JP6482098B1 - Electrochemical cell and method for producing electrochemical cell - Google Patents

Abstract

An object of the present invention is to provide an electrochemical cell in which a positive electrode body is less misaligned. An electrochemical cell according to the present invention includes a plurality of positive electrode bodies arranged side by side, a strip-like positive electrode having an electrode connection portion connecting two adjacent positive electrode bodies, and a plurality of electrode bodies arranged side by side. A negative electrode main body, a strip-shaped negative electrode having an electrode connecting portion for connecting two adjacent negative electrode main bodies, and a separator disposed between the positive electrode and the negative electrode, the positive electrode main body and the negative electrode A superposition unit in which main bodies are alternately superposed via the separator is configured, and a plurality of superposition units are laminated and connected in parallel to each other. [Selection] Figure 1

Description

  The present invention relates to an electrochemical cell and a method for producing the electrochemical cell.

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

For example, a structure in which a strip-shaped electrode and a strip-shaped separator are wound and accommodated in a cylindrical or coin-shaped case, or a structure that is deformed into a flat shape and then accommodated in a laminate film is known.
In recent years, a configuration in which a belt-like electrode and a belt-like separator are folded in a folded manner has been studied in response to the demand for a thinner wearable device. For example, in the following Patent Document 1, a structure in which a strip-shaped electrode is accommodated in a separator bag is proposed.

JP-A-2005-243455

However, in the configuration in which the strip-shaped electrode is accommodated in the separator bag body, the electrode stacking position (facing position) may be deviated when winding, stacking, zigzag folding, or the like. In particular, when an electrode having a zigzag folded structure is employed, the belt-like electrodes are alternately folded while being accommodated in the separator bag, and therefore the possibility that the opposing surfaces of the electrodes are displaced is increased.
For example, when the number of stacks is small, the size of the face-to-face positional deviation is small, so it may be absorbed as a structural error range. There is a risk of disappearing.

In particular, when an electrochemical cell having a large number of stacked layers is formed in order to increase the capacity of the battery, there is a possibility that the misalignment of the facing surface for each stacked electrode cannot be ignored.
When laminating a plurality of zigzag folded electrodes, the next electrode is folded so as to circulate the next lower electrode. Therefore, wraparound error when wrapping, error of the folded part when zigzag folding, stacking positioning error, etc. are accumulated. As a result, the error of the facing position deviation for each electrode increases.
Therefore, in the conventional electrochemical cell, there was room for improvement in suppressing the shift of the electrode stacking position (facing position).

  The present invention has been made in view of the conventional situation as described above, and in the case where a stacked electrochemical cell is configured using a zigzag folded electrode, a structure capable of suppressing the face-to-face positional deviation for each stacked electrode. It is an object of the present invention to provide an electrochemical cell and a method for producing the electrochemical cell.

(1) In order to solve the above-described problem, an electrochemical cell according to an embodiment of the present invention has a strip-like shape having a plurality of positive electrode bodies arranged side by side and an electrode connection part that connects two adjacent positive electrode bodies. A positive electrode, a plurality of negative electrode bodies arranged side by side, a strip-shaped negative electrode having an electrode connecting portion for connecting two adjacent negative electrode bodies, and the positive electrode and the negative electrode are disposed between the positive electrode and the negative electrode The positive electrode body and the negative electrode body are alternately stacked in a folded manner via the separator, and the electrode connection portions are folded back to the outside of the positive electrode body and the outside of the negative electrode body, respectively. wherein alternate multilayer overlay unit of the negative electrode is constituted with, the superposition unit is stacked, while being connected in parallel with each other, the separator is arranged side by side A plurality of overhang portions and a connecting portion that connects two adjacent overhang portions, and the front and back surfaces of the plurality of positive electrode bodies of the positive electrode are covered by the overhang portions of the separator, and the electrodes of the positive electrode The front and back surfaces of the connecting portion are covered with the connecting portion of the separator to form a positive electrode structure, and the positive electrode structure and the negative electrode are alternately stacked to form the overlapping unit. And

  By laminating a plurality of overlapping units composed of positive electrodes and negative electrodes that are stacked in a zigzag manner, the amount of misalignment of the facing position of the positive electrode body that occurs in one overlapping unit is generated in the other overlapping units. It is possible to adopt a structure that does not affect the positional deviation amount of the facing position of the positive electrode body. If the amount of positional deviation in the individual overlapping units is reduced, the amount of positional deviation of the positive electrode body facing the whole laminated structure can be reduced.

In this regard, when all the positive electrode bodies to be stacked are connected and stacked in a folded manner, positional deviations are sequentially accumulated and increased from the start end side to the end side of the overlap structure. For this reason, there is a problem that the amount of positional deviation of the facing position of the positive electrode main body becomes large.
A plurality of superposition units composed of a positive electrode body and a negative electrode body, which are stacked in a zigzag form, are stacked, and the amount of displacement of the positive electrode body generated in each overlap unit is reduced, so that the positive electrode in the case of the entire laminated structure The facing position shift of the main body can be suppressed. By suppressing the facing position shift of the positive electrode main body, it is possible to prevent a decrease in capacity of the electrochemical cell. Moreover, a high capacity | capacitance electrochemical cell can be provided by connecting a some overlap unit in parallel.

(2) In the electrochemical cell according to the aspect, it is preferable that the outer peripheral contour of the positive electrode body is disposed inside the outer peripheral contour of the negative electrode body viewed along the overlapping direction in the one overlapping unit.

  In the structure of the electrochemical cell, it is desirable that the outer peripheral contour of the positive electrode body is disposed inside the outer peripheral contour of the negative electrode body. When the amount of protrusion of the outer peripheral contour of the positive electrode main body is large, there is a risk of precipitation of metal constituting ions applied to the electrochemical cell and a decrease in capacity.

(3) In the electrochemical cell according to one aspect, the lengths of the plurality of electrode connection portions in the positive electrode are the same, and the lengths of the plurality of electrode connection portions in the negative electrode are the same. The outer peripheral contour of the positive electrode body viewed along the overlapping direction in one overlapping unit is displaced for each overlapping layer, and the outer peripheral contour of the positive electrode body is the outer periphery of the negative electrode body in the layer having the largest positional displacement amount. It is preferable that it is arranged inside the contour.

