 are arranged in parallel inside the punched portion 116 in a state of being cantilevered by the portion of the electrode terminal 113f.
Next, as shown in FIG. 29, a paint for forming a separator layer is applied to both the front and back surfaces of the strip-shaped structure 115 excluding the electrode terminal 113f, and the required portion of the strip-shaped structure 115 is removed by separating or curing the separator layer 117. It is possible to obtain the electrode body 118 shown in FIG. 30 having a structure covered with.
When applying the paint for creating the separator layer, if printing is performed by a conventional method such as a screen printing method, a doctor blade method, a dipping method, or a die coating method, the paint wraps around the side surface side of the strip-shaped structure 115, so that the strip-shaped structure 115 The entire necessary portion of the above can be covered with the separator layer 117. According to this manufacturing method, since the peripheral portion of the current collector layer is not exposed on the side surface side of the strip-shaped structure 115, it is considered that the electrode body 118 without a risk of short circuit can be manufactured.

However, in the manufacturing method described above, there is a problem that the strip-shaped structure 115 is extremely unstable because the strip-shaped structure 115 is in a cantilevered support state by the electrode terminals 113f in the punched state shown in FIG. 28.
For example, since the current collector sheet 110 constituting the electrode terminal 113f has a thickness of about 10 μm, it may be bent at the time of punching, and further, when an active material is applied on the current collector sheet, or In any case of applying the paint that is the base of the separator layer 117 on the active material layer, there is a possibility that the electrode terminal 113f may be bent, and a defective product may be manufactured.

The present invention has been made in view of the conventional circumstances as described above, and an object of the present invention is to provide an electrode manufacturing method and an electrode, an electrode structure, and an electrochemical cell that can reduce the occurrence rate of defective products in mass production. And.

(1) In order to solve the above problems, in the method for manufacturing an electrode according to one embodiment of the present invention, a plurality of electrode bodies are connected in a band shape via an electrode connecting portion to form an electrode structure, and an electrode body on one end side is formed. It is an electrode having an electrode terminal formed on the surface of the electrode, and is a method for manufacturing an electrode having a laminated structure in which the electrode structure has a current collector layer and an active material layer and a separator layer formed on both sides thereof. The active material layer is applied to the portion of the body sheet excluding the unapplied portion provided on both the front and back sides of the body sheet so that the coating range of the active material layer includes almost the entire outer contour of the electrode structure. An extension portion extends from the outer peripheral portion of the electrode body located on the other end side of the plurality of electrode bodies connected in a band shape so that the uncoated portion of the active material layer includes the tip end portion of the electrode terminal. By forming the punched portion so as to be ejected, a strip-shaped structure composed of the electrode terminal corresponding portion, the electrode structure corresponding portion, and the extending portion is formed inside the punched portion with the electrode terminal corresponding portion and the extending portion. It is formed with both ends supported by the protruding portion, and then an insulating coating film for forming a separator layer is formed on the base end side of the electrode terminal corresponding portion, the electrode structure corresponding portion, and both the front and back surfaces of the extending portion. After the insulating coating film is cured to form a separator layer, the electrode is obtained by cutting at the tip end side of the electrode terminal corresponding portion and the extending portion.

When a punched portion is formed on the current collector sheet to form a strip-shaped structure having an outline outline similar to the electrode structure, the strip-shaped structure is formed with both ends supported by the electrode terminal corresponding portion and the extending portion. Therefore, the insulating coating film for forming the separator layer can be formed in a state where the strip-shaped structure is stably supported. Therefore, an insulating coating film can be formed without causing defects such as bending in the strip-shaped structure, and a separator layer can be formed by curing the insulating coating film. Further, it is possible to obtain an electrode with a well-shaped separator layer that does not have a defective portion such as a bent portion.

(2) In the method for manufacturing an electrode according to an embodiment of the present invention, the collector is located on the end side opposite to the end side of the current collector sheet on which the uncoated portion of the active material layer is formed. After attaching the insulating layer covering the end face of the electric body sheet and the end portion of the active material layer adjacent to both sides of the end face,
The punched portion is formed so as to form the extension portion and the outer peripheral portion of the electrode body following the extension portion in the attachment range of the insulating layer, and then the insulation attached to the outer peripheral portion of the electrode body. It is preferable to obtain the electrode by cutting from the current collector sheet at the extending portion so as to leave a layer.

Since the insulating coating film is applied after forming the punched portion on the current collector sheet, the front and back surfaces and the side surfaces (outer peripheral surface) of the strip-shaped structure remaining after punching can be covered with the insulating coating film. The current collector layer inside the strip-shaped structure may be exposed at the portion to be cut after being covered with. However, if the insulating layers are provided on the front and back of the exposed portion, the exposed portion of the current collector layer can be surrounded by the insulating layer, so that an electrode having a low risk of short circuit can be manufactured.

(3) In the method for manufacturing an electrode according to an embodiment of the present invention, the active material layer is formed on the end side of the current collector sheet on the opposite side to the end side of the current collector sheet. When the uncoated portion of the material layer is partitioned and the punching is performed, the extending portion and a part of the electrode body following the extending portion are punched so as to be located in the uncoated portion, and the electrode When an electrode corresponding portion supported at both ends by a terminal corresponding portion and the extending portion is formed, and then an insulating coating film for forming the separator layer is formed, the insulating coating film is applied so as to include the uncoated portion. It is characterized in that it is formed, and then the insulating coating film is cured to form a separator layer.

In the previous embodiment of the present invention, the insulating layer is attached on the active material layer, but the portion where the insulating layer is stretched may be an uncoated part of the active material layer in advance. As a result, the separator layer can be arranged instead of the insulating layer in the portion where the insulating layer is stretched, and the electrode can be configured not to be thickened by the thickness of the insulating layer. Even if a gap is generated between the insulating layer and the electrode coated portion, if the separator layer is applied so as to cover the portion, the portion can be filled with the separator layer, and no structural problem occurs.

(4) In the method for manufacturing electrodes according to an embodiment of the present invention, a current collector sheet having a length and width capable of arranging a plurality of the electrodes in parallel with each other is used as the current collector sheet, and the current collector sheet is used. The uncoated portion of the active material layer is formed in a band shape on one side in the width direction orthogonal to the length direction of the sheet, and the tip end portion of the electrode terminal is positioned on the strip-shaped uncoated portion to position the current collector sheet. It is preferable to form a punched portion so that a plurality of the strip-shaped structures are lined up in the length direction of the above, and separate the plurality of strip-shaped structures from the current collector sheet to obtain a plurality of electrodes.

By punching a plurality of strip-shaped structures in parallel on the current collector sheet, a plurality of strip-shaped structures can be formed on one current collector sheet by one punching. After this punching, a plurality of strip-shaped structures can be cut out from the current collector sheet to manufacture a plurality of electrodes at the same time. Therefore, mass production of electrodes becomes possible.

