JP6274461B2 - 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, the charging current, and the discharging current. As a method for producing an electrochemical cell, there is known a method 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 electrolytic solution. For example, a strip-shaped electrode and a strip-shaped separator are wound and accommodated in a cylindrical or coin-shaped case, or deformed into a flat shape and then accommodated in a laminate film.
In recent years, a configuration in which a band-shaped electrode and a band-shaped separator are folded together in response to the demand for thinner wearable devices has been studied. For example, Patent Document 1 proposes a technique in which a strip-shaped cathode is accommodated in a separator bag body to form a strip-shaped cathode structure, and the strip-shaped cathode structure and the strip-shaped anode are alternately folded in an orthogonal direction.

JP-A-2005-243455

  However, when the belt-like cathode structure and the belt-like anode are alternately folded in the orthogonal direction, the possibility that the positions of the cathode electrode body and the anode electrode body are shifted as the spelling is repeated increases. Therefore, the conventional electrochemical cell has room for improvement in suppressing the displacement of the position of the electrode body.

  The present invention has been made to solve the above-described problems, and provides an electrochemical cell and a method for manufacturing the electrochemical cell that can prevent the positions of the positive electrode main body and the negative electrode main body from shifting. With the goal.

The electrochemical cell according to one embodiment of the present invention includes a plurality of positive electrode bodies arranged in one direction and a positive electrode body connection portion that connects two adjacent positive electrode bodies, and a strip-like positive electrode, A strip-shaped negative electrode having a plurality of negative electrode bodies arranged side by side in one direction, and a negative electrode main body connecting portion connecting two adjacent negative electrode bodies, and between the positive electrode and the negative electrode The positive electrode and the negative electrode are arranged in a strip-like manner in which the positive electrode main body and the negative electrode main body are alternately overlapped in the one direction via the separator. A plurality of structure bodies integrated with the separator and arranged in one direction, and a structure body connection portion that connects two adjacent structure bodies; Have The outer shape of the positive electrode is smaller than the outer shape of the negative electrode, and the outer shape of the positive electrode structure is the same size as the outer shape of the negative electrode. The positive electrode structure and the negative electrode are overlapped so that the structure main body and the negative electrode main body alternately overlap in the one direction, and the outer shape of the structure main body is the outer shape of the negative electrode main body. It is the same size .

According to this configuration, movement of the positive electrode body and the negative electrode body is restricted by alternately overlapping the positive electrode body and the negative electrode body in one direction. In addition, since the positive electrode and the negative electrode are formed in a band-shaped overlapping body, it is easy to align the positive electrode body and the negative electrode body in the width direction of the overlapping body. Therefore, it can suppress that the position of a positive electrode main body and a negative electrode main body shifts | deviates. By the way, when the two strip electrodes are alternately folded in the orthogonal direction, it is difficult to align the two strip electrodes in the zigzag folding process, a complicated mechanism is required, and the cycle time may be increased. On the other hand, according to this configuration, it is only necessary to squeeze one band-shaped superposed body, and therefore, alignment at the time of folding in the zigzag fold process is easy, no complicated mechanism is required, and cycle time is shortened. You can also.
In addition, it is possible to more effectively suppress the displacement of the position of the positive electrode compared to the case where the positive electrode is separated from the separator. Therefore, it can suppress more effectively that a position of a positive electrode main part and a negative electrode main part shifts.
By the way, when the lithium ion secondary battery is charged, lithium ions are moving from the positive electrode toward the negative electrode. At this time, if the end of the negative electrode is present at the portion where the positive electrode is opposed, the lithium ions that have moved from the positive electrode are concentrated on the end of the negative electrode due to the edge effect. For this reason, lithium ions that are normally absorbed by the negative electrode active material are referred to as needle-like lithium metal (hereinafter “lithium dendrite”) at the end of the negative electrode.
) May be deposited. This lithium dendrite may penetrate the separator and short-circuit the negative electrode and the positive electrode. Moreover, there is a possibility that the battery capacity may be reduced by the loss of lithium dendrite and the disconnection of electrical connection from the negative electrode. As a result, the reliability of the battery may be reduced. Here, in the configuration in which the belt-like electrode (positive electrode) is accommodated in the separator bag body, it is necessary to position the separator electrode on the side of the separator bag body when the positive electrode and the negative electrode are overlapped. For this reason, if the positive electrode in the separator bag is displaced, there is a high possibility that the end of the negative electrode is present at the portion where the positive electrode is opposed during the superposition operation. If the outer shape of the negative electrode is smaller than the outer shape of the positive electrode, the end portion of the negative electrode exists at the portion where the positive electrode is opposed. On the other hand, according to this configuration, since the outer shape of the positive electrode is smaller than the outer shape of the negative electrode, it is possible to more reliably avoid the presence of the end portion of the negative electrode at the portion where the positive electrode is opposed. Therefore, the reliability of the battery can be further improved by avoiding a short circuit and a decrease in battery capacity.
In addition, since the positive electrode structure and the negative electrode are more easily aligned than the case where the outer shape of the positive electrode structure is different from that of the negative electrode, the positions of the positive electrode body and the negative electrode body are Deviation can be easily suppressed. In addition, it is possible to more reliably avoid the presence of the end portion of the negative electrode at the portion where the positive electrode is opposed. In addition, the folding of the positive electrode structure and the negative electrode is facilitated.