  In the structure of the electrochemical cell, it is desirable that the outer peripheral contour of the positive electrode body is disposed inside the outer peripheral contour of the negative electrode body. When the amount of protrusion of the positive electrode main body is large, there is a risk of precipitation of metal constituting ions applied to the electrochemical cell and a decrease in capacity. These problems can be avoided by arranging the outer peripheral contour of the positive electrode main body inside the outer peripheral contour of the negative electrode main body even in the layer having the largest positional deviation amount in each superposition unit.

In one superposition unit, when the positive electrode body and the negative electrode body are alternately superposed, if the electrode connection portion and the electrode connection portion have the same length, the negative electrode body is caused by an overlay error or the like in accordance with an increase in the number of layers of superposition. The position where the positive electrode main body is superimposed on is gradually shifted.
Since the number of positive electrode bodies necessary for the entire electrochemical cell is divided into a plurality of overlapping units instead of one overlapping unit and individually folded, the number of folding required for one overlapping unit can be reduced. Accordingly, the amount of misalignment of the facing of the positive electrode main body in one overlapping unit can be reduced.

(4) In the electrochemical cell of the one aspect, the belt-like positive electrode and the belt-like negative electrode are viewed along the overlapping direction of the positive electrode main body and the negative electrode main body from the start end side to the terminal end side of the overlap. A configuration in which the amount of positional deviation of each outer peripheral contour is increased can be employed.

  When the belt-like positive electrode and the belt-like negative electrode are overlapped while being folded, if the lengths of the electrode connecting portions are the same, the amount of displacement of the positive electrode body is accumulated and increased each time the number of overlaps increases. . Even with this structure, if the amount of positional deviation of the positive electrode body is suppressed in units of a plurality of overlapping units, the accumulation of the amount of positional deviation of the positive electrode body can be reduced, and the amount of positional deviation of the positive electrode body is suppressed. An electrochemical cell can be provided.

(5) In the electrochemical cell of the one aspect, in the stacked adjacent overlapping units, a positive electrode side connection electrode terminal is derived from the closest positive electrodes of one overlapping unit and the other overlapping unit, These positive electrode side connection electrode terminals are connected to each other, the negative electrode side connection electrode terminals are derived from the closest negative electrode electrodes of one overlapping unit and the other overlapping unit, and these negative electrode side connection electrode terminals are connected to each other. Can be adopted.

  If the adjacent positive electrode side connection electrode terminals of adjacent overlapping units are connected to each other and the closest negative electrode side connection electrode terminals are connected to each other, the side surface of the laminate is compared with the case where the connection electrode terminals are derived from other positions. The amount of connection electrode terminal wraparound to the side can be reduced. For this reason, a connection electrode terminal can be derived | led-out to the outer side of a laminated body in the state with little wraparound amount.

(6) In the electrochemical cell according to the one aspect, in at least one of the positive electrode and the negative electrode, the length of the connecting portion on the end side of the overlapping is longer than the length of the connecting portion on the starting end side of the overlapping Can be adopted.

  If the length of the connection portion on the end side of the overlap is made longer than the length of the connection portion on the start end side of the overlap, a long connection portion is used even if the overall thickness of the electrode gradually increases due to the overlap. It can laminate | stack so that the shift | offset | difference of the facing position of a positive electrode main body or a negative electrode main body may be eliminated.

(7) The method for producing an electrochemical cell according to one aspect of the present invention includes a plurality of positive electrode bodies arranged side by side and a belt-like positive electrode having electrode connection portions that connect two adjacent positive electrode bodies. A plurality of negative electrode bodies arranged in a strip and a strip-shaped negative electrode having an electrode connecting portion for connecting two adjacent negative electrode bodies, with a separator interposed between the positive electrode body and the negative electrode body, outside the positive electrode body The electrode connection portions are folded individually on the outside of the negative electrode body, and alternately stacked in a zigzag manner to form an alternately stacked type overlapping unit of the positive electrode and the negative electrode, and a plurality of the overlapping units are stacked. , when connected in parallel to each other, the separator is a strip having a connection portion connecting the two said projecting portions adjacent the plurality of overhang and disposed side by side And covering the front and back surfaces of the plurality of positive electrode bodies of the positive electrode with the protruding portion of the separator, and covering the front and back surfaces of the electrode connecting portion of the positive electrode with the connecting portion of the separator, and constituting the positive electrode structure, The superposition unit is configured by alternately stacking positive electrode structures and the negative electrodes .

  By laminating a plurality of overlapping units composed of positive electrodes and negative electrodes that are superimposed in a zigzag manner, the amount of displacement of the positive electrode body or negative electrode body that occurs in one overlapping unit is generated in another overlapping unit. It is possible to manufacture an electrochemical cell having a structure that does not affect the amount of displacement of the positive electrode body or the negative electrode body. If the amount of positional deviation of the individual overlapping units is reduced, the amount of positional deviation of the positive electrode main body as the entire laminated structure can be reduced.

In this regard, when the structure is such that all the positive electrode bodies to be stacked are connected and overlapped, the positional deviation is sequentially accumulated and increased from the start end side to the end side of the overlap structure. For this reason, there is a problem that the amount of positional deviation of the positive electrode main body becomes large.
The position of the entire laminated structure can be reduced by reducing the amount of misalignment that occurs in each overlapping unit by using an electrochemical cell that stacks multiple overlapping units composed of positive and negative electrode bodies stacked in a zigzag manner. The amount of deviation can be suppressed.

(8) In the method for manufacturing an electrochemical cell according to the one aspect, the superposition is performed so that the outer peripheral contour of the positive electrode main body is placed inside the outer peripheral contour of the negative electrode main body viewed along the overlapping direction in the one overlapping unit. It is preferable to match.

  In the structure of the electrochemical cell, it is desirable that the outer peripheral contour of the positive electrode main body is disposed inside the outer peripheral contour of the negative electrode main body. When the amount of protrusion of the positive electrode main body is large, the metal constituting the ions applied to the electrochemical cell There is a risk of precipitation and a decrease in capacity. In the above manufacturing method, there is no risk of precipitation of the metal constituting the ions for the electrochemical cell by overlapping the outer peripheral contour of the positive electrode main body so that the outer peripheral contour of the positive electrode main body enters, and there is a risk of capacity reduction. Can provide no electrochemical cell.

(9) In the method of manufacturing an electrochemical cell according to one aspect, the positive electrode having the same length of the plurality of electrode connection portions and the negative electrode having the same length of the plurality of electrode connection portions are used. The outer peripheral contour of the positive electrode body in the layer with the largest amount of displacement is the negative electrode body so that the outer peripheral contour of the positive electrode body viewed along the overlapping direction in one overlapping unit is displaced for each overlapping layer. It is preferable to superimpose so that it may enter inside the outer periphery outline.