(5) In the method for manufacturing an electrode according to an embodiment of the present invention, when the insulating layer is provided on the end side of the current collector sheet, the outside of the surface end side of the current collector sheet and the current collector. By attaching an insulating tape from the outside of the back surface end side of the body sheet, the end of the active material layer on the front surface end side of the current collector sheet, the end surface of the current collector sheet, and the current collector sheet. It is preferable to cover the end portion of the active material layer on the back surface end portion side with the insulating tape.

By attaching an insulating tape to form an insulating layer on the end side of the current collector sheet, the necessary portion of the strip-shaped structure generated after punching can be easily covered with the insulating layer. The current collector layer inside the strip-shaped structure may be exposed at the part to be cut after being covered with insulating tape, but if the area around this exposed part is covered with insulating tape, the area around the exposed part of the current collector layer will be exposed. Since it can be surrounded by a part of the insulating tape remaining after cutting, an electrode with a low risk of short circuit can be manufactured.

(6) The electrode according to one embodiment of the present invention is an electrode in which a plurality of electrode bodies are connected in a band shape via an electrode connecting portion to form an electrode structure, and an electrode terminal is formed on an electrode body on one end side. The electrode structure is an electrode having a laminated structure having a current collector layer and an active material layer and a separator layer formed on one or both sides thereof, and the outer peripheral surface of the electrode structure is a separator made of a coating film curing layer. Of the plurality of electrode bodies covered with layers, the electrode body on the other end side with respect to the electrode body on one end side provided with the electrode terminals, and on the active material layer on the outer periphery of the front and back surfaces of the electrode body. The unformed portion of the separator layer is formed, and the insulating layer is coated around the unformed portion.

When a laminated electrode is configured as a zigzag structure or a winding structure, there is a concern that the current collector layer inside the portion where the separator layer does not exist is exposed, but insulation is provided around the unformed portion of the separator layer. By arranging the layers, it is possible to provide a structure in which many insulating layers are arranged around the exposed portion of the current collector layer. Therefore, it is possible to provide an electrode having a low risk of internal short circuit.

(7) In the electrode according to one embodiment of the present invention, the insulating layer is made of an insulating tape, and the insulating tape causes an end face of the outer peripheral portion of the electrode body on the other end side and an end portion of the active material layer sandwiching the end face. It is preferably covered.

If the insulating tape is attached, it is possible to cover the portion required for insulation with an arbitrary width, and it is possible to provide an electrode with a low risk of internal short circuit.

(8) The electrode laminated structure according to one embodiment of the present invention is provided with a pair of electrodes according to (5) or (6), and the active material of one electrode is used as the positive electrode active material to form the positive electrode, and the other. The negative electrode is constructed by using the active material of the electrode as the negative electrode active material, and the positive electrode and the negative electrode are vertically folded by overlapping the electrode bodies on the side where the insulating layer is provided, and the positive electrode is folded in a zigzag manner. The electrode body of the electrode and the electrode body of the negative electrode are alternately laminated.

If the electrode laminated structure is provided with electrodes having a low risk of short-circuiting, it is possible to provide a battery in which short-circuiting does not occur internally even if the battery is configured by being housed in a container.

(9) The electrochemical cell according to one embodiment of the present invention is characterized in that the electrode laminated structure according to (7) is provided inside the exterior body.

In the present invention, when an electrode structure having an electrode body and an electrode connection portion and an electrode having an electrode terminal are manufactured, almost the entire outer contour of the electrode structure is covered in the coating range of the active material layer formed on the current collector sheet. A punched portion is formed so as to include the tip end portion of the electrode terminal in the uncoated portion of the active material layer and to leave an extending portion on the side opposite to the electrode terminal forming side. As a result, the strip-shaped structure can be formed in the punched portion with the electrode terminals and the extending portions supporting both ends. Therefore, an insulating coating film is formed so as to cover the strip-shaped structure, and then the both-end supporting portions are cut. By doing so, the target electrode can be manufactured. Since the strip-shaped structure supported at both ends can be stably supported in the punched portion, defects such as bending do not occur when the insulating coating film is applied.

The plan view which shows an example of the battery which provided the electrode of 1st Embodiment obtained by this invention. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. A unit in which a positive electrode and a negative electrode incorporated in the battery are superposed is shown, (A) is a perspective view, and (B) is a plan view. The plan view which shows the 1st Embodiment of the electrode obtained by this invention. The plan view which shows the state which applied the active material layer to the current collector sheet in the method of manufacturing the electrode of 1st Embodiment which concerns on this invention. FIG. 5 is a plan view showing a state in which a punched portion is formed on a current collector sheet with an active material layer in the same manufacturing method. FIG. 5 is a plan view showing a state in which a separator layer is formed on a current collector sheet having a punched portion formed in the same manufacturing method. The electrodes of the first embodiment obtained by the same manufacturing method are shown, (A) is a plan view, and (B) is a partial cross-sectional view. A plan view showing a state in which an active material layer is formed on a current collector sheet and an insulating layer made of an insulating tape is coated on the end side of the current collector sheet in the method for manufacturing an electrode according to the second embodiment of the present invention. .. Side view of the same state. The plan view which shows the state which formed the punching part in the current collector sheet of the same state. The plan view which shows the state which formed the separator layer on the current collector sheet which formed the punched part. The plan view which shows the electrode of the 2nd Embodiment separated from the current collector sheet. The plan view which shows the electrode of 3rd Embodiment. The plan view which shows the electrode of 4th Embodiment. In the method for manufacturing an electrode according to the fourth embodiment of the present invention, an active material layer is formed on the current collector sheet, an insulating tape is coated on the end side of the current collector sheet, and the current collector sheet in the same state is formed. The plan view which shows the state which formed the punched part. From the state shown in FIG. 16, a plan view showing a state in which a separator layer is formed on a current collector sheet. The perspective view which shows an example of the electrode laminated structure obtained by winding the electrode of 4th Embodiment together with other electrodes. It shows the first method which examined the manufacturing method of the electrode to be laminated in a zigzag shape, and is the top view which shows the state which formed the active material layer on the current collector sheet. The plan view which shows the state which formed the punching part in the 1st method. The electrode body punched in the first method is shown, (A) is a plan view, and (B) is a side view. An electrode obtained by forming an insulating coating film on the surface in the first method is shown, (A) is a plan view, and (B) is a sectional view. It shows the 2nd method which examined the manufacturing method of the electrode to be laminated in a zigzag shape, and is the top view which shows the state which formed the active material layer on the current collector sheet. The plan view which shows the state which formed the separator layer on the active material layer in the 2nd method. The plan view which shows the state which formed the punched part including the active material layer and the separator layer in the 2nd method. The electrode obtained by forming an insulating coating film on the surface in the second method is shown, (A) is a plan view, and (B) is a sectional view. It shows the 3rd method which examined the manufacturing method of the electrode to be laminated in a zigzag shape, and is the top view which shows the state which formed the active material layer on the current collector sheet. FIG. 3 is a plan view showing a state in which a punched portion is formed on a current collector sheet including an active material layer in the third method and a band-shaped structure is left. FIG. 5 is a plan view showing a state in which a separator layer is formed on a strip-shaped structure by coating in the third method. The plan view which shows the electrode cut and separated from the current collector sheet by the 3rd method. A partial cross-sectional view showing an example of a battery in which electrodes are housed in a laminated pack type container.