  Said electrochemical cell WHEREIN: The said positive electrode main body connection part and the said negative electrode main body connection part may have shifted | deviated to the mutually opposite direction in the width direction of the said laminated body.

  By the way, when a positive electrode main body connection part and a negative electrode main body connection part are arrange | positioned in the position which overlaps in the width direction of a laminated body, a positive electrode main body connection part and a negative electrode main body connection part may interfere. On the other hand, according to this configuration, it is possible to avoid the interference between the positive electrode main body connection portion and the negative electrode main body connection portion, so that the positions of the positive electrode main body and the negative electrode main body are shifted due to the interference. Can be suppressed. In addition, the positive electrode main body connection portion and the negative electrode main body connection portion can be avoided from being entangled in the zigzag folding process.

In the electrochemical cell, the outer shape of the structure body may be a circular shape having the same size as the outer shape of the negative electrode body.

  According to this configuration, the structure main body and the negative electrode main body are overlapped to form a coin, which is preferable when the belt-shaped stacked body is folded and accommodated in a coin-shaped case.

In the electrochemical cell, a structure-side notch is formed on one side in the width direction of the structure body connecting portion, and a structure-side notch non-forming portion is formed on the other side in the width direction of the structure body connecting portion. A negative electrode side notch is formed on one side in the width direction of the negative electrode main body connecting portion, and a negative electrode side notch non-forming portion is provided on the other side in the width direction of the negative electrode main body connecting portion, The stacked body has the negative electrode side notch non-formed portion in the structure side cutout so that the structure main body and the negative electrode main body alternately overlap in the one direction, and the negative electrode side cutout The structure side notch non-formation part may enter and may be comprised.

  According to this structure, it can suppress more effectively that the position of a positive electrode shifts compared with the case where the positive electrode is separated from the separator. In addition, the negative electrode side notch non-formed part enters the structure side notch, and the structure side notch non-formed part enters the negative electrode side notch, so that the structure body connection part in the width direction of the stacked body And the movement of the negative electrode main body connecting portion is restricted. Therefore, it can suppress more effectively that a position of a positive electrode main part and a negative electrode main part shifts.

  In the above electrochemical cell, the stacked body may be a stacked body folded in a zigzag shape.

  According to this configuration, since the superposed body can be accommodated in the case in the state of being a laminated body, the electrochemical cell can be made compact.