  In the structure of the electrochemical cell, it is desirable that the outer peripheral contour of the positive electrode main body is disposed inside the outer peripheral contour of the negative electrode main body. When the amount of protrusion of the positive electrode main body is large, the metal constituting the ions applied to the electrochemical cell There is a risk of precipitation and a decrease in capacity. Even if it is the layer with the largest amount of misalignment in each superposition unit, the outer peripheral contour of the positive electrode main body is arranged inside the outer peripheral contour of the negative electrode main body, which can eliminate the risk of electrolyte component deposition and may reduce the capacity. Does not occur.

(10) In the method for manufacturing an electrochemical cell according to the aspect, the positive electrode main body and the negative electrode main body are aligned in the overlapping direction of the belt-shaped positive electrode and the belt-shaped negative electrode from the start end side to the terminal end side of the overlap. It is also possible to have a structure in which the positions of the individual outer peripheral contours viewed are overlapped so as to increase.

  When the belt-like positive electrode and the belt-like negative electrode are overlapped while zigzag, the length of the electrode connection portions is the same and the length of the electrode connection portions is the same. In addition, the amount of displacement of the positive electrode main body is accumulated and increased. Even with this structure, if a plurality of overlapping units are connected in parallel and the amount of positional deviation is suppressed in units of overlapping units, the cumulative amount of positional deviation of the positive electrode body can be reduced, and as a result An electrochemical cell in which the amount of deviation is suppressed can be provided.

(11) In the method of manufacturing an electrochemical cell according to one aspect, when stacking the superposition units, a positive electrode side connection electrode terminal is derived from the closest positive electrodes of one superposition unit and the other superposition unit. The positive electrode side connection electrode terminals are connected to each other, and the negative electrode side connection electrode terminals are derived from the closest negative electrode electrodes of the one overlapping unit and the other overlapping unit, and the negative electrode side connection electrode terminals are connected to each other. A connection configuration can be adopted.

  If the adjacent positive electrode side connection electrode terminals and adjacent negative electrode side connection electrode terminals of adjacent overlapping units are connected to each other, compared to the case where the connection electrode terminals are derived from other positions, the electrochemical cell It is possible to manufacture an electrochemical cell having a structure in which the connection electrode terminal can be led out to the outside of the electrochemical cell while reducing the amount of the connection electrode terminal that wraps around the side surface.

  By laminating a plurality of overlapping units composed of positive electrodes and negative electrodes stacked in a zigzag manner according to the present invention, the positional deviation amount of the positive electrode body generated in one overlapping unit is generated in another overlapping unit. It is possible to provide an electrochemical cell having a structure that does not affect the positional deviation amount of the positive electrode body. If the amount of positional deviation of the individual overlapping units is reduced, the amount of positional deviation of the positive electrode body relative to the negative electrode body can be reduced as a whole electrochemical cell.

It is a top view of the battery concerning a 1st embodiment. It is sectional drawing which follows the II-II line | wire of FIG. The 1st superposition unit built in the battery concerning a 1st embodiment is shown, (A) is a perspective view and (B) is a top view. It is a perspective view which shows an example of the positive electrode structure incorporated in the battery which concerns on 1st Embodiment. The 2nd superposition unit built in the battery concerning a 1st embodiment is shown, (A) is a perspective view and (B) is a top view. It is an expanded view of the positive electrode structure incorporated in the battery which concerns on 1st Embodiment. It is process drawing which shows an example of the process of manufacturing the positive electrode structure incorporated in the battery which concerns on 1st Embodiment. FIG. 7 is a process drawing following FIG. 6 in a process for manufacturing the positive electrode structure. 1A and 1B are development views of a superposition unit incorporated in a battery according to the first embodiment, in which FIG. 1A is a development view of a first superposition unit, and FIG. 2B is a development view of a second superposition unit. It is. It is a simplified top view for demonstrating the state which laminates | stacks the 1st superposition unit and the 2nd superposition unit incorporated in the battery which concerns on 1st Embodiment. 2 is a schematic diagram showing an example of arrangement of connection electrode terminals in the internal structure of the battery. It is a flowchart which shows an example of the method of manufacturing the battery which concerns on 1st Embodiment.

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

<First Embodiment>
[battery]
As shown in FIG. 1, the battery 1 of the present embodiment has a circular shape in plan view. Referring also to FIG. 2, the battery 1 includes a laminated body 2 including a first overlapping unit 2A and a second overlapping unit 2B, an electrolyte solution (not shown) impregnated in the laminated body 2, and a laminated body. And an exterior body 10 that accommodates 2.

[Laminate]
As shown in FIG. 3A, the first overlapping unit 2A has a negative electrode 3 folded in a zigzag shape and a zigzag shape in a direction intersecting with the negative electrode 3 so as to be alternately stacked with the negative electrode 3 The positive electrode structure 4 is provided. The outline of the structure of only the positive electrode structure 4 is shown in FIG.
Further, the second overlapping unit 2B is also folded in a direction intersecting with the negative electrode 3 so as to be alternately stacked with the negative electrode 3 folded in a zigzag shape as shown in FIG. The positive electrode structure 4 folded into a shape is provided. Then, the first overlapping unit 2A and the second overlapping unit 2B are stacked and connected in parallel to form the stacked body 2 shown in FIG.

The first overlapping unit 2A shown in FIG. 3A is drawn with the vertical relationship reversed with respect to the first overlapping unit 2A shown in FIG. Further, the second overlapping unit 2B shown in FIG. 5A is drawn in the same direction as the second overlapping unit 2B shown in FIG. That is, FIG. 5 for the second overlay unit 2 B of (A), the extended portion for explaining the first overlay unit 2A shown in FIG. 3 (A) is upside down, after the (negative electrode terminal) The overlapping units 2A and 2B are connected in parallel by connecting 21 and the extending portion (positive electrode terminal) 31 individually. These parallel connection structures will be described again later using FIG.

[Negative electrode]
The negative electrode 3 has a strip shape. The negative electrode 3 includes a plurality of electrode connection portions 3a and a plurality of overhang portions (negative electrode main bodies) 3b, similarly to the positive electrode 5 described later.