Hereinafter, embodiments of the electrodes according to the present invention will be described with reference to the drawings. In the following embodiment, a coin-type lithium ion secondary battery (hereinafter, simply referred to as “battery”) is given as an example of an electrochemical cell, and an electrode mounted on the battery will be described.
In the drawings used in the following description, the scale of each member is appropriately changed in order to make each member recognizable.

"First embodiment"
[battery]
As shown in FIG. 1, the battery 1 of the first embodiment has a circular shape in a plan view. With reference to FIG. 2, the battery 1 includes an electrode laminated structure 2 composed of a superposed unit 2A, an electrolyte solution (not shown) impregnated in the electrode laminated structure 2, and an exterior accommodating the electrode laminated structure 2. It has a body 10. The plan view shape of the battery 1 does not have to be circular, and various shapes such as an elliptical shape, a quadrangular shape, and a polygonal shape can be adopted. However, in the present embodiment, the plan view circular shape is used for simplification of the description. The coin-shaped battery 1 of the above will be described as an example.

[Electrode laminated structure]
As shown in FIG. 3A, the stacking unit 2A is folded into a spirally folded shape in a direction intersecting the negative electrode 3 and the negative electrode 3 so as to be alternately laminated with the negative electrode 3. The electrode structure (positive electrode structure) 4 is provided, and the electrode laminated structure 2 is composed of the stacking unit 2A.

[Negative electrode]
The negative electrode electrode 3 has a band shape when it is unfolded after the zigzag state is released. The negative electrode electrode 3 includes a plurality of electrode connecting portions 3a and a plurality of circular overhanging portions (electrode main bodies) 3b, similarly to the positive electrode electrode 5 described later.

As shown in FIG. 2, the negative electrode electrode 3 includes a negative electrode current collector 20 and a negative electrode active material layer 22 formed on both sides of the negative electrode current collector 20. As shown in FIG. 3A, an extending portion (negative electrode electrode terminal) 21 of the negative electrode current collector 20 is formed at one end of the negative electrode electrode 3. The negative electrode terminal 21 corresponds to a portion of the negative electrode current collector 20 extending outward from the electrode body 3b in the longitudinal direction of the negative electrode 3.

For example, the negative electrode current collector 20 is made of a metal material such as copper, nickel, and stainless steel. The negative electrode active material layer 22 contains a negative electrode active material, a conductive auxiliary agent, a binder, a thickener and the like. For example, the negative electrode active material layer 22 is made of a carbon material such as graphite. For example, examples of the conductive auxiliary agent include carbon blacks, carbon materials, and fine metal powders. For example, examples of the binder include resin materials such as polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR) and polytetrafluoroethylene (PTFE). For example, examples of the thickener include resin materials such as carboxymethyl cellulose (CMC).

[Electrode structure (positive electrode structure)]
As shown in FIG. 4, the electrode structure (positive electrode structure) 4 includes a positive electrode electrode 5 and a separator layer 6 that covers almost the entire positive electrode electrode 5. The electrode structure 4 of the present embodiment integrates the positive electrode 5 and the separator layer 6. The general shape of the electrode structure 4 is substantially the same size as the general shape of the negative electrode electrode 3.

[Positive electrode]
The positive electrode 5 has a strip shape when it is unfolded after the zigzag state is released. Specifically, the positive electrode electrode 5 includes a plurality of electrode connecting portions 5a and a plurality of electrode bodies 5b. Hereinafter, the direction orthogonal to the longitudinal direction of the strip-shaped positive electrode 5 may be referred to as the “width direction of the positive electrode 5”. The electrode connecting portion 5a is recessed inward in the width direction of the positive electrode 5.
As shown in FIG. 4, in the expanded state of the positive electrode electrode 5, the electrode body 5b is arranged at a position adjacent to the electrode connecting portion 5a in the longitudinal direction of the positive electrode electrode 5. The electrode body 5b projects in an arc shape outward from the electrode connection portion 5a in the width direction of the positive electrode electrode 5. The electrode body 5b in the deployed state in this embodiment has a circular shape and is connected in a straight line through four electrode connecting portions 5a.

As shown in FIG. 3, in the zigzag structure of the electrode structure 4, the electrode bodies 5b are arranged substantially parallel to each other. The electrode connecting portion 5a is connected to the edge of each electrode body 5b in the longitudinal direction of the positive electrode electrode 5. That is, the electrode connecting portion 5a connects two adjacent electrode bodies 5b in series.

With reference to FIGS. 3 and 4, the outer shape of the positive electrode 5 (outer peripheral contour when viewed in a plan view along the stacking direction) is the outer shape of the negative electrode 3 (outer peripheral contour when viewed in a plane along the stacking direction). ) Slightly smaller. That is, the outer shapes of the electrode connection portion 5a and the electrode body 5b of the positive electrode 5 are slightly smaller than the outer shapes of the electrode connection portion 3a and the electrode body 3b of the negative electrode electrode 3.

As shown in FIG. 2, the positive electrode electrode 5 includes a band-shaped positive electrode current collector 30 and a positive electrode active material layer 32 formed on both sides of the positive electrode current collector 30. As shown in FIG. 4, an extending portion (positive electrode electrode terminal) 31 of the positive electrode current collector 30 is formed at one end of the positive electrode electrode 5. The positive electrode terminal 31 is a portion of the positive electrode current collector 30 extending outward from the electrode body 5b located at one side end in the longitudinal direction of the positive electrode 5.

For example, the positive electrode current collector 30 is made of a metal material such as aluminum, an aluminum alloy, or stainless steel. The positive electrode active material layer 32 contains a positive electrode active material, a conductive auxiliary agent, a binder, a thickener and the like. For example, the positive electrode active material layer 32 is formed of a composite metal oxide such as lithium cobalt oxide and lithium nickel oxide. For example, examples of the conductive auxiliary agent include carbon blacks, carbon materials, and fine metal powders. For example, examples of the binder include resin materials such as polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR) and polytetrafluoroethylene (PTFE). For example, examples of the thickener include resin materials such as carboxymethyl cellulose (CMC).

[Separator layer]
As shown in FIG. 4, the separator layer 6 has a strip shape in a zigzag folded state. Like the positive electrode 5 described above, the separator layer 6 includes four electrode connecting portions 6a and five overhanging portions 6b. The outer shapes of the electrode connecting portion 6a and the overhanging portion 6b in the separator layer 6 are substantially the same size as the electrode connecting portion 3a and the electrode body 3b in the negative electrode electrode 3.
The positive electrode electrode 5 is configured to include positive electrode active material layers 32 on both sides of the positive electrode current collector 30, and is composed of a plurality of electrode connecting portions 5a, an electrode body 5b, and an electrode terminal 31 in a plan view in a deployed state. The separator layer 6 covers almost the entire portion of the positive electrode electrode 5 except for the tip end portion of the electrode terminal 31. Of the five electrode bodies 5b arranged in a strip shape, most of the front and back surfaces of the electrode body 5b located at the end opposite to the side where the electrode terminal 31 is provided is covered with the separator layer 6. However, an arc-shaped unformed portion 5e in a plan view not covered by the separator layer 6 is formed on a part of the front and back surfaces (outer peripheral surfaces), and insulation made of insulating tape covering the unformed portions 5e on both the front and back surfaces. Layer 6f is provided. The width of the insulating layer 6f is formed to be slightly larger than that of the electrode terminal 31, and the insulating layer 6f covers the unformed portion 5e of the separator layer and is flat so as to slightly protrude outward from the arc-shaped outer peripheral contour of the electrode body 5b. It is formed in a rectangular shape.