The method for producing an electrochemical cell according to one aspect of the present invention includes a plurality of positive electrode bodies arranged side by side in one direction, and a positive electrode body connection portion that connects two adjacent positive electrode bodies. A strip-shaped negative electrode having an electrode, a plurality of negative electrode bodies arranged side by side in the one direction, and a negative electrode main body connecting portion connecting two adjacent negative electrode bodies; the positive electrode and the negative electrode; A separator disposed between the positive electrode body and the negative electrode electrode, and the positive electrode body and the negative electrode body are disposed in the one direction through the separator. the superposed so as to overlap alternately viewing including the overlapping body forming step of forming a strip overlay body, before the superimposition body forming step, the positive electrode integral with the separator, in the one direction common A positive electrode structure forming step of forming a positive electrode structure having a band-like positive electrode structure, and a plurality of structure main bodies arranged in the structure and a structure main body connecting portion connecting two adjacent structure main bodies. Before the body forming step, the outer shape of the positive electrode is made smaller than the outer shape of the negative electrode, and in the positive electrode structure forming step, the outer shape of the positive electrode structure is made the same size as the outer shape of the negative electrode, In the superposed body forming step, the positive electrode structure and the negative electrode are superposed such that the structure main body and the negative electrode main body alternately overlap in the one direction, and in the positive electrode structure forming step, The outer shape of the structure body is the same as the outer shape of the negative electrode body .

According to this method, the positive electrode main body and the negative electrode main body are alternately overlapped in one direction, whereby movement between the positive electrode main body and the negative electrode main body is restricted. In addition, by forming a band-shaped overlapping body with the positive electrode and the negative electrode, it is easy to align the positive electrode body and the negative electrode body in the width direction of the overlapping body. Therefore, it can suppress that the position of a positive electrode main body and a negative electrode main body shifts | deviates. By the way, when the two strip electrodes are alternately folded in the orthogonal direction, it is difficult to align the two strip electrodes in the zigzag folding process, a complicated mechanism is required, and the cycle time may be increased. On the other hand, according to this method, since one belt-like superposed body only needs to be folded in a zigzag manner, the alignment at the time of folding in the zigzag folding process is easy, a complicated mechanism is not required, and the cycle time is shortened. You can also
In addition, it is possible to more effectively suppress the displacement of the position of the positive electrode compared to the case where the positive electrode is separated from the separator. Therefore, it can suppress more effectively that a position of a positive electrode main part and a negative electrode main part shifts.
In addition, since the outer shape of the positive electrode is smaller than the outer shape of the negative electrode, it can be more reliably avoided that the end portion of the negative electrode exists in the portion where the positive electrode is opposed. Therefore, the reliability of the battery can be further improved by avoiding a short circuit and a decrease in battery capacity.
In addition, compared with the case where the outer shape of the positive electrode structure is different from the outer shape of the negative electrode, it is easier to align the positive electrode structure and the negative electrode, so the positions of the positive electrode body and the negative electrode body are misaligned. This can be easily suppressed. In addition, it is possible to more reliably avoid the presence of the end portion of the negative electrode at the portion where the positive electrode is opposed. In addition, the folding of the positive electrode structure and the negative electrode is facilitated.

  In the electrochemical cell manufacturing method, in the overlap body forming step, the positive electrode main body connection portion and the negative electrode main body connection portion may be shifted in opposite directions in the width direction of the overlap body.

  According to this method, since it is possible to avoid the interference between the positive electrode main body connection portion and the negative electrode main body connection portion, it is possible to suppress the displacement of the positions of the positive electrode main body and the negative electrode main body due to the interference. it can. In addition, the positive electrode main body connection portion and the negative electrode main body connection portion can be avoided from being entangled in the zigzag folding process.

  In the electrochemical cell manufacturing method, in the positive electrode structure forming step, the positive electrode is covered with a resin-made first separator and a resin-made second separator that constitute the separator, The first separator and the second separator may be heat-sealed.

  According to this method, since the movement of the positive electrode is restricted by thermally fusing the first separator and the second separator together, the displacement of the positive electrode is more effectively suppressed. Can do. Therefore, it can avoid that the position of a positive electrode main body shifts | deviates due to the position shift of a positive electrode, and can suppress more effectively that the position of a positive electrode main body and a negative electrode main body shifts | deviates.

