JP6592495B2 - Electrochemical cell and method for producing electrochemical cell - Google Patents

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.
For example, when laminating a plurality of zigzag folded electrodes, the next electrode is folded so as to circulate the next lower electrode, so that the wraparound error during wrapping, the bending portion error during zigzag folding, the stacking positioning error, etc. Are accumulated, and 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-mentioned problem, an electrochemical cell according to an embodiment of the present invention has a plurality of positive electrode main bodies arranged side by side and an electrode connecting portion connecting two adjacent positive electrode main bodies. A positive electrode, a plurality of negative electrode bodies arranged side by side, a bead-connected negative electrode having an electrode connecting portion for connecting two adjacent negative electrode bodies, and the positive electrode and the negative electrode A negative electrode or a positive electrode connected to either the L-shape or the U-shape, either or both of the daisy chain-like positive electrode body and the daisy chain-like negative electrode body, A reference overlapping portion is configured by superimposing one or two negative electrodes of the daisy chain-shaped intermediate portion on one or two of the positive electrodes of the daisy-chain intermediate portion via the separator. With the reference overlapping portion as a reference, the bead-connected positive electrode and the bead-connected negative electrode are alternately stacked in a folded manner via the separator on the one side, and the bead-connected positive electrode and the bead-connected shape on the other side. The negative electrodes are alternately stacked in a folded manner with the separator interposed therebetween.

  If the reference overlapping part that overlaps the middle part of the daisy chain-shaped positive electrode body or the negative electrode body is used as a boundary, if it is made to be individually folded in one side and the other side, the positive electrode body facing the one side It is possible to employ a structure in which the amount of positional deviation does not affect the amount of positional deviation of the facing position of the positive electrode main body that occurs at the other side of the folded portion. If the misalignment amounts of the zigzag folded part on one side and the zigzag folded part on the other side are reduced, the facing position misalignment amount of the positive electrode main body can be reduced as the entire laminated structure.

In this regard, when all the positive electrode bodies to be stacked are connected and stacked in a folded manner sequentially from the end side, the positional deviations are sequentially accumulated and increased from the starting end side to the terminal end side. 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.
By reducing the amount of misalignment of the positive electrode body that occurs between the zigzag folded part on one side and the zigzag folded part on the other side, it is possible to suppress the misalignment of the positive electrode body in the case of the entire laminated structure. 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.

[2] In the electrochemical cell according to the one aspect, a rosary-link shape including a protruding portion that covers the front and back surfaces and the peripheral surface of the positive electrode body of the positive electrode, and a connection portion that covers the front and back surfaces and the peripheral surface of the electrode connection portion. The positive electrode is covered with the separator, and the outer peripheral contour of the protruding portion of the separator and the outer peripheral contour of the negative electrode main body of the negative electrode are aligned in the zigzag folded state, and in the overlapping portion of the positive electrode and the negative electrode, A configuration in which the outer peripheral contour of the positive electrode main body is disposed inside the outer peripheral contour of the negative electrode main body viewed along the overlapping direction can be employed.

In the stacked 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.
For this reason, the structure which covers the said positive electrode with the separator which has the overhang | projection part which covers the front and back and peripheral surface of the said positive electrode main body is employ | adopted, and the outer peripheral outline of the overhang | projection part of a separator and the outer periphery outline of the said negative electrode main body are piled up in a folded state. It is preferable to align.

[3 ] An electrochemical cell according to an embodiment of the present invention includes a plurality of positive electrode bodies arranged side by side, and a daisy chain-like positive electrode having electrode connection portions that connect two adjacent positive electrode bodies. A plurality of negative electrode bodies arranged, a daisy chain-like negative electrode electrode having an electrode connecting part for connecting two adjacent negative electrode bodies, and a separator arranged between the positive electrode and the negative electrode, The lengths of the plurality of electrode connection portions in the positive electrode are the same, the lengths of the plurality of electrode connection portions in the negative electrode are the same, and one or two of the positive electrodes in the middle of the daisy chain One or two negative electrodes in the middle part of the daisy chain are overlapped via the separator to form a reference overlapping part, and the rosary connecting form is formed on one side with reference to the reference overlapping part. The positive electrode and the bead-connected negative electrode are alternately stacked in a zigzag manner via the separator, and the other side of the bead-like positive electrode and the bead-connected negative electrode are alternately stacked in a zigzag manner via the separator is, the outer peripheral contour of the overlapping said cathode body as seen along the direction is positional deviation for each layer superposed, the positional shift amount is the outer peripheral edge of the cathode body at a maximum layer of the outer peripheral contour of the negative electrode body It is arranged inside .

  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. The outer peripheral contour of the positive electrode main body is arranged inside the outer peripheral contour of the negative electrode body even in the overlapping layer on one side and the other side with the reference overlapping portion as a boundary, even in the layer with the largest positional deviation amount. These problems can be avoided.

If the lengths of the electrode connection part and the electrode connection part are the same when the superposed positive and negative electrode bodies are alternately overlapped from the end part, the negative electrode is caused by an overlay error, etc. The overlapping position of the positive electrode main body with respect to the main body gradually shifts.
Instead of simply superimposing the positive electrode body and the negative electrode body alternately, a reference overlapping portion is formed by overlapping a negative electrode in the middle part of the daisy chain with the positive electrode in the middle part of the daisy chain. A zigzag fold structure is formed in a zigzag shape on one side and a zigzag shape on the other side. As a result, the number of zigzag folds on one side of the reference overlapping portion and the number of zigzag folds on the other side can be made smaller than the total number of zigzag folds on the other side. it can.

"4" In the electrochemical cell of the one aspect, in the superposition of the positive electrode and the negative electrode on one side with respect to the reference superposition portion, the positive electrode main body and The amount of positional deviation of each outer peripheral contour seen along the superposition direction of the negative electrode body is increased, and in the superposition of the positive electrode and the negative electrode to the other side, from the start side to the end side of the superposition, It is possible to adopt a configuration in which the amount of positional deviation of each outer peripheral contour viewed along the overlapping direction of the positive electrode main body and the negative electrode main body is increased.

  If the structure is such that the daisy-chained positive electrode and the strip-shaped negative electrode are overlapped while being zigzag, if the length of the electrode connections is the same, the amount of misalignment of the positive electrode body will increase as the number of overlap increases. Become. Even in this structure, if the amount of misalignment of the positive electrode body is individually suppressed on one side and the other side of the reference overlapping portion, the accumulation of the amount of misalignment of the positive electrode body can be reduced. It is possible to provide an electrochemical cell in which the amount of misregistration is suppressed.