The separator layer 6 is composed of a resin layer formed by applying a paint and curing the coating film.
As the coating material for forming the separator layer 6, for example, polyethylene oxide (PEO), polypropylene oxide (PPO), or a copolymer thereof and a lithium salt added as a supporting salt to the electrolytic solution are dissolved in a solvent such as acetonitrile. Paint can be used.
Alternatively, a solution obtained by dissolving polyvinylidene fluoride (PVDF) and a lithium salt added as a supporting salt to the electrolytic solution in a solvent such as N-methyl-2-pyrrolidone (NMP) may be used.
After applying these paints to form a coating film, the solvent is blown off by means such as heating, light irradiation, and drying to cure the coating film, whereby the separator layer 6 can be formed.
Further, in order to reinforce the strength of the separator layer 6, it is also effective to simultaneously dissolve an inorganic or organic powder in the paint.

[Exterior body]
With reference to FIGS. 1 and 2, the exterior body 10 includes a gasket 13 that electrically insulates the positive electrode can body 11, the negative electrode can body 12, and the positive electrode can body 11 and the negative electrode can body 12. ing.
The positive electrode can body 11 and the negative electrode can body 12 have a flat bottomed cylindrical shape. The inner diameter of the positive electrode can body 11 is slightly larger than the outer diameter of the negative electrode can body 12. The electrode laminated structure 2 is sandwiched between the bottom surface of the negative electrode can body 12 and the bottom surface of the positive electrode can body 11 in a state where the tubular portion of the negative electrode can body 12 is inserted into the positive electrode can body 11.

The gasket 13 is arranged between the outer peripheral surface of the tubular portion of the negative electrode can body 12 and the inner peripheral surface of the tubular portion of the positive electrode can body 11. The electrode laminated structure 2 is sealed in the exterior body 10 by the gasket 13. With reference to FIGS. 2 and 3, the positive electrode can body 11 is connected to the electrode terminal 31 of the positive electrode current collector 30 of the stacking unit 2A and functions as a positive electrode. On the other hand, the negative electrode can body 12 is connected to the electrode terminal 21 of the negative electrode current collector 20 of the stacking unit 2A, and functions as a negative electrode terminal. In FIG. 2, the electrode terminals 21 and 31 are not shown.

In this embodiment, the electrode laminated structure 2 is enclosed in the exterior body 10 to form a coin shape, but the present embodiment is not limited to this structure, and the electrode laminated structure 2 is not limited to this structure. May be adopted in a laminated pack made of a laminated film, and a lead wire electrically connected to the electrode laminated structure 2 is projected outward from the laminated pack.
A laminated pack made of a laminated film is superior in sealing performance to a can body structure composed of a positive electrode can body 11, a negative electrode can body 12, and a gasket 13, and thus has a feature of excellent long-term reliability as a battery.

"Electrode manufacturing method: first embodiment"
Next, an example of a method for manufacturing the positive electrode 5 having the above-mentioned unformed portion 5e and the separator layer 6 having a structure in which the insulating layer 6f is omitted will be described.
First, a coating liquid (slurry) containing a constituent material for forming the positive electrode active material layer 32 is prepared. Hereinafter, the coating liquid containing the constituent material for forming the positive electrode active material layer 32 is referred to as a “positive electrode slurry”. The positive electrode slurry contains the above-mentioned positive electrode active material, conductive auxiliary agent, binder, thickener and the like. The solvent of the slurry may be any solvent that dissolves the binder and the thickener and disperses the active material and the conductive auxiliary agent.

Next, FIG. 5 has a rectangular shape in a plan view in which the vertical width in a plan view is larger than the total length of the target positive electrode 5 in the deployed state shown in FIG. 4 and a plurality of positive electrodes 5 can be aligned in the horizontal width direction. The current collector sheet 50 shown is prepared.
Since the current collector sheet 50 becomes the positive electrode current collector 30 after processing, it is made of a metal sheet such as aluminum, an aluminum alloy, or stainless steel as described above. As an example, their thickness is about 10 μm.
Here, for the sake of simplification of the explanation, it is assumed that two positive electrode 5s are manufactured at the same time, and the width of the current collector sheet 50 is set to about 3 to 4 times the width of the positive electrode 5. explain. Since the number of positive electrode 5s formed on one current collector sheet 50 is not particularly limited, a current collector sheet having a wider width of the current collector sheet 50 shown in FIG. 5 can be used. In that case, more positive electrodes 5 can be produced by punching at the same time.

With respect to the vertically long rectangular current collector sheet 50 shown in FIG. 5, current is collected except for a strip-shaped (rectangular) region (uncoated portion) 50a having a predetermined width on the upper front and back surfaces of the current collector sheet 50. The above-mentioned positive electrode slurry is applied to the front and back surfaces of the body sheet 50, dried, and cured to form the positive electrode active material layer 51. The vertical width a of the uncoated portion 50a shown in FIG. 5 is formed to be slightly larger than the electrode terminal 31 of the positive electrode electrode 5 to be manufactured, and the vertical width b of the region coated with the positive electrode active material layer 51 is the electrode shown in FIG. It is formed slightly larger than the total length of the structure 4.

Next, as shown in FIG. 6, punching is performed to form two outline outlines of the positive electrode 5 having a size intended for plan view so as to be parallel to the left and right sides of the current collector sheet 50.
In the state shown in FIG. 6, the five electrode main bodies 5b are connected in a band shape by the four electrode connecting portions 5a, and the electrode terminal corresponding portion 31a protrudes from the end portion of the electrode main body 5b provided on the uncoated portion 50a side. The positive electrode active material layer 51 and the current collector sheet 50 are formed so as to be continuous with the uncoated portion 50a so that the extending portion 5c protrudes from the end portion of the electrode body 5b provided at the opposite end portion. Punched portions 52, 53, 54 are formed in the laminate.
By forming these punched portions 52 to 54, the electrode structure corresponding portion 48, the electrode terminal corresponding portion 31a, and the extending portion 5c corresponding to the outline outline of the two electrode structures 4 are formed inside the punched portions 52 to 54. A band-shaped structure 49 composed of the same is formed.
These two strip-shaped structures 49 are provided in a state of being supported at both ends inside the punched portions 52 to 54 by the electrode terminal corresponding portion 31a and the extending portion 5c.