In the electrochemical cell manufacturing method, in the positive electrode structure forming step, the outer shape of the structure body may be a circular shape having the same size as the outer shape of the negative electrode body.

  According to this method, since the structure main body and the negative electrode main body can be overlapped to form a coin, it is preferable when the belt-shaped overlapped body is folded and accommodated in a coin-shaped case.

In the electrochemical cell manufacturing method described above, the structure-side notch is formed on one side in the width direction of the structure body connecting portion before the overlapping body forming step, and the width direction of the structure body connecting portion A structure-side notch non-forming portion is provided on the other side of the negative electrode body , and a negative electrode-side notch is formed on one side in the width direction of the negative electrode main body connection portion , and a negative electrode on the other side in the width direction of the negative electrode main body connection portion A side notch non-forming portion is provided, and in the overlapping body forming step, the negative electrode side notch is not formed in the structure side notch so that the structure main body and the negative electrode main body alternately overlap in the one direction. The structure side notch non-forming part may be inserted into the negative electrode side notch.

  According to this method, it is possible to more effectively suppress the displacement of the position of the positive electrode compared to the case where the positive electrode is separated from the separator. In addition, the structure main body connection portion in the width direction of the stacked body is formed by inserting the negative electrode side notch non-forming portion into the structure side notch and inserting the structure side notch non forming portion into the negative electrode notch. And the movement of the negative electrode main body connecting portion is restricted. Therefore, it can suppress more effectively that a position of a positive electrode main part and a negative electrode main part shifts.

  In the above electrochemical cell manufacturing method, after the overlapping body forming step, the overlapping body may be folded into a zigzag shape to form a laminated body.

  According to this method, since the stacked body can be accommodated in the case in a stacked state, the electrochemical cell can be made compact.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrochemical cell and electrochemical cell which can suppress that the position of a positive electrode main body and a negative electrode main body shifts can be provided.

It is a top view of the battery concerning a 1st embodiment. It is II-II sectional drawing of FIG. It is a perspective view of the layered product concerning a 1st embodiment. It is a top view which shows the expansion | deployment state of the laminated body which concerns on 1st Embodiment. 1 is a perspective view of a positive electrode structure according to a first embodiment. It is a top view which shows the expansion | deployment state of the positive electrode structure which concerns on 1st Embodiment. It is a top view which shows the expansion | deployment state of the negative electrode which concerns on 1st Embodiment. It is a flowchart of the manufacturing method of the battery which concerns on 1st Embodiment. It is process drawing which shows the manufacturing method of the battery which concerns on 1st Embodiment. FIG. 10 is a process diagram following FIG. 9. FIG. 11 is a process diagram following FIG. 10. FIG. 12 is a process diagram following FIG. 11. It is a top view which shows the expansion | deployment state of the laminated body which concerns on 2nd Embodiment. It is a top view which shows the expansion | deployment state of the positive electrode structure which concerns on 2nd Embodiment. It is a top view which shows the expansion | deployment state of the negative electrode which concerns on 2nd Embodiment. It is process drawing which shows the manufacturing method of the battery which concerns on 2nd Embodiment. It is a top view which shows the expansion | deployment state of the laminated body which concerns on 3rd Embodiment. It is a top view which shows the expansion | deployment state of the positive electrode structure which concerns on 3rd Embodiment. It is a top view which shows the expansion | deployment state of the negative electrode which concerns on 3rd Embodiment. It is process drawing which shows the manufacturing method of the battery which concerns on 3rd 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 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 laminated body 2 is obtained by folding a band-shaped superposed body 3 into a zigzag folded shape. In other words, the stacked body 2 includes a positive electrode structure 4 folded in a zigzag folded shape, and a negative electrode 7 folded in a zigzag folded shape so as to be stacked alternately with the positive electrode structure 4.