[5 ] An electrochemical cell according to an embodiment of the present invention includes a plurality of positive electrode bodies arranged side by side, and a daisy chain-like positive electrode having electrode connection portions that connect two adjacent positive electrode bodies. A plurality of negative electrode bodies arranged, a daisy chain-like negative electrode electrode having an electrode connecting part for connecting two adjacent negative electrode bodies, and a separator arranged between the positive electrode and the negative electrode, A reference overlapping portion is formed by superimposing one or two negative electrodes of the rosary connecting intermediate portion on one or two of the positive electrodes in the intermediate connecting portion of the rosary via the separator. As a reference, the bead-like positive electrode and the bead-like negative electrode are alternately stacked in a folded manner through the separator on one side, and the bead-like positive electrode on the other side and the front Randomly connected negative electrodes are alternately stacked in a folded manner with the separator interposed therebetween, and the positive electrode and the negative electrode are overlapped on one side with respect to the reference overlapping portion as a reference from the starting end side of the overlapping to the terminal side In this case, the positional deviation amount of each outer peripheral contour viewed along the overlapping direction of the positive electrode main body and the negative electrode main body is increased, and in the overlapping of the positive electrode electrode and the negative electrode to the other side, the start end side of the overlapping Further, the positional deviation amount of each outer peripheral contour viewed along the overlapping direction of the positive electrode main body and the negative electrode main body is increased on the terminal side .
[6] In the electrochemical cell of the one aspect, 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 overlapping portion of the positive electrode and the negative electrode. Can be adopted.
[7] In the electrochemical cell of the one aspect, either one or both of the daisy chain positive electrode main body and the daisy chain negative electrode main body are connected in any one of a linear shape, an L shape, and a U shape. A negative electrode or a positive electrode is preferred.
“8” In the electrochemical cell of the one aspect, a configuration in which connection electrode terminals are led out to either one or both of a folded portion toward one side and a folded portion toward the other side with respect to the reference overlapping portion. Can be adopted.

  The connection electrode terminal can be derived from one or both of the one side folded portion and the other side folded portion of the reference overlapping portion. These connection electrode terminals can be used to connect to a can that accommodates an electrochemical cell. Moreover, the connection distance from the connection electrode terminal derived from the negative electrode body or the connection electrode terminal derived from the positive electrode body to the can can be adjusted by adjusting the lead position of the connection electrode terminal. For this reason, the positive connection and the negative electrode can be reliably connected to the can through the connection electrode terminals. Moreover, when connecting the connection electrode terminal to the can on the positive electrode side and the negative electrode side, the amount of protrusion of these connection electrode terminals to the side can be reduced by selecting an appropriate lead-out position. As a result, the zigzag folded structure can be accommodated in the can without gaps, and an electrochemical cell having a lean structure can be provided.

[6] In the electrochemical cell of the one aspect, either one or both of the daisy chain positive electrode main body and the daisy chain negative electrode main body are connected to one of a linear shape, an L shape, and a U shape. A configuration that is a negative electrode or a positive electrode can be employed.

  The shape of the daisy chain-shaped positive electrode main body and negative electrode main body may be any shape such as a linear shape, an L shape, or a U shape. Regardless of the shape, a reference superposition part is formed by overlapping the two in the middle, and a target electrochemical cell can be constituted by forming a folded structure on one side and the other side with the reference superposition part as a boundary. .

“9” A method for producing an electrochemical cell according to an aspect of the present invention includes a plurality of positive electrode bodies arranged side by side and a daisy chain-like positive electrode having an electrode connection part that connects two adjacent positive electrode bodies; A plurality of negative electrode bodies arranged side by side and a daisy chain-like negative electrode having an electrode connection part for connecting two adjacent negative electrode bodies are used, and the rosary chain is connected to one or two positive electrodes in the middle part of the daisy chain one or two negative electrode shaped for middle portions superposed over the separators to constitute a reference composition unit, based on the reference overlapping portions, the daisy-chain-like positive electrode and the strung like on one side The negative electrodes are alternately stacked in a folded manner through the separator, and the daisy chain positive electrode and the daisy chain negative electrode are alternately disposed on the other side through the separator. Characterized by laminating Zura folding shape.

  By adopting a structure that folds separately on one side and the other side with the reference overlapping portion as a boundary, it is possible to have a configuration that does not affect the amount of misalignment that occurs in the one side fold portion and the other side fold portion. . If the misalignment amount of the individual zigzag folded portions on one side and the other side is reduced, the misalignment amount of the positive electrode body as the entire laminated structure can be reduced.

In this regard, when a structure in which all the positive electrode bodies to be stacked are connected from the end side of the daisy chain and are sequentially overlapped, the positional deviation is sequentially accumulated and increased from the start end side to the end side. 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 zigzag fold by reducing the misalignment that occurs in the zigzag folded part on one side and the zigzag folded part on the other side. The amount of deviation can be suppressed.

[ 10] In the method for manufacturing an electrochemical cell according to the one aspect, in the overlapping portion of the positive electrode and the negative electrode, the outer periphery of the positive electrode main body is located inside the outer peripheral contour of the negative electrode main body as viewed along the overlapping direction. It is preferable to arrange the contour.

  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.

[ 11] In the method of manufacturing an electrochemical cell according to the aspect, the reference electrode includes 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 positional deviation is performed so that the outer peripheral contour of the positive electrode body seen along the superposition direction is misaligned for each superposition layer in superposition to one side with reference to one side and the other side of the superposition part. In the layer with the largest amount, the outer peripheral contour of the positive electrode main body is overlapped so that the outer peripheral contour of the positive electrode main body is inside the outer peripheral contour of the negative electrode main body. Are preferably overlapped so that the outer peripheral contour of the positive electrode main body is inside the outer peripheral contour of the negative electrode main body in the layer having the largest amount of displacement.

  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. By adopting a structure that folds separately on the front side and the back side with the reference overlapping part as a boundary, it becomes easier to make the outer peripheral contour of the positive electrode body inside the outer peripheral contour of the negative electrode body, and the electrolyte component precipitation It is possible to provide an electrochemical cell that can eliminate the fear and cause no risk of capacity reduction.