  As shown in FIG. 2, the negative electrode 3 includes a negative electrode current collector 20 and a negative electrode active material layer 22 formed on both surfaces of the negative electrode current collector 20. As will be described later, the negative electrode current collector 20 has a strip shape. As shown in FIG. 3A, an extension portion (negative electrode terminal) 21 of the negative electrode current collector 20 is formed at one end portion of the negative electrode 3. The negative electrode terminal 21 is a portion of the negative electrode current collector 20 that extends outward from the negative electrode body 3 b in the longitudinal direction of the negative electrode 3.

  For example, the negative electrode current collector 20 is formed of a metal material such as copper, nickel, and stainless steel. The negative electrode active material layer 22 includes a negative electrode active material, a conductive additive, a binder, a thickener, and the like. For example, the negative electrode active material layer 22 is formed of a carbon material such as graphite. For example, examples of the conductive assistant include carbon blacks, carbon materials, and metal fine powders. Examples of the binder include resin materials such as polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), and polytetrafluoroethylene (PTFE). For example, as a thickener, resin materials, such as carboxymethylcellulose (CMC), are mentioned.

[Positive electrode structure]
As shown in FIG. 4, the positive electrode structure 4 includes a positive electrode 5 and a separator 6 that covers the positive electrode 5. The positive electrode structure 4 is obtained by integrating a positive electrode 5 and a separator 6. The outer shape of the positive electrode structure 4 is substantially the same as the outer shape of the negative electrode 3.

[Positive electrode]
The positive electrode 5 has a strip shape. Specifically, the positive electrode 5 includes a plurality of electrode connection portions 5a and a plurality of positive electrode bodies 5b. Hereinafter, the direction orthogonal to the longitudinal direction of the positive electrode 5 is referred to as the “width direction of the positive electrode 5”. The electrode connecting portion 5 a is recessed to the inner side in the width direction of the positive electrode 5.
As shown in FIG. 6, in a state where the positive electrode 5 is expanded, the positive electrode main body 5 b is disposed at a position adjacent to the electrode connection portion 5 a in the longitudinal direction of the positive electrode 5. The positive electrode main body 5b protrudes in an arc shape outside the electrode connection portion 5a in the width direction of the positive electrode 5. In this embodiment, the positive electrode main body 5b has a disk shape and is connected in a straight line via the electrode connection portion 5a.

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

  3 to 5, the outer shape of the positive electrode 5 (outer contour when viewed in plan along the stacking direction) is the outer contour of the negative electrode 3 (outer contour when viewed in plan along the stacking direction). ) Is slightly smaller. That is, the outer shapes of the electrode connection portion 5 a and the positive electrode main body 5 b in the positive electrode 5 are slightly smaller than the outer shapes of the electrode connection portion 3 a and the negative electrode main body 3 b in the negative electrode 3.

  As shown in FIG. 2, the positive electrode 5 includes a strip-shaped positive electrode current collector 30 and a positive electrode active material layer 32 formed on both surfaces of the positive electrode current collector 30. As shown in FIG. 4 or 6, an extension part (positive electrode terminal) 31 of the positive electrode current collector 30 is formed at one end part of the positive electrode 5. The positive electrode terminal 31 is a portion of the positive electrode current collector 30 that extends outward from the positive electrode body 5 b in the longitudinal direction of the positive electrode 5.

  For example, the positive electrode current collector 30 is formed of a metal material such as aluminum and stainless steel. The positive electrode active material layer 32 includes a positive electrode active material, a conductive additive, 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 cobaltate or lithium nickelate. For example, examples of the conductive assistant include carbon blacks, carbon materials, and metal fine powders. Examples of the binder include resin materials such as polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), and polytetrafluoroethylene (PTFE). For example, as a thickener, resin materials, such as carboxymethylcellulose (CMC), are mentioned.

[Separator]
As shown in FIG. 4 or FIG. 6, the separator 6 has a strip shape in the developed state. Like the positive electrode 5 described above, the separator 6 includes a plurality of electrode connection portions 6a and six overhang portions 6b. The outer shapes of the electrode connection portion 6a and the overhang portion 6b in the separator 6 are substantially the same size as the electrode connection portion 3a and the negative electrode body 3b in the negative electrode 3.

  The separator 6 is a thin film having a pore structure having lithium ion conductivity. For example, the separator 6 is formed of a polyolefin material such as polypropylene (PP) and polyethylene (PE) and a resin material such as polytetrafluoroethylene (PTFE). The separator 6 is formed by integrating a pair of first separator 41 and second separator 42 shown in FIG. 7 by heat fusion. In FIG. 4, the first separator 41 and the second separator in a state where the pair of the first separator 41 and the second separator 42 shown in FIG. 42 is shown.

[Overlay unit]
The superposition unit 2A of the present embodiment is formed by bending the positive electrode structure 4 including the separator 6 having the configuration shown in FIG. 6 and the negative electrode 3 having a similar external shape to the separator 6 in a plan view so as to alternately overlap each other. It is configured by stacking. When the overlapping unit 2A is viewed in plan along the stacking direction as shown in FIG. 3B, the circular outer peripheral contour of the positive electrode body 5b is arranged inside the circular outer peripheral contour of the overhanging portion 6b of the separator 6. Has been.

  The overlapping unit 2B of the present embodiment is configured by bending the negative electrode 3 and the positive electrode structure 4 so as to alternately overlap each other. When the superposition unit 2B is viewed in plan along the stacking direction as shown in FIG. 5B, the circular shape of the positive electrode body 5b of the positive electrode 5 is inside the circular outer peripheral contour of the negative electrode body 3b of the negative electrode 3. The outer peripheral contour is arranged. This arrangement relationship is the same in all the positive electrode bodies 5b of the superposition unit 2B.

Note that the superposition unit 2A shown in FIG. 3A and the superposition unit 2B shown in FIG. 5A are drawn as models of ideally folded structures. However, when the zigzag folded structure is actually manufactured at the production site, if the lengths of the electrode connecting portions 3a and 5a are uniform, the thickness of the positive electrode main body 5b and the negative electrode main body 3b arranged in the lower layer when zigzag folding is performed. As a result, the total thickness of the stacked electrodes gradually increases. For this reason, there is a problem that it is not easy to accurately align the centers of the positive electrode bodies 5 b of all the positive electrodes 5 with the centers of the negative electrode bodies 3 b of all the negative electrodes 3.
For this reason, although not shown in the figure, in the overlapping unit 2A and the overlapping unit 2B, the positive electrode body 5b is strictly misaligned for each layer folded and overlapped.