[Superposition]
The stacked body 3 has a strip shape. Specifically, in the developed state of the stacked body 3 shown in FIG. 4, the stacked body 3 has a strip shape in which the positive structure 4 and the negative electrode 7 are stacked so as to alternately overlap in one direction. The stacked body 3 is configured by stacking the positive electrode structure 4 and the negative electrode 7 so that the structure main body 4a and the negative electrode main body 7a are alternately overlapped in one direction. That is, referring to FIG. 4 and FIG. 6 together, the positive electrode 5 and the negative electrode 7 are band-like layers in which the positive electrode main body 5a and the negative electrode main body 7a are alternately overlapped in one direction with the separator 6 interposed therebetween. It is set as the superposition body 3 of these.

  Hereinafter, the direction orthogonal to the longitudinal direction of the stacked body 3 is referred to as “width direction of the stacked body 3”. Reference numeral 3L in the figure denotes an imaginary straight line that passes through the center in the width direction of the superposed body 3 and is parallel to the longitudinal direction of the superposed body 3 (hereinafter referred to as “superimposed body axis 3L”). It is.

  The structure main body connecting portion 4b and the negative electrode main body connecting portion 7b are shifted in opposite directions in the width direction of the stacked body 3. That is, in the unfolded state of the stacked body 3, the positive electrode main body connecting portion 5 b and the separator main body connecting portion 6 b and the negative electrode main body connecting portion 7 b are shifted in opposite directions in the width direction of the stacked body 3.

[Positive electrode structure]
As shown in FIG. 5, 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 7.

  The positive electrode structure 4 has a strip shape. Specifically, in the developed state of the positive electrode structure 4 shown in FIG. 6, the positive electrode structure 4 is adjacent to a plurality of (for example, eight in this embodiment) structure bodies 4 a arranged in one direction. And a structure body connection portion 4b for connecting the two structure bodies 4a.

  Hereinafter, the direction orthogonal to the longitudinal direction of the positive electrode structure 4 is referred to as the “width direction of the positive electrode structure 4”. Reference numeral 4L in the figure is an imaginary straight line (hereinafter referred to as “structure axis 4L”) that passes through the center in the width direction of the positive electrode structure 4 and is parallel to the longitudinal direction of the positive electrode structure 4 in the expanded state of the positive electrode structure 4. is there.

The structure body 4a protrudes outward from the structure body connection portion 4b in the width direction of the positive electrode structure 4. The structure body 4a has a circular shape in plan view. The outer shape of the structure body 4a has a circular shape that is substantially the same size as the outer shape of the negative electrode body 7a (see FIG. 7).
The structure body connecting portion 4 b is shifted to one side in the width direction of the positive electrode structure 4. That is, the structure main body connection portion 4b is disposed at a position avoiding the structure axis 4L in a plan view in the expanded state of the positive electrode structure 4.

[Positive electrode]
The positive electrode 5 has a strip shape. Specifically, in the developed state of the positive electrode structure 4 shown in FIG. 6, the positive electrode 5 includes a plurality of (for example, eight in the present embodiment) positive electrode bodies 5 a arranged side by side in one direction, And a positive electrode main body connecting portion 5b for connecting the positive electrode main body 5a.

  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”. Reference numeral 5 </ b> L in the drawing is a virtual straight line (hereinafter referred to as “positive electrode axis 5 </ b> L”) that passes through the center in the width direction of the positive electrode 5 and is parallel to the longitudinal direction of the positive electrode 5 in the expanded state of the positive electrode structure 4. The positive electrode axis 5L overlaps the structure axis 4L in plan view.

The positive electrode main body 5 a projects outward from the positive electrode main body connecting portion 5 b in the width direction of the positive electrode 5. The positive electrode main body 5a has a circular shape in plan view.
The positive electrode main body connecting portion 5 b is shifted to one side in the width direction of the positive electrode 5. That is, the positive electrode main body connection portion 5b is disposed at a position avoiding the positive electrode axis 5L in a plan view when the positive electrode structure 4 is expanded.

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

  3 and 5 together, the outer shape of the positive electrode 5 is smaller than the outer shape of the negative electrode 7. That is, the outer shapes of the positive electrode main body connecting portion 5 b and the positive electrode main body 5 a in the positive electrode 5 are smaller than the outer shapes of the negative electrode main body connecting portion 7 b and the negative electrode main body 7 a in the negative electrode 7.