[ 12] In the electrochemical cell manufacturing method of the one aspect, in the superposition of the positive electrode and the negative electrode on one side with respect to the reference superposition portion, the superposition from the start side to the end side of the superposition, In the superposition of the positive electrode main body and the negative electrode main body so that 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 increases, It is preferable to overlap the positive electrode main body and the negative electrode main body so as to increase the positional deviation amount of each outer peripheral contour as viewed along the overlapping direction of the positive electrode main body and the negative electrode main body.

  If the structure is such that the daisy-chained positive electrode and the daisy-chained negative electrode are stacked while being folded, the number of overlapping increases when the electrode connection portions have the same length and the electrode connection portions have the same length. Every time, the amount of misalignment of the positive electrode main body is accumulated and increased. Even if this structure is adopted, it is possible to accumulate the amount of misalignment of the positive electrode body by adopting a structure that folds separately on one side and the other side with the reference overlapping portion as a boundary, so that each misregistration amount is suppressed. As a result, it is possible to provide an electrochemical cell in which the amount of displacement is suppressed.

[ 13] In the method of manufacturing an electrochemical cell according to the one aspect, a connection electrode terminal is led out to one or both of a zigzag folded portion to one side and a zigzag folded portion to the other side with the reference overlapping portion as a reference. It is preferable.

  The connection electrode terminal can be derived from the zigzag folded part on one side and the zigzag folded part on the other side of the reference overlapping part. By using these connection electrode terminals, it is possible to connect to a can that accommodates the electrochemical cell. Moreover, the connection distance from the connection electrode terminal derived from the negative electrode body or the connection electrode terminal derived from the positive electrode body to the can can be adjusted by adjusting the lead position of the connection electrode terminal. For this reason, the positive connection and the negative electrode can be reliably connected to the can through the connection electrode terminals. Moreover, when connecting the connection electrode terminal to the can on the positive electrode side and the negative electrode side, the amount of protrusion of these connection electrode terminals to the side can be reduced by selecting an appropriate lead-out position. As a result, the zigzag folded structure can be accommodated in the can without gaps, and an electrochemical cell having a lean structure can be provided.

[ 14] In the method of manufacturing an electrochemical cell according to the one aspect, either or both of the daisy chain positive electrode main body and the daisy chain negative electrode main body are linear, L-shaped, or U-shaped. A connected negative electrode or positive electrode is preferred.

  According to the present embodiment, if the reference overlapping portion where the intermediate portions of the daisy chain-like positive electrode main body or negative electrode main body are overlapped is used as a boundary, the one side and the other side are individually folded in a fold shape, the one side has a fold-folded portion. It is possible to employ a structure in which the amount of positional deviation of the facing position of the positive electrode main body does not affect the amount of positional deviation of the facing position of the positive electrode main body occurring in the other side of the folded portion. By reducing the amount of misalignment between the zigzag folded part on one side and the zigzag folded part on the other side, it is possible to provide an electrochemical cell in which the misalignment amount of the positive electrode main body is reduced as the entire laminated structure.

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. It is a perspective view which shows an example of the laminated body integrated in the battery which concerns on 1st Embodiment. It is a perspective view which shows an example of the positive electrode structure incorporated in the battery. 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. It is explanatory drawing which shows the state which overlap | superposed the positive electrode structure and negative electrode structure which are used when comprising the laminated body shown in FIG. 3, and comprised the reference | standard overlap | superposition part. FIG. 8 is an explanatory diagram illustrating a state in which a part of the positive electrode structure and the negative electrode structure is folded from the state illustrated in FIG. 7. It is description which shows an example of the positive electrode structure incorporated in the battery which concerns on 2nd Embodiment, and a negative electrode structure. FIG. 10 is an explanatory diagram illustrating a state in which a reference overlapping portion is configured by overlapping the positive electrode structure and the negative electrode structure illustrated in FIG. 9. It is explanatory drawing which shows the state which folded the positive electrode structure and a part of negative electrode structure from the state shown in FIG. It is description which shows an example of the positive electrode structure incorporated in the battery which concerns on 3rd Embodiment, and a negative electrode structure. It is explanatory drawing which shows the state which overlap | superposed the positive electrode structure shown in FIG. 12 and the negative electrode structure, and comprised the reference | standard overlapping part. It is explanatory drawing which shows the state which folded the positive electrode structure and a part of negative electrode structure from the state shown in FIG. It is description which shows an example of the positive electrode structure incorporated in the battery which concerns on 4th Embodiment, and a negative electrode structure. 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 laminate 2, an electrolyte solution (not shown) impregnated in the laminate 2, and an exterior body 10 that houses the laminate 2.

[Laminate]
As shown in FIG. 3, the laminate 2 includes a negative electrode 3 folded in a zigzag shape, and a positive electrode structure folded in a zigzag shape in a direction intersecting the negative electrode 3 so as to be alternately laminated with the negative electrode 3. 4 is provided. The outline of the structure of only the positive electrode structure 4 is shown in FIG.

[Negative electrode]
The negative electrode 3 in a state of being expanded from a zigzag shape has a band shape, and has a shape in which a plurality of electrode connection portions 3a and a plurality of overhang portions (negative electrode main bodies) 3b are connected in a daisy chain shape, as shown in FIG. The main body 3b is folded so as to overlap a positive electrode main body 5b described later.
In addition, the positive electrode 5 mentioned later is also formed in the shape of a daisy chain similarly to the negative electrode 3, and is folded in a zigzag manner.

  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. 3, an extended portion (negative electrode terminal) 21 of the negative electrode current collector 20 is formed at one end 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 FIGS. 3 and 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]
When the positive electrode 5 is unfolded, it has a strip shape as shown in FIG. More specifically, the positive electrode 5 has a plurality of electrode connection portions 5a and a plurality of positive electrode main bodies 5b connected in a daisy chain. 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. 5, 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 through 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 5, an extension portion (positive electrode terminal) 31 of the positive electrode current collector 30 is formed at one end portion 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. 5, 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. 6 by heat fusion. In FIG. 5, the first separator 41 and the second separator 42 in a state where the pair of the first separator 41 and the second separator 42 are cut out to have substantially the same size as the outer shape of the negative electrode 3 are shown. .

[Laminate]
The laminated body 2 of the present embodiment is formed by laminating the positive electrode structure 4 including the separator 6 having the configuration shown in FIG. 5 and the negative electrode 3 having an outline similar to that of the separator 6 in a plan view so as to alternately overlap each other. Is made up of.
When the laminate 2 is viewed in plan along the stacking direction as shown in FIG. 3, 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.