Next, a printing method such as a screen printing method, a doctor blade method, a spray coating method, an inkjet coating method, a dipping method, or a die coating method is used on the front and back surfaces of the current collector sheet 50 after forming the punched portions 52 to 54. The paint for forming the separator layer is applied to form a coating film. The coating range of this coating film is the forming range of the active material layer 51. That is, a coating film for forming a separator layer is formed on the active material layer 51 of the portion of the current collector sheet 50 excluding the uncoated portion 50a and excluding the punched portions 52 to 54.

When a coating film is formed on the front and back surfaces of the current collector sheet 50 after the punched portions 52 to 54 are formed by the above-mentioned printing method, the coating film wraps around, so that the side surface (outer peripheral surface) of the electrode structure corresponding portion 48 is formed. ) Can be covered with a coating film. Further, the side surface on the base end side of the electrode terminal corresponding portion 31a and the side surface of the extending portion 5c can also be covered with the coating film.
Further, the current collector sheet 50 is a metal conductive sheet having a thickness of about 10 μm, and is not a strong sheet, but the electrode structure corresponding portion 48 is formed by the electrode terminal corresponding portion 31a and the extending portion 5c. Since both ends are supported, deformation of the electrode structure corresponding portion 48 can be suppressed during the above-mentioned printing.

For example, as compared with the cantilever support state of the strip-shaped structure 115 described above with reference to FIGS. 24 and 25, the electrode structure corresponding portion 48 can be supported in a more stable state by adopting the structure shown in FIG. .. In the cantilever support structure of the strip-shaped structure 115 as shown in FIG. 24, there is a high possibility that the electrode terminal 113f or the middle portion of the strip-shaped structure 115 is bent, but in the structure of FIG. , Bending is unlikely to occur in these corresponding parts.
Therefore, a well-shaped and undeformed electrode structure corresponding portion 48 can be obtained even after the coating film is formed.

After forming the coating film, according to the curing conditions of the resin constituting the coating film, for example, if it is a thermosetting resin, it is heated to a curing temperature, and if it is a photocurable resin, the strength and wavelength required for curing. The coating film is cured by a treatment such as irradiating with the light of the above, or by a treatment such as drying.
The electrode connecting portion 6a can be formed by curing the coating film covering the electrode connecting portion 5a, and the separator layer 6 can be formed by curing the coating film covering the electrode body 5b to form the overhanging portion 6b. .. Further, the coating film covering the extending portion 5c can be cured to form the coating film extending portion 6c.
From the state shown in FIG. 7, the tip portion of the electrode terminal corresponding portion 31a is cut from the current collector sheet 50, and at the base end portion on the electrode body side of the coating film extending portion 6c, the first embodiment shown in FIG. The positive electrode 5 in the form can be obtained.
The positive electrode 5 has a laminated structure having active material layers 32 on the front and back surfaces of the positive electrode current collector 30, and a strip-shaped positive electrode 5 in which five electrode bodies 5b are connected by four electrode connecting portions 5a in a plan view is separated. The structure is covered with the layer 6.

Since the positive electrode 5 is cut at the portion where the coating film extends 6c, a part of the side surface of the positive electrode current collector 30 is exposed at this cut portion, but the area of the exposed portion is small. Moreover, since the exposed portion is limited to the peripheral portion of the positive electrode 5 on one end side, the risk of short circuit occurrence is small even when the positive electrode 5 has a zigzag structure.

Further, by punching the current collector sheet 50 so as to form the two strip-shaped structures 49 in parallel, the two strip-shaped structures 49 can be formed by punching the current collector sheet 50 once.
By cutting out the two strip-shaped structures 49 from the current collector sheet 50 after this punching, two electrodes 5 can be obtained at the same time. Therefore, by using a current collector sheet having a larger area as the current collector sheet 50, it is possible to produce a larger number of electrodes from one current collector sheet, and mass production of electrodes becomes possible.

"Electrode manufacturing method: Electrode of the second embodiment"
Next, in the case of manufacturing the positive electrode 5, a method of manufacturing the electrode in which the exposure of the positive electrode current collector 30 to the side surface of the positive electrode is suppressed will be described below.
With respect to the vertically long rectangular current collector sheet 50 shown in FIG. 9, current is collected except for a strip-shaped (rectangular) region (uncoated portion) 50a having a predetermined width on the upper front and back surfaces of the current collector sheet 50. The above-mentioned positive electrode slurry is applied to the front and back surfaces of the body sheet 50, dried, and cured to form the active material layer 51.
The vertical width a of the uncoated portion 50a and the vertical width b of the active material layer 51 shown in FIG. 9 may be the same as those of the current collector sheet 50 used in the case shown in FIG.

Next, as shown in FIGS. 9 and 10, the end side of the front and back surfaces of the current collector sheet 50 on the side where the uncoated portion 50a is not provided is covered over a predetermined width (c). An insulating tape (insulating layer) 55 with an adhesive layer is attached.
In the embodiment shown in FIGS. 9 and 10, one end side of the current collector sheet 50 is covered with an insulating tape 55 by a predetermined width, and then the insulating tape 55 has a predetermined width outside the current collector sheet 50. Paste in. Then, in this protruding portion, the adhesive layer of the insulating tape 55 on the front surface side of the current collector sheet 50 and the adhesive layer of the insulating tape 55 on the back surface side of the current collector sheet 50 are overlapped with a constant width to form a layered portion of the insulating tape 55. Form 55a.

Next, as shown in FIG. 11, punching is performed to provide two outline outlines of the positive electrode 5 having a size intended for plan view so as to be arranged side by side on the current collector sheet 50. In the state of FIG. 11, the five electrode bodies 5b are connected in a band shape by the four electrode connecting portions 5a, and the electrode terminals 31 are not projected from the ends of the electrode bodies 5b provided on the uncoated portion 50a side. Punched portions 52, 53, 54 are formed on the current collector sheet 50 so as to be continuous with the coating portion 50a and have a shape in which the extending portion 5c protrudes from the end portion of the electrode body 5b provided at the opposite end portion. .. The formation positions and shapes of the punched portions 52, 53, and 54 may be similar to those of the embodiment described above based on FIG.

However, since the insulating tape 55 is attached in the state of FIG. 11, punching is performed so that the edge 55b of the portion where the insulating tape 55 covers the current collector sheet 50 slightly covers the outer peripheral portion of the nearest electrode body 5b. Parts 52, 53, 54 are formed.
By forming these punched portions 52 to 54, the electrode structure corresponding portion 48, the electrode terminal corresponding portion 31a, and the extending portion 55c corresponding to the outline outline of the two electrode structures 4 are formed inside the punched portions 52 to 54. A band-shaped structure 56 made of the material is formed. Further, the structure is such that a part of the outer peripheral portion of the electrode body 5b on the farthest side from the electrode terminal corresponding portion 31a and the extending portion 55c continuous therewith are covered with the punched extending portion 55c of the insulating tape 55.
Similar to the strip-shaped structure 49 having the structure shown in FIG. 6, these two strip-shaped structures 56 are formed inside the punched portions 52 to 54 by the electrode terminal corresponding portion 31a, the extending portion 5c, and the punching extending portion 55c. It is provided with both ends supported.