  As shown in FIG. 2, the positive electrode 5 includes a strip-like 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. 5, an extension portion 31 of the positive electrode current collector 30 is formed at one end portion of the positive electrode 5. The extending portion 31 is a portion of the positive electrode current collector 30 that extends outward from the positive electrode body 5 a 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]
The separator 6 has a strip shape. Specifically, in the developed state of the positive electrode structure 4 shown in FIG. 6, the separator 6 includes a plurality (for example, eight in this embodiment) of separator bodies 6 a arranged in one direction and two adjacent separators. And a separator main body connection portion 6b for connecting the main body 6a. The separator 6 is disposed between the positive electrode 5 and the negative electrode 7.

  Hereinafter, a direction orthogonal to the longitudinal direction of the separator 6 is referred to as a “width direction of the separator 6”. 6L is a virtual straight line (hereinafter referred to as “separator axis 6L”) that passes through the center of the separator 6 in the width direction and is parallel to the longitudinal direction of the separator 6 in the expanded state of the positive electrode structure 4. The separator axis 6L overlaps the structure axis 4L in plan view.

The separator body 6a projects outward from the separator body connection portion 6b in the width direction of the separator 6. The separator body 6a has a circular shape in plan view.
The separator main body connection portion 6 b is shifted to one side in the width direction of the separator 6. That is, the separator main body connection portion 6b is disposed at a position avoiding the separator axis 6L in a plan view when the positive electrode structure 4 is expanded.

  3 and 5 together, the outer shapes of the separator main body 6a and the separator main body connecting portion 6b in the separator 6 are substantially the same as the negative electrode main body 7a and the negative electrode main body connecting portion 7b in the negative electrode 7.

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 the first separator 41 of the pair shown in FIG. 9 and the second separator 42 are integrated 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 shown in FIG. Is shown.

[Negative electrode]
The negative electrode 7 has a strip shape. Specifically, in the developed state of the negative electrode 7 shown in FIG. 7, a plurality (for example, eight in this embodiment) of negative electrode bodies 7a arranged in one direction are connected to two adjacent negative electrode bodies 7a. A negative electrode main body connection portion 7b.

  Hereinafter, the direction orthogonal to the longitudinal direction of the negative electrode 7 is referred to as the “width direction of the negative electrode 7”. Reference numeral 7L in the drawing is a virtual straight line (hereinafter referred to as “negative electrode axis 7L”) that passes through the center in the width direction of the negative electrode 7 and is parallel to the longitudinal direction of the negative electrode 7 in the developed state of the negative electrode 7.

The negative electrode main body 7 a protrudes outside the negative electrode main body connection portion 7 b in the width direction of the negative electrode 7. The negative electrode body 7a has a circular shape in plan view.
The negative electrode main body connecting portion 7 b is shifted to one side in the width direction of the negative electrode 7. That is, the negative electrode main body connection portion 7b is disposed at a position avoiding the negative electrode axis 7L in a plan view when the negative electrode 7 is deployed.

  As shown in FIG. 3, the negative electrode bodies 7 a are arranged substantially parallel to each other when the negative electrode 7 is in a folded state. The negative electrode main body connection portion 7 b is continuous with the edge of each negative electrode main body 7 a in the longitudinal direction of the negative electrode 7. That is, the negative electrode main body connecting portion 7b connects two adjacent negative electrode main bodies 7a in series.

  As shown in FIG. 2, the negative electrode 7 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. Although not shown, the negative electrode current collector 20 has a strip shape. As shown in FIG. 3, an extension portion 21 of the negative electrode current collector 20 is formed at one end portion of the negative electrode 7. The extending portion 21 is a portion of the negative electrode current collector 20 that extends outward from the negative electrode body 7 a in the longitudinal direction of the negative electrode 7.

  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.