  The laminated body 2 of the present embodiment is configured by bending the negative electrode 3 and the positive electrode structure 4 so as to overlap each other except for a part. When the laminate 2 is viewed in plan along the stacking direction as shown in FIG. 3, the circular outer peripheral contour of the positive electrode main body 5 b is arranged inside the circular outer peripheral contour of the negative electrode main body 3 b of the negative electrode 3. . This arrangement relationship is the same in all the positive electrode bodies 5b of the stacked body 2.

FIG. 7 shows an example of a state in which the zigzag folded structure composed of the negative electrode 3 and the positive electrode structure 4 is developed in the laminate 2 of the present embodiment. In other words, FIG. 7 shows a state before the negative electrode 3 and the positive electrode structure 4 are folded into a zigzag structure.
In this example, as shown in FIG. 7, the strip-like positive electrode structure 4 is horizontally arranged with the positive electrode terminal 31 on the left side, and the inverted U-shaped negative electrode 3 is superimposed on the positive electrode structure 4. The positive electrode terminal 31 shown in FIG. 7 is exaggerated longer than the positive electrode terminal 31 shown in FIG.

In this example, the positive electrode structure 4 includes 12 positive electrode main bodies 5b connected in a row in a row, and a positive electrode terminal 31 is formed on the left end side. The negative electrode 3 is connected in an inverted U-shape by providing two rows of six rows of negative electrode main bodies 3b connected in a row. The negative electrode body 3b on one end side of the first row of the negative electrode 3 is connected to the negative electrode body 3b on the one end side of the second row so that the negative electrode 3 is formed in an inverted U shape and the other end of the first row A negative electrode terminal 21 is formed on the negative electrode body 3b on the side. The negative electrode terminal 21 shown in FIG. 7 is exaggerated longer than the negative electrode terminal 21 shown in FIG.
Further, the outer shape of the overhanging portion 6b of the separator 6 provided in the positive electrode structure 4 and the outer shape of the negative electrode body 3b formed in the negative electrode 3 are essentially the same, but in FIG. For ease of illustration, the outer shape of the overhanging portion 6b is drawn slightly smaller than the outer shape of the negative electrode body 3b.

  As shown in FIG. 7, the first row in the first row is placed on the sixth positive electrode body 5b (exactly on the overhanging portion 6b of the separator 6) from the left end side (side on which the positive electrode terminal 31 is formed). The negative electrode main body 3b is overlaid, and the negative electrode main body 3b on the one end side of the second row is overlaid on the seventh positive electrode main body 5b (more precisely, on the overhanging portion 6b of the separator 6). In other words, the two negative electrode main bodies 3b on one end side of the inverted U-shaped negative electrode 3 are overlapped in a central portion (intermediate portion) of the positive electrode structure 4 in the form of a row of beads connected in a T-shape. The overlapped portion is a reference overlapping portion a.

  In the state shown in FIG. 7, the six positive electrode bodies 5b on the right side of the reference overlapping portion a and the six negative electrode bodies 3b on the right row side (second row) are arranged in an inverted L shape. For this reason, from the state shown in FIG. 7, the positive electrode bodies 5b and the negative electrode bodies 3b can be alternately folded, so that the six positive electrode bodies 5b on the right side and the six negative electrode bodies 3b on the right column side can be folded. In FIG. 7, the positive electrode main body 5b and the negative electrode main body 3b can be alternately spelled in the order shown in (1), (2), and (3). .

Next, in the state shown in FIG. 7, the six positive electrode bodies 5b on the left side of the reference overlapping portion a and the six negative electrode bodies 3b on the left column side (first column) are arranged in an inverted L shape. From the state shown in FIG. 7, by alternately folding the positive electrode main body 5b and the negative electrode main body 3b, the six positive electrode bodies 5b on the left side and the six negative electrode bodies 3b on the left column side can be folded.
When the right zigzag folding and the left zigzag folding are completed, the stacked body 2 shown in FIGS. 2 and 3 is obtained by folding the positive electrode bodies 5b of the reference overlapping portion a.

Note that the stacked body 2 shown in FIG. 3 and the zigzag-shaped positive electrode structure 4 shown in FIG. 4 are drawn as models of an ideally zigzag folded structure. 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 omitted in FIGS. 2 to 4, in the laminated body 2, strictly, the positive electrode main body 5 b is misaligned for each layer folded and overlapped.

However, in the laminate 2 of the present embodiment, when viewed in plan along the overlapping direction, the negative electrode main body 3b even if the circular outer peripheral contours of all the positive electrode main bodies 5b have some positional deviation. It is arrange | positioned inside the circular outer periphery outline. Further, in the laminate 2, the negative electrode body 3 b of the negative electrode 3, even when the circular outer peripheral contours of all the positive electrode bodies 5 b have some positional deviation when viewed in plan along the overlapping direction. It is arrange | positioned inside the circular outer periphery outline.
The reason why the positional deviation in the stacked body 2 can be reduced in this way is that a structure in which the sheet is folded individually on one side and the other side with the reference overlapping portion a as a boundary is employed. 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. 2 and 3 together, the positive electrode can body 11 is connected to the extending portion 31 of the positive electrode current collector 30, 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 and functions as a negative electrode terminal. In FIG. 2, illustration of the electrode terminals 21 and 31 connected to the positive electrode can body 11 and the negative electrode can body 12 is omitted.

In the battery 1 of the present embodiment, a structure in which the laminated body 2 is individually folded on the one side and the other side, in other words, the front side and the back side via the reference overlapping portion a is adopted.
The laminated body 2 has the following characteristics by having a structure in which the front side and the back side are individually folded via the reference overlapping portion a.

  In the case of a structure in which the number of stacked layers in the stacked body is large, assuming that the electrode connecting portions 3a and 5a have the same length, the center position of the positive electrode body 5b is gradually positioned with respect to the center position of the negative electrode body 3b at each stacking. Deviation occurs. This is because the stacked body gradually becomes thicker due to the stacking of the negative electrode body 3b and the positive electrode body 5b stacked when zigzag folding, the influence of the bending 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.
2 to 4, 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 laminations of the positive electrode body 5b and the negative electrode body 3b is as small as 6 to 8 layers, the amount of misalignment is small, but when the number of laminations is larger than these, the amount of misalignment cannot be ignored. Depending on the number of 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 regard, when adopting a structure in which the front side and the back side are individually folded through the reference overlapping portion a provided in the middle of the rosary connection, the amount of misregistration can be accumulated as compared with the case of sequentially bending from the end of the rosary connection. Can be reduced. 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 the present embodiment, the amount of positional deviation of the facing position of the positive electrode body 5b generated on the front side of the reference overlapping portion a is the amount of positional deviation of the facing position of the positive electrode body 5b generated on the back side. The structure has no effect. Therefore, if the amount of misalignment of each positive electrode body 5b generated on the front side and the back side of the reference overlapping portion a is reduced, the amount of misalignment of the positive electrode body 5b as a whole of the battery 1 is reduced. it can.