However, in the superposition unit 2A of the present embodiment, when viewed in plan along the superposition direction, even if the circular outer peripheral contours of all the positive electrode main bodies 5b have some positional deviation, the negative electrode main body It is arranged inside the circular outer contour of 3b. Further, in the superposition unit 2B, when viewed in plan along the superposition direction, the negative electrode main body of the negative electrode 3 even if the circular outer peripheral contours of all the positive electrode main bodies 5b have some misalignment. It is arranged inside the circular outer contour of 3b.
The reason why the misalignment can be reduced in the overlapping units 2A and 2B is that the number of stacked positive electrode bodies of the overlapping units 2A and 2B is about six. The reason for this will be described in detail later.

[Exterior body]
1 and 2 together, the outer package 10 includes a positive electrode can body 11, a negative electrode can body 12, and a gasket 13 that electrically insulates the positive electrode can body 11 and the negative electrode can body 12 from each other. 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 laminated body 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 with the cylindrical portion of the negative electrode can body 12 being inserted into the positive electrode can body 11.

  The gasket 13 is disposed between the outer peripheral surface of the cylindrical portion of the negative electrode can body 12 and the inner peripheral surface of the cylindrical portion of the positive electrode can body 11. The laminate 2 is sealed to the exterior body 10 by the gasket 13. Referring to FIGS. 2, 3 and 5 together, the positive electrode can body 11 is connected to the extending portion 31 of the positive electrode current collector 30 of the superposition unit 2A and functions as a positive electrode. On the other hand, the negative electrode can body 12 is connected to the extending portion 21 of the negative electrode current collector 20 of the overlapping unit 2B, and functions as a negative electrode terminal. In FIG. 2, the electrode terminals 21 and 31 are not shown.

In the battery 1 of the present embodiment, the stacked body 2 has a parallel connection structure of the first overlapping unit 2A and the second overlapping unit 2B. The laminated body 2 is composed of the overlapping units 2A and 2B and has the following characteristics.
In the structure of the present embodiment, as an example, the superposition unit 2A has a superposition structure of six positive electrode bodies 5b and six negative electrode bodies 3b. It has a 12-layer structure. The overlapping unit 2B has a similar stacked structure.

  In the case of such a structure having a large number of stacks, assuming that the electrode connecting portions 3a and 5a have the same length, assuming that one stack unit is used instead of two stack units, the positive electrode main body is required for each stack. The position of the center of 5b is slightly shifted from the center position of the negative electrode body 3b. This is because the laminated body gradually thickens due to the stacking of the negative electrode body 3b and the positive electrode body 5b stacked when zigzag folding, the influence of the folding accuracy when zigzag folding, the influence of misalignment of the positive electrode body 5b, etc. It consists of multiple factors.

  When the battery 1 is configured, the positive electrode body 5b and the negative electrode body 3b are formed as large as possible in order to ensure capacity, and the electrode connection portions 3a and 5a are formed as short as possible. The face-to-face position shift increases due to the fact that the design is made to minimize the amount of protrusion of the portions 3a and 5a to the outside. 3 to 5, the bent portions of the electrode connecting portions 3a and 5a are drawn in a shape having a margin, but in the actual configuration, the bent portions of the electrode connecting portions 3a and 5a are more stretched than those drawings. The bent part has a small curvature and a small radius of curvature.

  Accordingly, when the number of stacks of the positive electrode body 5b and the negative electrode body 3b is about 6 to 12 layers and the number of stacks is small, the amount of misalignment is small, but when the number of stacks is larger than these, the amount of misalignment cannot be ignored. Depending on the number of stacked layers, the outer peripheral contour of the positive electrode body 5b may protrude from the outer peripheral contour of the negative electrode body 3b. When the outer peripheral contour of the positive electrode main body 5b protrudes from the outer peripheral contour of the negative electrode main body 3b in plan view, if the amount of protrusion is large, there is a risk of metallic lithium deposition in the lithium ion battery.

  In this respect, when the stacked body 2 is constituted by the two overlapping units 2A and 2B as described above, in each of the overlapping units, the maximum value of the positional deviation amount of the positive electrode main body 5b is set to one overlap. It becomes possible to make smaller than the case where the whole laminated body is comprised with a unit. Therefore, by adopting the structure of the present embodiment, it is possible to provide the battery 1 in which the positive electrode main body 5b has little misalignment with the facing surface.

  That is, in the structure of this embodiment, the positional deviation amount of the facing position of the positive electrode body 5b generated in one superposition unit 2A is the positional deviation amount of the facing position of the positive electrode body 5b generated in the other superposition unit 2B. The structure does not affect the. Therefore, if the amount of misalignment between the individual overlapping units 2A and 2B is reduced, the amount of misalignment of the positive electrode body 5b as a whole can be reduced.

Further, when the laminated body is composed of one superposition unit and all the positive electrode bodies to be laminated are connected and superposed, the positional deviation is accumulated sequentially from the start side to the end side of the superposition structure. Become. For this reason, there is a problem that the amount of positional deviation of the facing position of the positive electrode main body becomes large. In this embodiment, this problem can be solved.
In the battery 1 of this embodiment, since the overlapping units 2A and 2B are connected in parallel in the stacked body 2, the overlapping unit has an effect that the capacity can be doubled as compared with one battery.

By the way, in the structure of the first embodiment, six positive electrode bodies 5b and six negative electrode bodies 3b are provided, and the present invention is applied to an electrochemical cell having a 12-layer structure with only the electrode body. However, the present invention is applied. The number of stacked electrode bodies is not particularly limited, and any number of layers can be applied.
Moreover, in the structure of 1st Embodiment, although the laminated body 2 was divided | segmented into two superposition units, the number of differentiation may be arbitrary. For example, the laminate 2 may be configured from three, four, or more overlapping units.

FIG. 11 is a configuration diagram illustrating an example of a state in which the positive electrode terminal 31 and the negative electrode terminal 21 are extended and wired when the laminate 2 is configured by two overlapping units 2A and 2B.
For example, after the positive electrode terminal 31 drawn out from the superposition unit 2A and the positive electrode terminal 31 drawn out from the superposition unit 2B are superposed, the positive electrode terminal 31 drawn out from the superposition unit 2A is extended to extend the extension 31a. And the extended portion 31a can be disposed on the bottom surface side of the stacked body 2.
Further, the negative electrode terminal 21 drawn from the superposition unit 2A and the negative electrode terminal 21 drawn from the superposition unit 2B are overlapped, and then the negative electrode terminal 21 drawn from the superposition unit 2B is extended to extend the extension 21a. And the extension 31a can be disposed on the upper surface side of the stacked body 2.