Next, a printing method such as a screen printing method, a doctor blade method, a spray coating method, an inkjet coating method, a dipping method, or a die coating method is used on the front and back surfaces of the current collector sheet 50 after forming the punched portions 52 to 54. A coating film for forming a separator layer is applied. The coating range of this coating film is the forming range of the active material layer 51 except for the portion where the insulating tape 55 is provided. That is, it is a portion of the current collector sheet 50 excluding the uncoated portion 50a and excluding the punched portions 52 to 54, and a separator layer is formed on the active material layer 51 excluding the region where the insulating tape 55 is provided. To form a coating film for When forming a coating film for forming a separator layer, it may be further laminated on the insulating tape 55.

When a coating film is formed on the front and back surfaces of the current collector sheet 50 after the punched portions 52 to 54 are formed by the above-mentioned printing method, the coating film wraps around, so that the side surface (outer peripheral surface) of the electrode structure corresponding portion 48 is formed. ) Can be covered with a coating film.
Further, the current collector sheet 50 is a metal conductive sheet having a thickness of about 10 μm, and is not a strong sheet, but an electrode terminal corresponding portion 31a, an extension portion 5c, and a punched extension portion of the insulating tape 55. Since the electrode structure 4 is supported at both ends by the 55c, deformation of the electrode structure corresponding portion 48 can be suppressed during the above-mentioned printing.
For example, as compared with the cantilever support state of the strip-shaped structure 115 described above with reference to FIGS. 28 and 29, the electrode structure corresponding portion 48 can be supported in a more stable state by adopting the structure shown in FIG. ..
In the cantilever support structure of the strip-shaped structure 115 as shown in FIG. 28, there was a high possibility that bending or the like would occur at the portion of the electrode terminal 113f or the middle portion of the strip-shaped structure 115, but in the structure of FIG. , Bending is unlikely to occur in these corresponding parts.
Therefore, a well-shaped and undeformed electrode structure corresponding portion 48 can be obtained even after the coating film is formed.

After forming the coating film, according to the curing conditions of the resin constituting the coating film, for example, if it is a thermosetting resin, it is heated to a curing temperature, and if it is a photocurable resin, the strength and wavelength required for curing. The coating film is cured by a treatment such as irradiating with the light of.
The electrode connecting portion 6a can be formed by curing the coating film covering the electrode connecting portion 5a, and the separator layer 6 can be formed by curing the coating film covering the electrode body 5b to form the overhanging portion 6b. ..

The second embodiment shown in FIG. 13 is obtained by cutting the tip portion of the electrode terminal corresponding portion 31a from the current collector sheet 50 from the state shown in FIG. 12 and cutting at the base end portion on the electrode body side of the punched extension portion 55c. Positive electrode 40 can be obtained.
The positive electrode 40 has a laminated structure having active material layers 32 on the front and back surfaces of the positive electrode current collector 30, and a strip-shaped positive electrode 5 in which five electrode bodies 5b are connected by four electrode connecting portions 5a in a plan view is separated. The structure is covered with the layer 6. Further, the positive electrode 40 has a structure in which the cut portion of the punched out extension portion 55c is covered with an insulating tape (insulating layer) 6f.
The positive electrode electrode 40 has a structure in which the active material layer 32 is provided on the positive electrode current collector 30 and the outer periphery thereof is covered with the separator layer 6, but the outer periphery of the electrode body 5b located at one end of the electrode structure 4 is formed. It is characterized by a structure in which a portion is partially covered with an insulating layer 6f made of an insulating tape. By providing the insulating layer 6f, the insulating property of the outer peripheral portion of the electrode body 5b located at one end of the electrode structure 4 can be further improved.

"Third embodiment"
In the case of manufacturing the positive electrode 40 of the second embodiment, the insulating layer 6f was formed by attaching the insulating tape 55 and then punching it, but the area to which the insulating tape 55 was attached was not coated with the active material layer 51. It may be formulated as an area.
The position where the active material layer 51 is applied is adjusted so that the position of the insulating tape 55 shown in FIGS. 11 and 12 is the uncoated portion of the active material layer. Specifically, when the active material layer 51 is applied to the front and back surfaces of the current collector sheet 50 and the insulating tape 55 is attached as shown in FIG. 9, the attachment of the insulating tape 55 is omitted, and the insulating tape 55 is attached. The area to be attached is defined as the uncoated portion and the area where the active material layer 51 is not applied.

After that, as in the case of FIG. 12, a paint for forming a separator layer is applied around the electrode structure corresponding portion 48 and the above-mentioned uncoated portion, dried, and the coating film is cured to form a separator layer. ..
By the above manufacturing method, the electrode 40A of the third embodiment shown in FIG. 14 can be manufactured. The electrode 40A has the same structure as the electrode 4 shown in FIG. 4, but the difference is that the insulating layer 6f is omitted, and the electrode body 5b on the side opposite to the side where the electrode 31 is provided has a part of the outer peripheral portion. The point is that the notch portion 5f is formed, and the covering portion 6g of the separator layer 6 is formed so as to cover the notch portion 5f.

In the production of the second embodiment, the insulating tape 55 is attached on the active material layer 51, but in the third embodiment, the portion to which the insulating tape 55 is stretched is previously uncoated portion of the active material layer 51. It is said. As a result, the separator layer 6 can be arranged instead of the insulating layer 51 on the portion where the insulating tape 55 is stretched, and the electrode 40A can be configured not to be thickened by the thickness of the insulating layer. Even if there is a gap between the uncoated part and the active material layer, if the paint is applied so as to cover the part and the separator layer 6 is formed, the part can be filled with the separator layer 6 and has a structure. The above problem does not occur.
By the way, the structure provided with the insulating layer 6f shown in FIGS. 4 and 13 described above is, for example, a structure particularly effective for the electrodes of the fourth embodiment described below.

"Electrode of the fourth embodiment and its manufacturing method"
FIG. 15 is a plan view showing a fourth embodiment of a positive electrode suitable for applying the present invention.
The positive electrode 60 of the fourth embodiment shown in FIG. 15 connects a plurality of (8 in the illustrated example) electrode bodies 63 arranged side by side in a row and a pair of adjacent electrode bodies 63 (at least one (8). (7 in the illustrated example) electrode connection portions 64 and electrode terminals 65 extending from the electrode body 63 on one end side are provided.
The positive electrode 60 shown in FIG. 15 has basically the same structure as the positive electrode 5 of the first embodiment shown in FIG. 4, except that the electrode body 63 has an oval shape in a plan view.
That is, the structure in which the active material layer is provided on one side or both sides of the current collector layer made of metal foil, and the paint is applied to almost the entire surface and covered with the separator layer 66 obtained by curing is the same. Further, in the positive electrode 5 located at the end opposite to the side where the positive electrode terminal 65 is provided, an unformed portion 60d in which a separator layer is not formed is provided on the outer peripheral edge thereof, and the electrode including this portion is provided. The structure in which the outer peripheral portion of the main body 63 is covered with a covering material 67f made of an insulating tape is also the same.