  Further, when the structure is formed by sequentially folding from the end portions of the positive and negative electrode main bodies in the form of a daisy chain, positional deviations are sequentially accumulated and increased from the start end side to the end side of the overlapping 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. In this embodiment, this problem can be solved.

  By the way, in the structure of the first embodiment, 12 positive electrode bodies 5b and 12 negative electrode bodies 3b are provided, and the present invention is applied to an electrochemical cell having a 24-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.

Second Embodiment
FIGS. 9-11 shows the negative electrode 53 and the positive electrode structure 54 for comprising the laminated body applied to the battery of 2nd Embodiment.
The negative electrode 53 and the positive electrode structure 54 of the second embodiment are both formed in an L shape in plan view in the developed state. The structure of the negative electrode 3 of the first embodiment is the same as that of the negative electrode 3 of the first embodiment in that the negative electrode 53 is formed by connecting the electrode connection portion 53a and the negative electrode main body 53b in a daisy chain. In addition, the negative electrode 53 is equivalent to the structure of the negative electrode 3 in the structure including the current collector layer and the active material layer. The negative electrode 3 of the first embodiment and the negative electrode 53 of the second embodiment are different only in a plan view structure.

  About the positive electrode structure 54, it is the structure equivalent to the positive electrode structure 4 of 1st Embodiment about the point which has formed the electrode connection part 55a and the positive electrode main body 55b in the shape of a daisy chain. In addition, regarding the structure including the current collector layer and the positive electrode active material layer, the positive electrode structure 54 has the same structure as the positive electrode structure 4 of the first embodiment. The structure in which the electrode connecting portion 55a and the positive electrode main body 55b are covered with the separator 56 is also equivalent to the structure of the first embodiment. That is, the structure is the same in the structure in which the electrode connecting portion 55 a is covered with the electrode connecting portion 56 a of the separator 56 and the positive electrode main body 55 b is covered with the protruding portion 56 b of the separator 56, and the outer shape of the protruding portion 56 b is the same as that of the negative electrode main body 53 b of the negative electrode 53. The same applies to the outer shape. The positive electrode structure 4 of the first embodiment and the positive electrode structure 54 of the second embodiment are different only in plan view.

  In the example shown in FIG. 9, as in the case of FIG. 7 showing the first embodiment, the outer shape of the protruding portion 56 b of the separator 56 provided in the positive electrode structure 54 and the negative electrode main body 53 b formed on the negative electrode 53. Although the outer shape is essentially the same, the outer shape of the overhanging portion 56b is drawn slightly smaller than the outer shape of the negative electrode main body 53b in FIG.

In the structure of the second embodiment, as shown in FIG. 10, a positive electrode body 55b (exactly located on the corner of the positive electrode structure 54 on the negative electrode body 53b positioned on the corner of the L-shaped negative electrode structure 53). Are arranged so that the whole is in a cross shape. In the overlapping state shown in FIG. 10, the overlapping portion of the negative electrode main body 53b and the positive electrode main body 55b (exactly the protruding portion 56b) becomes the reference overlapping portion b.
If the reference overlapping portion b is formed as shown in FIG. 10, the six positive electrode bodies 55b (exactly projecting portions 56b) located on the right side of the reference overlapping portion b and the upper side of the reference overlapping portion b are formed. As shown in (1) to (4) of FIG. 10, the five overhang portions 56b are sequentially folded.

That is, as shown in FIG. 10 (1), the positive electrode main body 55b (exactly, the protruding portion 56b) is folded back to the back side of the negative electrode main body 53b, and the negative electrode body 53b is folded back to the back side thereof as shown in (2). 3) As shown in (4), the operation of turning back the positive electrode main body 55b (exactly the projecting portion 56b) and the negative electrode main body 53b is repeated alternately.
By this zigzag folding, the six positive electrode main bodies 55b positioned on the right side of the reference overlapping portion b and the five overhanging portions 56b positioned on the upper side of the reference overlapping portion b can be alternately folded.
For reference, FIG. 11 shows a state where the two positive electrode main bodies 55b located on the right side of the reference overlapping portion b and the two overhang portions 56b positioned on the upper side of the reference overlapping portion b are folded and overlapped. Is shown.

After the above-described spell folding is completed, the six negative electrode main bodies 53b located on the left side of the reference overlapping portion b shown in FIG. 10 and the five positive electrode main bodies 55b located below the reference overlapping portion b (more precisely, If the overhang portions 56b) are alternately folded to the front side of the sheet of FIG. 10, the remaining negative electrode body 53b and the positive electrode body 55b can be folded.
In the zigzag folding structure described based on FIG. 10, the negative electrode main body 53b and the positive electrode main body 55b are zigzag folded on the front surface side (one side) and the back surface side (other side) of the reference overlapping portion b, respectively.

In the present embodiment, the laminated body as a whole has a 24-layer structure including the positive electrode main body 55b and the negative electrode main body 53b. However, when the front surface side (one side) and the back surface side (other side) of the reference overlapping portion b are individually viewed, folding of the six positive electrode main bodies 55b via the electrode connecting portions 55a and the electrode connecting portions 53a are A zigzag folding structure is formed by folding the six negative electrode bodies 55b interposed therebetween.
For this reason, since the accumulation of misalignment due to the folding of the six positive electrode main bodies 55b is sufficient, the misalignment of the positive electrode main body 55b is reduced as in the structure of the first embodiment. This situation is the same on the front surface side (one side) and the back surface side (other side) of the reference overlapping portion b.
Therefore, the same effects as the structure of the first embodiment can be obtained in the structure of the second embodiment. That is, the amount of displacement of the positive electrode main body 55b can be suppressed.

  In the battery structure of the first embodiment, since the reference overlapping portions a and a are overlapped with each other, a part of the overlapping structure is the same. Although it is disadvantageous in terms of the aspect, in the structure of the second embodiment, since the positive electrode main body 55b and the negative electrode main body 53b can be formed into a completely alternate laminated structure, the structure of the battery is more preferable.