When the wiring structure shown in FIG. 11 is employed, the positive electrode terminal 31 and the negative electrode terminal 21 can be connected to the positive electrode can body 11 or the negative electrode can body 12 by going around about half the thickness of the laminate 2. With this wiring structure, it is possible to use a wiring in which no electrode terminals are arranged so as to extend over the entire height of the side surface of the laminate 2, and wiring with a uniform length can be formed on the positive electrode side and the negative electrode side.
Further, as shown in FIG. 11, if one of the positive electrode terminal 31 and the negative electrode terminal 21 drawn out from the overlapping units 2A and 2B is shortened to reduce the overlapping portion, the outer side of the laminated body 2 is removed. The protruding amount of the terminal portion with respect to the direction can be reduced.
Further, by shortening one of the positive electrode terminal 31 and the negative electrode terminal 21, there is an effect that the thickness of two terminals can be reduced as compared with a structure in which both are made longer. For this reason, if it has the effect which can make the structure of a battery thin, or if it is set as a battery with the same thickness, there exists an effect which can increase the quantity of an electrode.

  By the way, about the negative electrode main body 3b and the positive electrode main body 5b of the battery 1 demonstrated so far, all demonstrated the electrode structure arrange | positioned linearly via the electrode connection part 3a, 5a. However, the negative electrode 3 and the positive electrode 5 do not have to be linear, and even if they are connected in a shape such as a bent shape or a curved shape, the positive electrode or the negative electrode can be folded in a zigzag manner. The shape of is not questioned.

Moreover, in embodiment described so far, the structure which made all the length of electrode connection part 3a, 5a demonstrated was demonstrated. However, the lengths of the electrode connecting portions 3a and 5a are not necessarily constant and may be different. For example, in the case of the zigzag folding structure, a configuration in which the lengths of the electrode connecting portions 3a and 5a are longer on the terminal end side than the folding start end side may be adopted. In the case of the zigzag folding structure, a configuration in which the lengths of the electrode connecting portions 3a and 5a are gradually increased from the folding start end side to the termination end side may be adopted.
By adopting these structures, it is possible to always arrange the positive electrode body 5b at the same position even if the thickness of the stacked body increases according to the number of stacked layers. For this reason, even when a large number of batteries 1 are manufactured at the time of mass production or the like, the above-described structure may be employed when the length of the electrode connecting portions 3a and 5a can be managed.

Furthermore, in the said embodiment, although the laminated body 2 was enclosed in the exterior body 10 and the example which was made into the coin type | mold was demonstrated, this invention is not limited to this structure, The laminated body 2 is made from a laminate film. A structure in which a lead wire sealed in a laminate pack and electrically connected to the laminate 2 protrudes from the laminate pack may be employed.
In the case of a laminate pack made of a laminate film, since it has better sealing properties than the can structure composed of the positive electrode can body 11, the negative electrode can body 12, and the gasket 13, it has a feature of excellent long-term reliability as a battery.

[Battery manufacturing method]
Next, an example of the manufacturing method of the battery 1 described above will be described.
As shown in FIG. 12, the manufacturing method of the battery 1 includes an electrode processing step S1 for processing the positive electrode 5 into a predetermined shape, an electrode covering step S2 for covering the positive electrode 5 with a separator 6, and a coated positive electrode 5 separately. An electrode combination step S3 combined with the negative electrode 3 processed into a predetermined shape, and a zigzag folding step S4 in which the positive electrode structure 4 and the negative electrode 3 are alternately stacked in a state of being sandwiched via the separator 6 and folded into a zigzag shape.

  In this embodiment, since the overlapping units 2A and 2B are created, the S11 step (electrode processing step), the S12 step (electrode covering step), the S13 step (electrode combination step), which are equivalent to the steps S1 to S4, The S14 step (electrode combination step) is performed, and the overlapping units 2A and 2B are created by these steps. Hereinafter, steps S1 to S4 will be mainly described.

  First (that is, before the electrode processing step S1), a coating liquid (slurry) containing constituent materials for forming the positive electrode active material layer 32 and the negative electrode active material layer 22 is adjusted. Hereinafter, the coating liquid containing the constituent material for forming the positive electrode active material layer 32 is referred to as “positive electrode slurry”, and the coating liquid containing the constituent material for forming the negative electrode active material layer 22 is referred to as “negative electrode slurry”. The positive electrode slurry contains the above-described positive electrode active material, conductive additive, binder, thickener, and the like. The slurry for negative electrode contains the above-mentioned negative electrode active material, conductive additive, binder, thickener and the like. The solvent for the slurry may be any solvent that dissolves the binder and the thickener and disperses the active material and the conductive additive.

Next, the positive electrode current collector 30 and the negative electrode current collector 20 are prepared.
Then, a positive electrode slurry is applied to both surfaces of the positive electrode current collector 30. Thereafter, the positive electrode slurry is dried. Thereby, the positive electrode active material layer 32 is formed on both surfaces of the positive electrode current collector 30 to obtain a positive electrode sheet. And the sheet | seat for positive electrodes is cut out in the strip | belt shape mentioned above with the slitter etc., and the positive electrode 5 is obtained (electrode processing process S1, S11).

On the other hand, the negative electrode slurry is applied to both surfaces of the negative electrode current collector 20. Thereafter, the negative electrode slurry is dried. Thereby, the negative electrode active material layer 22 is formed on both surfaces of the negative electrode current collector 20 to obtain a negative electrode sheet. Then, the negative electrode sheet is cut into the above-described belt shape with a slitter or the like to obtain the negative electrode 3.
In the electrode processing step S1 (that is, before the electrode coating steps S2 and S12), the outer shape of the positive electrode 5 is made smaller than the outer shape of the negative electrode 3.

  Next, as shown in FIG. 7, the positive electrode 5 is sandwiched and covered by the first separator 41 and the second separator 42 constituting the separator 6, and these are heat-welded and integrated (electrode coating step S2, S12). The first separator 41 and the second separator 42 have a rectangular shape extending in the longitudinal direction of the positive electrode 5 in the unfolded state (plan view in FIG. 7). In addition, the external shape of the 1st separator 41 and the 2nd separator 42 should just be a magnitude | size of the grade which covers the electrode connection part 5a and the positive electrode main body 5b in the positive electrode 5, and the extension part 31 is exposed. A positive electrode structure 4 in which the positive electrode 5 and the separator 6 are integrated by heat fusion is obtained.