Hereinafter, a fourth embodiment according to the method for manufacturing the positive electrode 60 shown in FIG. 15 will be described with reference to FIG.
FIG. 16 is equivalent to the case where the positive electrode 5 of the second embodiment is manufactured, and two contour outlines of the positive electrode 5 are formed so as to be parallel to the left and right by punching as shown in FIG. Indicates the state of. That is, using the current collector sheet 66, the positive electrode slurry is applied except for the uncoated portion 66a, dried and cured to form a positive electrode active material layer, and an adhesive layer is formed on one end side of the current collector sheet 66. FIG. 16 shows a state in which two insulating tapes 67 with attachments are attached, and then punching is performed to form two outline outlines of the positive electrode 60 to be manufactured so as to be parallel to the left and right sides of the current collector sheet 66. Shown in. The same applies to the provision of the multilayer portion 67a on the insulating tape 67.

In the state of FIG. 16, eight electrode main bodies 63b are connected in a band shape by seven electrode connecting portions 63a, and the electrode terminal corresponding portion 63c is projected from the end portion of the electrode main body 63b provided on the uncoated portion 66a side. It is continuously connected to the uncoated portion 66a. Further, punched portions 68a, 68b, 68c are formed on the current collector sheet 66 and the insulating tape 67 so that the extending portion 63d protrudes from the end portion of the electrode body 63b provided at the opposite end portion. The formation positions and shapes of the punched portions 68a, 68b, and 68c may be similar to those of the embodiment described above with reference to FIG.
By forming the punched portions 68a, 68b, 68c, both ends of the electrode structure corresponding portion 69 to which the eight electrode main bodies 63b are connected are supported.

Next, as shown in FIG. 17, a coating film for forming a separator layer is applied, dried, and the coating film is cured in the same manner as in the second embodiment.
From the state shown in FIG. 17, the positive electrode 60 having the structure shown in FIG. 15 can be obtained by cutting the portion corresponding to the electrode terminal 63c and the extending portion 63d. When the extending portion 63d is cut, the positive electrode 60 shown in FIG. 15 can be obtained by cutting the portion where the insulating tapes 67 on the front and back surfaces overlap each other on the outside of the electrode body 63b.

A negative electrode 59 having a structure similar to that of the positive electrode 60 shown in FIG. 15 is separately formed by the same method, and a structure in which these are wound is shown in FIG. The negative electrode 59 is also provided with an electrode terminal 58 in the same manner as the electrode terminal 65 provided on the positive electrode 60, and when these are wound, the electrode terminal 65 on the positive electrode side is pulled out on one side and the other side is pulled out as shown in FIG. It is possible to obtain a wound electrode laminated structure 80 having a structure in which the electrode terminal 58 on the negative electrode side is pulled out.

In the electrode laminated structure 80 of the fourth embodiment shown in FIG. 18, since the electrode bodies provided on the positive electrode 60 and the negative electrode 59 are both oval-shaped, the insulating tape provided at the ends thereof is used. For example, the insulating tape 67f illustrated in FIG. 15 covers a wide range.
By providing the insulating tape 67f, even if the cut portion is long in the wound electrode laminated structure 80 shown in FIG. 18, the cut portion can be widely covered by the insulating tape 67f, so that the positive electrode end is provided. The insulation between the portion side and the end side of the negative electrode electrode can be improved.

FIG. 31 is a partial cross-sectional view showing an example configuration of a battery in which electrodes are housed in a laminate pack type container.
The battery 61 includes an electrode laminated structure 62 of electrodes, an electrolytic solution (electrolyte solution: not shown) impregnated in the electrode laminated structure 62, and an exterior body 70 containing the electrode laminated structure 62. There is. The electrode laminated structure 62 is composed of the electrode laminated structure of the negative electrode 3 and the positive electrode 5 described in the previous embodiment as an example.
The exterior body 70 has an accommodating portion 72 in which the electrode laminated structure 62 is accommodated, and a sealing portion 75 bent along the outer circumference 72a of the accommodating portion 72. The sealing portion 75 is bent upward along the outer circumference 72a of the accommodating portion 72 by drawing molding. The exterior body 70 includes a bottomed tubular first container 77 and a bottomed tubular second container 78. The first container 77 and the second container 78 are arranged so that their central axes are coaxial with each other.

In the first container 77, for example, a metal sheet made of Al or an Al alloy, a resin fusion layer forming the inner side surface of the first container 77, and a resin protective layer forming the outer surface are laminated. It consists of a laminated member.
The first container 77 includes a first bottom wall portion 81 and a tubular first peripheral wall portion 82. A round hole type first through hole 83 is formed in the central portion of the first bottom wall portion 81. The first through hole 83 is formed coaxially with the central axis O.
A negative electrode plate 85 is heat-sealed on the inner surface side of the first bottom wall portion 81 via a first sealant ring (insulating film) 84.
The inner surface of the negative electrode electrode plate 85 is connected to the negative electrode 3 of the electrode laminated structure 2. The negative electrode terminal 86 is welded to the outer surface of the negative electrode plate 85. The negative electrode terminal 86 penetrates the first through hole 83 and is exposed to the outside, and functions as a negative electrode terminal of the battery 1.

The second container 78 is made of the same laminated member as the first container 77. The second container 78 includes a disc-shaped second bottom wall portion 91, a tubular second peripheral wall portion 92, and a bent portion 93. The second peripheral wall portion 92 forms the outer circumference 72a of the accommodating portion 72.
A round hole-shaped second through hole 95 is formed in the center of the second bottom wall portion 91. A positive electrode plate 98 is heat-sealed on the inner surface of the second bottom wall portion 91 via a second sealant ring (insulating film) 97.
The inner surface of the positive electrode plate 98 is connected to the positive electrode 5. A positive electrode terminal 99 is fixed to the outer surface of the positive electrode plate 98. The positive electrode terminal 99 penetrates the second through hole 95 and is exposed to the outside, and functions as a positive electrode terminal of the battery 1.

The battery 61 can be configured by accommodating the electrode laminated structure 2 composed of the negative electrode electrode 3 and the positive electrode 5 or the positive electrode 40 of the embodiment described above together with the electrolytic solution in the laminate pack type container shown in FIG. 31.
If it is an electrode laminated structure 2 in which the negative electrode 3 and the positive electrode 5 of the above embodiment are folded and laminated, or an electrode laminated structure 57 formed by winding these electrodes, a current collector provided inside. Since the exposed portion of the layer is small or almost nonexistent, a structure with a low risk of internal short circuit can be provided.

By the way, in the embodiment described above based on FIGS. 6 and 11, the strip-shaped structures 49 and 56 are supported by both ends of the electrode terminal corresponding portion 31a and the extending portion 5c or the punched extending portion 55c. However, the positions where the extending portion 5c and the punched extending portion 55c are provided are not limited to the positions shown in FIGS. 6 and 11.
For example, in the plan view state shown in FIGS. 6 and 11, the positions where the extending portions 5c and 55c are provided are set below the outer peripheral portion of the electrode body 5b, but are located on the right side or on the outer peripheral portion of the electrode body 5b. It may be on the left side. The purpose can be achieved by forming the punched portions 52, 53, 54 and providing extending portions 5c, 55c so as to reach the remaining outer peripheral portion of the current collector sheet 50 to support the strip-shaped structures 49, 56 at both ends. Therefore, the forming positions of the extending portions 5c and 55c are not limited to the positions shown in FIGS. 6 and 11.