[Exterior body]
Referring to FIGS. 1 and 2 together, the outer package 10 includes a positive electrode can body 11, a negative electrode can body 12, a gasket 13 that electrically insulates between the positive electrode can body 11 and the negative electrode can body 12, It has.
The positive electrode can body 11 and the negative electrode can body 12 have a bottomed cylindrical shape. The inner diameter of the positive electrode can body 11 is 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. Thereby, the laminated body 2 is sealed by the exterior body 10. 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 terminal. 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, the illustration of the extending portion 31 is partially omitted.

[Battery manufacturing method]
Next, an example of the manufacturing method of the battery 1 described above will be described.
As shown in FIG. 8, the manufacturing method of the battery 1 includes an electrode processing step S1 for processing the positive electrode 5 into a predetermined shape, an electrode covering step S2 for covering the positive electrode 5 with the separator 6, and the positive electrode 5 for the separator 6. A positive electrode structure forming step S3 for forming an integrated belt-like positive electrode structure 4, a superposed body forming step S4 for superposing the positive electrode structure 4 and the negative electrode 7 to form a belt-like superposed body 3, and a superposition A zigzag folding step S5 for folding the body 3 into a zigzag folded shape.

  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 7.
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 7.

  Next, as shown in FIG. 9, the positive electrode 5 is sandwiched and covered by the first separator 41 and the second separator 42 that constitute the separator 6 (electrode coating step S2). Hereinafter, what covered and covered the positive electrode 5 between the first separator 41 and the second separator 42 is referred to as a “positive electrode covering”. 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. 9). The outer shape of the first separator 41 and the second separator 42 only needs to be large enough to cover the positive electrode main body 5a and the positive electrode main body connecting portion 5b of the positive electrode 5 and expose the extending portion 31.

Next, the first separator 41 and second separator 42 to thermally fuse (positive electrode structure forming step S3). In the positive electrode structure forming step S <b> 3, the positive electrode 5 is used as the positive electrode structure 4 integrated with the separator 6.

For example, in the positive electrode structure forming step S <b> 3, an iron or the like is pressed against the positive electrode covering from the first separator 41 side or the second separator 42 side. That is, the positive electrode covering is heated while being compressed in the thickness direction. Thus, the thermally fusing the a first separator 41 made of resin and the second separator 42, and a binder of the first separator 41 and second separator 42 and the positive electrode 5 made of resin by thermal fusion A positive electrode structure sheet 4A shown in FIG. 10 is obtained.
Then, the positive electrode structure sheet 4A is cut out in the above-described band shape with a slitter or the like to obtain the positive electrode structure 4 shown in FIG.

  In the positive electrode structure forming step S3, a plurality of structure bodies 4a arranged side by side in one direction and a structure body connection portion 4b that connects two adjacent structure bodies 4a are formed. 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 7. Specifically, the outer shape of the structure body 4a is a circular shape having substantially the same size as the outer shape of the negative electrode body 7a.

  In the positive electrode structure forming step S3, the positive electrode covering body is cut out from the first separator 41 side or the second separator 42 side with a heat cutter or an ultrasonic cutter, or the positive electrode covering body is irradiated with a laser. The positive electrode structure 4 shown in FIG. 6 can also be obtained directly by the cutting method using heat. If it is the cutting method by the said heat | fever, since the cutting | disconnection part of the 1st separator 41 and the 2nd separator 42 can be heat-seal | fused simultaneously with the cutting-out of a positive electrode covering body, it is suitable at the point which aims at efficiency of work.

  Next, the positive electrode structure 4 and the negative electrode 7 are superposed to form a belt-like superposed body 3 (superposed body forming step S4).

  As shown in FIG. 11, in the overlap body forming step S <b> 4, the structure body connection portion 4 b (in other words, the positive electrode body connection portion 5 b) and the negative electrode body connection portion 7 b are opposite to each other in the width direction of the overlap body 3. Shift in the direction. Next, the positive electrode structure 4 and the negative electrode 7 are overlapped so that the structure main body 4a and the negative electrode main body 7a are alternately overlapped in one direction. That is, referring to FIG. 4 and FIG. 6 together, the positive electrode 5 and the negative electrode 7 are overlapped through the separator 6 so that the positive electrode main body 5a and the negative electrode main body 7a are alternately overlapped in one direction. The superposed body 3 is formed.