  The first separator 41, the second separator 42, and the positive electrode 5 are thermally fused to obtain the positive electrode structure sheet 4A shown in FIG. Then, the positive electrode structure sheet 4A is cut out in the above-described band shape with a slitter or the like to obtain the positive electrode structure 4 shown in FIG. At this time, in the developed state, the outer shape of the positive electrode structure 4 is made substantially the same as the outer shape of the negative electrode 3.

  Next, the positive electrode structure 4 and the negative electrode 3 are combined so as to be stacked alternately (electrode combination process: S3, S13), and then folded in a zigzag shape in a direction intersecting each other (zigzag folding process: S4, S14).

If the positive electrode structure 4 and the negative electrode 3 are obtained, they are folded and overlapped to form the overlapping unit 2A and the overlapping unit 2B.
For example, the overlapping unit 2A employs a zigzag folding structure from the overlapping shown in FIG. 9A, and the overlapping unit 2B employs a zigzag folding structure from the overlapping shown in FIG. 9B, for example.
9A and 9B, bent portions of the positive electrode structure 4 are denoted by reference numerals T1 to T5 (chain lines), and bent portions of the negative electrode 3 are denoted by reference numerals U1 to U5 (chain lines).

As shown in FIG. 9A, first, an overhang portion (ie, an overhang portion 6b of the separator 6) provided with an extension portion 31 in the longitudinal direction of the positive electrode structure 4 and an extension in the longitudinal direction of the negative electrode 3 are provided. The negative electrode body 3b provided with the portion 21 is overlapped in an L shape in plan view so that the positive electrode structure 4 and the negative electrode 3 are orthogonal to each other. In FIG. 9A, the negative electrode body 3b of the negative electrode 3 is placed on the overhanging portion 6b of the separator 6 of the positive electrode structure 4 (electrode combination step: S3).
From this state, the positive electrode main body (ie, the protruding portion 6b of the separator 6) of the positive electrode structure 4 and the negative electrode main body 3b of the negative electrode 3 are successively folded and alternately overlapped to form the overlapping unit 2A.

As shown in FIG. 9B, first, the positive electrode main body (that is, the protruding portion 6b of the separator 6) provided with the extending portion 31 in the longitudinal direction of the positive electrode structure 4, and the negative electrode 3 extending in the longitudinal direction. The negative electrode body 3b provided with the portion 21 is overlapped in an L shape in plan view so that the positive electrode structure 4 and the negative electrode 3 are orthogonal to each other. In FIG. 9B, the overhanging portion 6b of the separator 6 of the positive electrode structure 4 is installed on the negative electrode main body 3b of the negative electrode 3 (electrode combination step: S13).
From this state, the negative electrode main body 3b and the positive electrode main body (that is, the overhanging portion 6b of the separator 6) are sequentially folded and alternately folded to form the overlapping unit 2B.

9A and 9B are stacked as shown in FIG. 2 (stacking unit stacking step: S5), and electrode terminal connection (to be described later) ( The laminated body 2 can be comprised by performing electrode terminal connection process: S6).
When stacking the overlapping units 2A and 2B, the positive electrode terminal 31 of the positive electrode structure 4 is disposed on the bottom side of the overlapping unit 2A, and the negative electrode terminal 21 of the negative electrode 3 is disposed on the upper side of the overlapping unit 2B. To do.

  That is, the overlapping unit 2B is arranged inside the exterior body 10 in the state shown in FIG. 5A, and the overlapping unit 2A is turned upside down from the state shown in FIG. Placed in. As a result, as shown in FIG. 10, the positive electrode terminal 31 of the superposition unit 2A and the positive electrode terminal 31 of the superposition unit 2B are vertically opposed to each other, and the negative electrode terminal 21 of the superposition unit 2A and the superposition unit 2B The negative electrode terminals 21 are arranged opposite to each other in the vertical direction.

The superposition unit 2A and the superposition unit 2B can be connected by connecting the positive electrode terminals 31 and the negative electrode terminals 21 facing each other vertically (S6; electrode terminal connection step).
Since the negative electrode body 3b of the negative electrode 3 is disposed on the uppermost surface of the overlapping unit 2A, the overlapping unit 2B is disposed on the negative electrode can body 12 side, and the overlapping unit 2B is disposed on the lowermost surface of the separator 6 of the positive electrode structure 4 on the protruding portion 6b. Is arranged on the positive electrode can body 11 side.

Then, after impregnating the laminate 2 with an electrolyte solution (not shown), the laminate 2 impregnated with the electrolyte solution is enclosed in the exterior body 10 to complete the battery 1 (see FIG. 2) of the present embodiment. .
In the battery 1 configured as described above, the superposition unit 2A and the superposition unit 2B, which are vertically opposed to each other, are connected to the positive electrode can body 11 by connecting the positive electrode terminals 31 led out from the close position of the superposition unit 2B. it can.

Moreover, the negative electrode terminal body 21 can be connected to the negative electrode can body 12 by connecting the negative electrode terminal 21 led out from a position close to the superposition unit 2 </ b> A and the superposition unit 2 </ b> B that are opposed to each other.
In these connection structures, if the positive electrode terminals 31 and 31 and the negative electrode terminals 21 and 21 are derived from positions close to the overlapping portions of the overlapping units 2A and 2B, the positive electrode terminal 31 is connected to the positive electrode can body 11. Even if the negative electrode terminal 21 is connected to the negative electrode can body 12, the connection can be made at the same distance. For example, with the connection structure of FIG. 11, terminal connection can be made at the same distance on the positive electrode side and the negative electrode side.

  The electrode terminals 21 and 31 can be arranged not on the boundary between the overlapping units 2A and 2B but also on the positive electrode can body 11 side or the negative electrode can body 12 side, but this arrangement corresponds to the side surface height of the laminate 2. Lead wiring is required. Since it is not desirable to route the electrode terminals over the entire length of the side surface of the laminate 2, it is desirable to employ the structure described above, such as the connection structure shown in FIG.