<Third Embodiment>
FIGS. 12-14 shows the negative electrode 63 and the positive electrode structure 64 for comprising the laminated body applied to the battery of 3rd Embodiment.
The negative electrode 63 and the positive electrode structure 64 of the third embodiment are both formed in a band shape and a daisy chain shape in the developed state. The structure of the negative electrode 3 of the first embodiment is the same as that of the negative electrode 3 of the first embodiment in that the negative electrode 63 is formed by connecting the electrode connecting portion 63a and the negative electrode main body 63b in a daisy chain. In addition, the negative electrode 63 has the same structure as that of the negative electrode 3 in the structure including the current collector layer and the active material layer.

  About the positive electrode structure 64, it is the structure equivalent to the positive electrode structure 4 of 1st Embodiment about the point which has formed the electrode connection part 65a and the positive electrode main body 65b in the shape of a daisy chain. In addition, regarding the structure including the current collector layer and the positive electrode active material layer, the positive electrode structure 64 has the same structure as the positive electrode structure 4 of the first embodiment. Further, the structure in which the electrode connecting portion 65a and the positive electrode main body 65b are covered with the separator 66 is also equivalent to the structure of the first embodiment. That is, the structure in which the electrode connecting portion 65a is covered with the electrode connecting portion 66a of the separator 66 and the positive electrode main body 65b is covered with the overhanging portion 66b of the separator 66 is the same, and the outer shape of the overhanging portion 66b is the same as the outer shape of the negative electrode main body 63b. It is equivalent.

  In the example shown in FIG. 12, as in the case of FIG. 7 showing the first embodiment, the outer shape of the overhanging portion 66b of the separator 66 provided in the positive electrode structure 64 and the negative electrode body 63b formed in the negative electrode 63 are shown. The outer shape is essentially the same shape, but in FIG. 12, the outer shape of the overhanging portion 66b is drawn slightly smaller than the outer shape of the negative electrode main body 63b in order to easily distinguish the two electrodes.

  In the structure of the third embodiment, as shown in FIG. 13, along the length direction of the positive electrode structure 64 on the negative electrode body 63 b at the seventh position from the left side along the length direction of the negative electrode structure 63. The positive electrode main body 65b (exactly, the overhanging portion 66b) at the sixth position is overlapped and arranged so as to have a cross shape as a whole. In the overlapping state shown in FIG. 13, the overlapping portion of the negative electrode main body 63b and the positive electrode main body 65b (exactly, the protruding portion 66b) becomes the reference overlapping portion c.

If the reference overlapping portion c is formed as shown in FIG. 10, the five positive electrode main bodies 65b (exactly, the overhang portions 66b) located on the right side of the reference overlapping portion c and the reference overlapping portion c are located above. As shown in (1) to (4) of FIG. 13, the five overhang portions 56b that are positioned are sequentially folded.
That is, as shown in FIG. 13 (1), the positive electrode main body 65b (exactly, the protruding portion 66b) is folded back to the back side of the negative electrode main body 63b, and the negative electrode body 63b is folded back to the back side thereof as shown in (2). 3) As shown in (4), the operation of folding back the positive electrode main body 65b (exactly, the protruding portion 66b) and the negative electrode main body 63b is repeated alternately.

By this zigzag folding, the five positive electrode main bodies 65b positioned on the right side of the reference overlapping portion c and the five overhanging portions 63b positioned on the upper side of the reference overlapping portion b can be alternately folded.
For reference, FIG. 14 shows a state in which the two positive electrode bodies 65b positioned on the right side of the reference overlapping portion c and the two overhanging portions 66b positioned on the upper side of the reference overlapping portion c are folded and overlapped. Is shown.

After the above-described spell folding is completed, six positive electrode main bodies 65b (exactly projecting portions 66b) located on the left side of the reference overlapping portion c shown in FIG. 14 and six pieces positioned below the reference overlapping portion c. If the negative electrode bodies 63b are alternately folded into the front side of the sheet of FIG. 14, the remaining negative electrode bodies 63b and the positive electrode bodies 65b can be folded.
In the zigzag folding structure described based on FIG. 14, the negative electrode main body 63b and the positive electrode main body 65b are zigzag folded on the front surface side (one side) and the back surface side (other side) of the reference overlapping portion c, respectively.

In the present embodiment, the laminated body as a whole has a 24-layer structure including the positive electrode main body 65b and the negative electrode main body 63b. However, when the front surface side (one side) and the back surface side (other side) of the reference overlapping portion c are individually viewed, folding of the six positive electrode main bodies 65b via the electrode connecting portions 65a and the electrode connecting portions 63a are performed. A zigzag folding structure is formed by folding the six negative electrode main bodies 65b.
For this reason, since the accumulation of misalignment due to the folding of the six positive electrode main bodies 65b is sufficient, the misalignment of the positive electrode main body 65b is reduced as in the structure of the first embodiment. This situation is the same on the front surface side (one side) and the back surface side (other side) of the reference overlapping portion b.
Therefore, the same effects as the structure of the first embodiment can be obtained in the structure of the third embodiment. That is, the amount of displacement of the positive electrode main body 65b can be suppressed.

  In the battery structure of the first embodiment, since the reference overlapping portions a and a are overlapped with each other, a part of the overlapping structure is the same. Although it is disadvantageous in terms of the aspect, in the structure of the third embodiment, since the positive electrode main body 65b and the negative electrode main body 63b can be made into a completely alternate laminated structure, the structure of the battery is more preferable.

<Fourth embodiment>
FIG. 15 shows a negative electrode 73 and a positive electrode structure 4 for constituting a laminate applied to the battery of the fourth embodiment.
The negative electrode 73 and the positive electrode structure 4 of the fourth embodiment are both formed in a band shape and a daisy chain shape in the developed state. The structure of the negative electrode 3 of the first embodiment is the same as that of the negative electrode 3 of the first embodiment in that the negative electrode 73 is formed by connecting the electrode connecting portion 73a and the negative electrode main body 73b in a daisy chain. In addition, the negative electrode 73 is equivalent to the structure of the negative electrode 3 in the structure including the current collector layer and the active material layer.