Further, in the embodiments described with reference to FIGS. 1 to 18, the electrode connection portion 5a is formed to be narrower than the electrode body 5b, but the width of the electrode connection portion 5a and the width of the electrode body 5b are the same. It doesn't matter if there is one. When these widths are the same, a simple tape-shaped electrode having a uniform width is zigzag or wound.
The present invention may be applied to an electrode having such a structure.

1 ... Battery, 2 ... Electrode laminated structure, 2A ... Overlapping unit, 3 ... Negative electrode electrode, 3a ... Electrode connection part, 3b ... Electrode body (overhanging part), 4 ... Electrode structure (positive electrode structure), 5 ... Positive electrode electrode, 5a ... Electrode connection part, 5b ... Electrode body (overhanging part), 5c ... Extended part, 5d ... Unformed part, 6 ... Separator layer, 6a ... Electrode connecting part, 6b ... Overhanging part, 6f ... Insulating tape (Insulation layer), 10 ... Exterior, 11 ... Positive electrode can body, 12 ... Negative electrode can body, 13 ... Gasket, 20 ... Negative electrode current collector, 21 ... Negative electrode terminal (extending part), 22 ... Negative electrode active material layer , 30 ... Positive electrode current collector, 31 ... Positive electrode terminal (extending part), 31a ... Electrode terminal equivalent, 32 ... Positive electrode active material layer, 40 ... Positive electrode, 48 ... Electrode structure equivalent, 49 ... Strip structure Body, 50 ... Current collector sheet, 51 ... Active material layer, 50a ... Uncoated part, 52, 53, 54 ... Punched part, 55 ... Insulating tape (insulating layer), 55c ... Punched extension part, 56 ... Strip structure Body, 62 ... Electrode laminated structure, 70 ... Exterior body.

Claims (9)

A plurality of electrode bodies are connected in a band shape via an electrode connection portion to form an electrode structure, and an electrode terminal is formed on an electrode body on one end side. The electrode structure is a current collector layer and both sides thereof. It is a method of manufacturing an electrode having a laminated structure having an active material layer and a separator layer formed in the above.
The active material layer is applied to the portion of the current collector sheet excluding the uncoated portion provided on both the front and back sides of the current collector sheet so that the coating range of the active material layer includes almost the entire outer peripheral contour of the electrode structure. A portion extending from the outer peripheral portion of the electrode body located on the other end side of the plurality of electrode bodies connected in a strip shape so that the uncoated portion of the active material layer includes the tip end portion of the electrode terminal. By forming a punched portion so that
A band-shaped structure composed of the electrode terminal corresponding portion, the electrode structure corresponding portion, and the extending portion is formed inside the punched portion in a state where both ends are supported by the electrode terminal corresponding portion and the extending portion.
Next, an insulating coating film for forming a separator layer is formed on the base end side of the electrode terminal corresponding portion, the electrode structure corresponding portion, and both the front and back surfaces of the extending portion, and the insulating coating film is cured to form the separator layer. A method for manufacturing an electrode, which comprises forming the electrode and then cutting it at the tip end side of the electrode terminal corresponding portion and the extending portion to obtain the electrode. The active material is adjacent to the end face of the current collector sheet and both sides of the end face, on the end side located opposite to the end side of the current collector sheet on which the uncoated portion of the active material layer is formed. After attaching the insulating layer that covers the edge of the material layer
The punched portion is formed in the sticking range of the insulating layer so as to form the extending portion and the outer peripheral portion of the electrode body following the extending portion, and then the insulation attached to the outer peripheral portion of the electrode body. The method for manufacturing an electrode according to claim 1, wherein the electrode is obtained by cutting the current collector sheet at a portion of the extending portion so as to leave a layer. The uncoated portion of the active material layer is partitioned on the end side located opposite to the end side of the current collector sheet on which the uncoated portion of the active material layer is formed.
When the punching is performed, a part of the electrode body following the extending portion and the extending portion is punched so as to be located at the uncoated portion, and both ends are supported by the electrode terminal corresponding portion and the extending portion. Form the electrode equivalent part
Next, when forming the insulating coating film for forming the separator layer, the insulating coating film is formed so as to include the uncoated portion, and then the insulating coating film is cured to form the separator layer. The method for manufacturing an electrode according to claim 1. As the current collector sheet, a current collector sheet having a length and width capable of arranging a plurality of the electrodes in parallel with each other is used, and the activity is on one side in the width direction orthogonal to the length direction of the current collector sheet. The uncoated portion of the material layer is formed in a band shape, and the tip end portion of the electrode terminal is positioned on the strip-shaped uncoated portion and punched so that the plurality of strip-shaped structures are lined up in the length direction of the current collector sheet. The method for manufacturing an electrode according to claim 1 or 2, wherein a portion is formed and the plurality of strip-shaped structures are separated from the current collector sheet to obtain a plurality of electrodes. When the insulating layer is provided on the end side of the current collector sheet, the insulating tape is attached from the outside of the front end side of the current collector sheet and the outside of the back surface end side of the current collector sheet. With the insulating tape, the end of the active material layer on the front end side of the current collector sheet, the end face of the current collector sheet, and the end of the active material layer on the back surface end side of the current collector sheet are attached with the insulating tape. The method for manufacturing an electrode according to any one of claims 2 to 4, wherein the electrode is covered. A plurality of electrode bodies are connected in a band shape via an electrode connection portion to form an electrode structure, and an electrode terminal is formed on the electrode body on one end side. The electrode structure is a current collector layer and its structure. An electrode having a laminated structure having an active material layer and a separator layer formed on both sides.
The outer peripheral surface of the electrode structure is covered with a separator layer made of a cured coating layer, and among the plurality of electrode bodies, the electrode body on the other end side with respect to the electrode body on one end side provided with the electrode terminal. An electrode characterized in that an unformed portion of the separator layer is formed on an active material layer on the outer peripheral portion of the front and back surfaces of the electrode body, and an insulating layer is coated around the unformed portion. The sixth aspect of claim 6, wherein the insulating layer is made of an insulating tape, and the end face of the outer peripheral portion of the electrode body on the other end side and the end portion of the active material layer sandwiching the end face are covered with the insulating tape. Electrodes. The pair of electrodes according to claim 6 or 7 is provided, the positive electrode is formed by using the active material of one electrode as the positive electrode active material, and the negative electrode is formed by using the active material of the other electrode as the negative electrode active material. At the same time, the positive electrode and the negative electrode were vertically folded by overlapping the electrode bodies on the side provided with the insulating layer, and the electrode main body of the positive electrode and the electrode body of the negative electrode were alternately laminated. An electrode laminated structure characterized by this. An electrochemical cell comprising the electrode laminated structure according to claim 8 inside an exterior body.

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