  DESCRIPTION OF SYMBOLS 1 ... Battery, 2 ... Laminated body, 2A, 2B ... Overlay unit, 3 ... Negative electrode, 3a ... Electrode connection part, 3b ... Negative electrode main body (overhang | projection part), 4 ... Positive electrode structure, 5 ... Positive electrode, 5a ... Electrode connection part, 5b ... Positive electrode body (overhang part), 6 ... Separator, 6a ... Electrode connection part, 6b ... Overhang part, 10 ... Exterior body, 11 ... Positive electrode body, 12 ... Negative electrode body, 13 ... Gasket, 20 DESCRIPTION OF SYMBOLS ... Negative electrode collector, 21 ... Negative electrode terminal (extension part), 22 ... Negative electrode active material layer, 30 ... Positive electrode collector, 31 ... Positive electrode terminal (extension part), 32 ... Positive electrode active material layer, 41 ... 1st separator, 42 ... 2nd separator, S1, S11 ... Electrode processing step, S2, S12 ... Electrode coating step, S3, S13 ... Electrode combination step, S4, S14 ... Spiral folding step, S5 ... Overlapping unit lamination step, S6 ... Electrode terminal connection step.

Claims (11)

A plurality of positive electrode bodies arranged side by side, and a strip-like positive electrode electrode having an electrode connection part for connecting two adjacent positive electrode bodies;
A plurality of negative electrode bodies arranged side by side, and a strip-shaped negative electrode having an electrode connection part for connecting two adjacent negative electrode bodies;
Comprising a separator disposed between the positive electrode and the negative electrode;
The positive electrode body and through the separator the anode body, alternately superimposed zigzag, folded the electrode connecting portions individually on the outside of the outer and the negative electrode body of the positive electrode body, the negative electrode and the positive electrode The alternate stacking type superposition unit of
While a plurality of the overlapping units are stacked and connected to each other in parallel ,
The separator has a strip shape including a plurality of overhang portions arranged side by side and a connection portion that connects two adjacent overhang portions.
The front and back surfaces of the plurality of positive electrode bodies of the positive electrode are covered by the overhang portions of the separator, and the front and back surfaces of the electrode connection portions of the positive electrode are covered by the connection portions of the separator, thereby forming a positive electrode structure.
The electrochemical cell, wherein the superposition unit is configured by alternately laminating the positive electrode structure and the negative electrode .  2. The electrochemical cell according to claim 1, wherein the outer peripheral contour of the positive electrode main body is arranged inside the outer peripheral contour of the negative electrode main body viewed along the overlapping direction in the one superposition unit. The lengths of the plurality of electrode connection portions in the positive electrode are the same, and the lengths of the plurality of electrode connection portions in the negative electrode are the same,
The outer peripheral contour of the positive electrode body viewed along the overlapping direction in the one overlapping unit is displaced for each overlapping layer, and the outer peripheral contour of the positive electrode body is the negative electrode body in the layer having the largest positional displacement amount. The electrochemical cell according to claim 1, wherein the electrochemical cell is disposed inside an outer peripheral contour of the electrode.  In the belt-like positive electrode and the belt-like negative electrode, the positional deviation amount of each outer peripheral contour viewed along the superposition direction of the positive electrode main body and the negative electrode main body is increased from the start side to the end side of the superposition. The electrochemical cell according to any one of claims 1 to 3, wherein the electrochemical cell is characterized.  In the stacked adjacent overlapping unit, the positive electrode side connection electrode terminal is derived from the closest positive electrode of one superposition unit and the other superposition unit, these positive electrode side connection electrode terminals are connected, The negative electrode side connection electrode terminals are led out from the closest negative electrode electrodes of one overlapping unit and the other overlapping unit, and these negative electrode side connection electrode terminals are connected to each other. 5. The electrochemical cell according to any one of 4. In at least one of the positive electrode and the negative electrode, the starting end side of the connecting portion of the overlapping end side of the connecting portion of the superposition than the length of the claims 1 to 5, characterized in that is longer in length The electrochemical cell as described in any one. A belt-like positive electrode having a plurality of positive electrode bodies arranged side by side and an electrode connecting part for connecting two adjacent positive electrode bodies;
A strip-shaped negative electrode having a plurality of negative electrode bodies arranged side by side and an electrode connecting portion for connecting two adjacent negative electrode bodies,
Via the separator between the positive electrode main body and the negative electrode main body, the electrode connecting portions are folded individually on the outer side of the positive electrode main body and the outer side of the negative electrode main body, and alternately stacked in a zigzag manner so as to overlap the positive electrode and the negative electrode When constructing an alternate stacking type superposition unit, stacking a plurality of these superposition units and connecting them in parallel ,
The separator has a strip shape including a plurality of overhang portions arranged side by side and a connection portion that connects two adjacent overhang portions.
Covering the front and back surfaces of the plurality of positive electrode bodies of the positive electrode with the protruding portion of the separator, and covering the front and back surfaces of the electrode connection portion of the positive electrode with the connection portion of the separator,
The method for producing an electrochemical cell, wherein the superposition unit is configured by alternately laminating the positive electrode structure and the negative electrode .  8. The electrochemical cell according to claim 7, wherein the superposition is performed so that the outer peripheral contour of the positive electrode main body is placed inside the outer peripheral contour of the negative electrode main body viewed along the overlapping direction in the one superposition unit. Manufacturing method. Using a positive electrode having the same length of the plurality of electrode connection portions and a negative electrode having the same length of the plurality of electrode connection portions,
The outer peripheral contour of the positive electrode body in the layer with the largest amount of positional deviation is such that the outer peripheral contour of the positive electrode body viewed along the overlapping direction in the one overlapping unit is displaced for each overlapping layer. The method for producing an electrochemical cell according to claim 7 or 8, wherein the superposition is performed so as to be inside the outer peripheral contour of the negative electrode main body.  In the belt-like positive electrode and the belt-like negative electrode, the positional deviation amount of each outer peripheral contour seen along the superposition direction of the positive electrode main body and the negative electrode main body is increased from the start side to the end side of the superposition. The method for producing an electrochemical cell according to any one of claims 7 to 9, wherein the electrochemical cell is superposed on each other.  When laminating the superposition unit, a positive electrode side connection electrode terminal is derived from the closest positive electrodes of one superposition unit and the other superposition unit, and the positive electrode side connection electrode terminals are connected to each other. 11. The negative electrode side connection electrode terminal is derived from the nearest negative electrode of the superposition unit of the other and the other superposition unit, and these negative electrode side connection electrode terminals are connected to each other. The manufacturing method of the electrochemical cell as described in any one.

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