In this example, as shown in FIG. 15, the strip-like positive electrode structure 4 is horizontally disposed with the positive electrode terminal 31 on the left side, and an inverted U-shaped negative electrode 73 is superimposed on the positive electrode structure 4.
In this example, the positive electrode structure 4 includes 12 positive electrode main bodies 5b connected in a row in a row, and a positive electrode terminal 31 is formed on the left end side. The negative electrode 73 is provided with two rows of six rows of negative electrode bodies 73b connected in a row and connected in an inverted U shape. The negative electrode body 73b on one end side of the first row of the negative electrode 73 is connected to the negative electrode body 73b on one end side of the second row so that the negative electrode 73 is formed in an inverted U-shape and one end side of the first row. The negative electrode terminal 21 is formed on the negative electrode main body 73b.
Further, the outer shape of the overhanging portion 6b of the separator 6 provided in the positive electrode structure 4 and the outer shape of the negative electrode main body 73b formed in the negative electrode 73 are essentially the same shape, but in FIG. In order to facilitate, the outer shape of the overhanging portion 6b is drawn slightly smaller than the outer shape of the negative electrode main body 73b.

  As shown in FIG. 15, the first row in the first row is placed on the sixth positive electrode main body 5b from the left end side (the side on which the positive electrode terminal 31 is formed) (more precisely, on the overhanging portion 6b of the separator 6). The negative electrode main body 73b is overlaid, and the negative electrode main body 73b on the one end side of the second row is overlaid on the seventh positive electrode main body 5b (more precisely, on the overhanging portion 6b of the separator 6). In other words, the two negative electrode main bodies 73b on one end side of the inverted U-shaped negative electrode 73 are overlapped on the central part (middle part) of the positive electrode structure 4 connected in a row of rows in a T-shape. The overlapped portion is set as a reference overlapping portion d.

  If the reference overlapping portion d is configured, the positive electrode main body 5b on the side where the positive electrode terminal 31 is formed (exactly, the protruding portion 6b of the separator 6) and the negative electrode main body 73b in the first row where the negative electrode terminal 21 is formed. Fold them in order. When these spell foldings are completed, the entire spelling folding structure can be realized by sequentially folding the remaining positive electrode body 5b (exactly, the protruding portion 6b of the separator 6) and the second row of negative electrode bodies 73b.

  In the configuration of the fourth embodiment, the entire laminate has a 24-layer structure including the positive electrode main body 5b and the negative electrode main body 73b. However, when the front surface side (one side) and the back surface side (other side) of the reference overlapping portion d are individually viewed, folding of the six positive electrode main bodies 5b via the electrode connection portions 5a and the electrode connection portions 73a are performed. A zigzag folding structure is formed by folding the six negative electrode bodies 5b interposed therebetween.

For this reason, since the accumulation of misalignment due to the folding of the six positive electrode bodies 5b is sufficient, the misalignment of the positive electrode body 5b is reduced as in the structure of the first embodiment. This situation is the same on the front surface side (one side) and the back surface side (the other side) of the reference overlapping portion d.
Therefore, the same effects as the structure of the first embodiment can be obtained in the structure of the fourth embodiment. That is, the amount of displacement of the positive electrode body 5b can be suppressed.

As described above, the shape of the daisy chain structure of the positive electrode body and the shape of the daisy chain structure of the negative electrode body may be any shape as long as they can be folded together.
Regarding the negative electrode main body 3b and the positive electrode main body 5b described so far, the electrode structure in which the electrodes are arranged in a straight line, a U shape, or an L shape via the electrode connecting portions 3a, 5a has been described. However, the negative electrode 3 and the positive electrode 5 are not necessarily limited to these shapes, and may be folded in a zigzag shape even if they are connected in a bent shape, a curved shape, etc. Or the shape of a negative electrode is not ask | required.

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. 16, 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 coating 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, 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, and an electrode terminal connecting step Includes S5.

  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).

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 step S2), 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. 6, the positive electrode 5 is covered with the first separator 41 and the second separator 42 constituting the separator 6, and these are heat-welded and integrated (electrode coating step S <b> 2). . 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. 6). 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 and the second separator 42 and the positive electrode 5 are thermally fused to obtain a positive electrode structure sheet. And the positive electrode structure sheet | seat is cut out in the strip | belt shape mentioned above with the slitter etc., and the positive electrode structure 4 shown in FIG. 5 is obtained. 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 overlap each other at the reference overlapping portion a as shown in FIG. 7 (electrode combination step: S3). The laminated body 2 is obtained by folding the reference overlapping portion a at the last (one side) and the left side (the other side), and finally folding back the reference overlapping portion a (zipper folding step: S4).

Since the negative electrode terminal 21 and the positive electrode terminal 31 protrude from the side of the laminate 2, after impregnating the laminate 2 with an electrolyte solution (not shown), the laminate 2 impregnated with the electrolyte solution is placed in the exterior body 10. The negative electrode terminal 21 is electrically connected to the negative electrode can body 12 side, and the positive electrode terminal 31 is electrically connected to the positive electrode can body 11 side (electrode terminal connection step: S5).
Subsequently, the battery 1 is completed by enclosing the laminate 2 in the outer package 10.

  If it is the battery 1 manufactured in this way, the battery 1 which has the above-mentioned outstanding effect by the zigzag folding structure on the one side and the other side via the reference | standard overlap part a can be obtained.

  a, b, c, d: reference overlapping part, 1 ... battery, 2 ... laminate, 3 ... negative electrode, 3a ... electrode connection part, 3b ... negative electrode body (overhanging 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 can body, 12 ... negative electrode can body, DESCRIPTION OF SYMBOLS 13 ... Gasket, 20 ... 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 ... first separator, 42 ... second separator, 53, 63 ... negative electrode, 53a, 63a ... electrode connection part, 53b, 63b ... negative electrode body, 54, 64 ... positive electrode structure, 54a, 64a ... Electrode connecting portion, 54b, 64b ... positive electrode body, 73 ... negative electrode, 73a ... electric Connecting portion, 74b ... anode body, S1 ... electrode processing step, S2 ... electrode coating step, S3 ... electrode combination step, S4 ... zigzag step, S5 ... electrode terminal connecting step.

Claims (14)

A plurality of positive electrode bodies arranged side by side, and a daisy chain-like positive electrode having an electrode connection part that connects two adjacent positive electrode bodies;
A plurality of negative electrode bodies arranged side by side, and a daisy chain-like negative electrode having an electrode connection part that connects two adjacent negative electrode bodies,
Comprising a separator disposed between the positive electrode and the negative electrode;
Either one or both of the daisy chain-like positive electrode body and the rosary string-like negative electrode body are a negative electrode or a positive electrode connected to either an L shape or a U shape,
A reference overlapping portion is configured by superimposing one or two negative electrodes of the interlaced intermediate portion on one or two of the positive electrodes in the intermediate portion of the beaded connection via the separator. The bead-connected positive electrode and the bead-connected negative electrode are alternately stacked in a folded manner through the separator on one side, and the bead-connected positive electrode and the bead-connected negative electrode on the other side. An electrochemical cell characterized in that is alternately stacked in a folded manner through the separator. The positive electrode is covered with a rosary separator having a protruding portion that covers the front and back surfaces and the peripheral surface of the positive electrode body of the positive electrode, and a connection portion that covers the front and back surfaces and the peripheral surface of the electrode connection portion,
The outer peripheral contour of the protruding portion of the separator and the outer peripheral contour of the negative electrode body of the negative electrode are aligned in the zigzag folded state,
2. 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 overlapping portion of the positive electrode and the negative electrode. Electrochemical cell. A plurality of positive electrode bodies arranged side by side, and a daisy chain-like positive electrode having an electrode connection part that connects two adjacent positive electrode bodies;
A plurality of negative electrode bodies arranged side by side, and a daisy chain-like negative electrode having an electrode connection part that connects two adjacent negative electrode bodies,
Comprising a separator disposed between the positive electrode and the negative electrode;
The lengths of the plurality of electrode connection portions in the positive electrode are the same, the lengths of the plurality of electrode connection portions in the negative electrode are the same,
A reference overlapping portion is configured by superimposing one or two negative electrodes of the interlaced intermediate portion on one or two of the positive electrodes in the intermediate portion of the beaded connection via the separator. The bead-connected positive electrode and the bead-connected negative electrode are alternately stacked in a folded manner through the separator on one side, and the bead-connected positive electrode and the bead-connected negative electrode on the other side. Are alternately stacked in a zigzag manner through the separator,
The outer peripheral contour of the positive electrode main body viewed along the overlapping direction is displaced for each overlapping layer, and the outer peripheral contour of the positive electrode main body is inside the outer peripheral contour of the negative electrode main body in the layer having the largest amount of positional displacement. An electrochemical cell characterized by being arranged. Based on the reference overlapping portion,
In the superposition of the positive electrode and the negative electrode on one side, 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 from the start end side of the superposition to the terminal end side is Enlarged,
In the superposition of the positive electrode and the negative electrode on the other side, 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 from the start end side of the superposition to the terminal end side is The electrochemical cell according to claim 3, wherein the electrochemical cell is enlarged. A plurality of positive electrode bodies arranged side by side, and a daisy chain-like positive electrode having an electrode connection part that connects two adjacent positive electrode bodies;
A plurality of negative electrode bodies arranged side by side, and a daisy chain-like negative electrode having an electrode connection part that connects two adjacent negative electrode bodies,
Comprising a separator disposed between the positive electrode and the negative electrode;
A reference overlapping portion is configured by superimposing one or two negative electrodes of the interlaced intermediate portion on one or two of the positive electrodes in the intermediate portion of the beaded connection via the separator. The bead-connected positive electrode and the bead-connected negative electrode are alternately stacked in a folded manner through the separator on one side, and the bead-connected positive electrode and the bead-connected negative electrode on the other side. Are alternately stacked in a zigzag manner through the separator,
Based on the reference overlapping portion,
In the superposition of the positive electrode and the negative electrode on one side, 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 from the start end side of the superposition to the terminal end side is Enlarged,
In the superposition of the positive electrode and the negative electrode on the other side, 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 from the start end side of the superposition to the terminal end side is An electrochemical cell characterized by being enlarged.   6. The outer peripheral contour of the positive electrode main body is disposed inside the outer peripheral contour of the negative electrode body viewed along the overlapping direction in the overlapping portion of the positive electrode and the negative electrode. Electrochemical cell.   Either one or both of the bead-connected positive electrode body and the bead-connected negative electrode body are a negative electrode or a positive electrode connected in a linear shape, an L shape, or a U shape. The electrochemical cell according to any one of claims 3 to 6.   8. The connection electrode terminal according to claim 1, wherein a connection electrode terminal is led out to one or both of a zigzag folded portion toward one side and a zigzag folded portion toward the other side with respect to the reference overlapping portion. An electrochemical cell according to claim 1. A plurality of positive electrode bodies arranged side by side and a daisy chain-like positive electrode having an electrode connection part for connecting two adjacent positive electrode bodies;
Using a plurality of negative electrode bodies arranged side by side and a negative electrode in the form of a daisy chain having an electrode connection part for connecting two adjacent negative electrode bodies,
The daisy-chain-like middle portion one or two of one or two negative electrode of the beaded-like intermediate portion to the positive electrode superimposed over the separators of the constructed reference overlapping portions, superimposed the reference portion , The bead-connected positive electrode and the bead-connected negative electrode are alternately stacked in a folded manner through the separator, and the bead-connected positive electrode and the bead-connected negative electrode are arranged on the other side. A method for producing an electrochemical cell, comprising alternately laminating the separators alternately through the separators.   10. 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 overlapping portion of the positive electrode and the negative electrode. Electrochemical cell 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,
Based on the reference overlapping portion,
In the superposition to one side, the outer peripheral contour of the positive electrode body in the layer with the largest amount of misalignment is positioned so that the outer peripheral contour of the positive electrode body viewed along the superposition direction is displaced for each overlapping layer. Superimposed so as to enter the outer periphery of the negative electrode body,
In the superposition to the other side, the outer peripheral contour of the positive electrode body in the layer with the largest amount of misalignment is positioned so that the outer peripheral contour of the positive electrode body viewed along the superposition direction is displaced for each overlapping layer. The method for producing an electrochemical cell according to claim 9, wherein superposition is performed so as to be inside the outer peripheral contour of the negative electrode main body. Based on the reference overlapping portion,
In the superposition of the positive electrode and the negative electrode on one side, 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 from the start end side of the superposition to the terminal end side is Overlapping to be larger,
In the superposition of the positive electrode and the negative electrode on the other side, 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 from the start end side of the superposition to the terminal end side is The method for producing an electrochemical cell according to claim 9, wherein the layers are overlapped so as to be large.  13. The connection electrode terminal is led out to one or both of a zigzag folded portion to one side and a zigzag folded portion to the other side with respect to the reference overlapping portion. The method for producing an electrochemical cell according to one item.   Either one or both of the bead-connected positive electrode body and the bead-connected negative electrode body are a negative electrode or a positive electrode connected in a linear shape, an L shape, or a U shape. The manufacturing method of the electrochemical cell as described in any one of Claims 9-13.

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