  Next, the superposed body 3 is folded into a spelled shape (zipper folding step S5). In FIG. 12, the bent portions of the superposed body 3 are indicated by reference numerals T1 to T7 (dashed lines). The bent portions T1, T3, T5, and T7 are portions that are valley-folded, and the bent portions T2, T4, and T6 are portions that are mountain-folded.

In the zigzag folding step S5, the connection portions (that is, the structure main body connection portion 4b and the negative electrode main body connection portion 7b) of the stacked body 3 are bent in the arrow direction V1 along the bent portion T1.
Next, the connecting portion of the superposed body 3 is bent in the arrow direction V2 (that is, the direction opposite to the arrow direction V1) along the bent portion T2.
Next, the connecting portion of the superposed body 3 is bent in the arrow direction V3 (that is, the direction opposite to the arrow direction V2) along the bent portion T3.
Next, the connecting portion of the stacked body 3 is bent along the bent portion T4 in the arrow direction V4 (that is, the direction opposite to the arrow direction V3).
Next, the connecting portion of the stacked body 3 is bent along the bent portion T5 in the arrow direction V5 (that is, the direction opposite to the arrow direction V4).
Next, the connecting portion of the superposed body 3 is bent in the arrow direction V6 (that is, the direction opposite to the arrow direction V5) along the bent portion T6.
Next, the connecting portion of the superposed body 3 is bent along the bent portion T7 in the arrow direction V7 (that is, the direction opposite to the arrow direction V6).
In this way, the connection portion of the stacked body 3 is bent so that the structure body 4a and the negative electrode body 7a alternately overlap in the stacking direction (the thickness direction of the stack 2). Thus, the above-mentioned laminated body 2 (refer FIG. 3) is obtained by spelling and folding.

  Then, after impregnating the laminate 2 with an electrolyte solution (not shown), the laminate 2 impregnated with the electrolyte solution is enclosed in the exterior body 10 to complete the battery 1 (see FIG. 2) of the present embodiment. .

  As described above, the battery 1 according to the present embodiment has a strip shape having a plurality of positive electrode main bodies 5a arranged in one direction and a positive electrode main body connecting portion 5b that connects two adjacent positive electrode main bodies 5a. A strip-like negative electrode 7 having a positive electrode 5, a plurality of negative electrode main bodies 7 a arranged side by side in the one direction, and a negative electrode main body connecting portion 7 b connecting two adjacent negative electrode main bodies 7 a, and a positive electrode 5 and the separator 6 disposed between the negative electrode 7 and the positive electrode 5 and the negative electrode 7 are alternately arranged in the one direction with the positive electrode body 5a and the negative electrode body 7a through the separator 6. It is set as the strip | belt-shaped superposition body 3 piled up so that it might overlap. Moreover, the manufacturing method of the battery 1 according to the present embodiment is a belt-like shape having a plurality of positive electrode main bodies 5a arranged in one direction and a positive electrode main body connecting portion 5b connecting two adjacent positive electrode main bodies 5a. A strip-like negative electrode 7 having a positive electrode 5, a plurality of negative electrode main bodies 7 a arranged side by side in the one direction, and a negative electrode main body connection portion 7 b connecting two adjacent negative electrode main bodies 7 a, and the positive electrode 5 And a separator 6 disposed between the positive electrode body 5a and the negative electrode body 7a. The positive electrode body 5a and the negative electrode body 7a are connected to each other via the separator 6. And a superposed body forming step S4 for superposing the belt-like superposed bodies 3 so as to overlap each other alternately in the one direction.

  According to this embodiment, the positive electrode main body 5a and the negative electrode main body 7a are alternately overlapped in one direction, so that the movement between the positive electrode main body 5a and the negative electrode main body 7a is restricted. In addition, since the positive electrode 5 and the negative electrode 7 are formed in a band-shaped superposed body 3, it is easy to align the positive electrode main body 5a and the negative electrode main body 7a in the width direction of the superposed body 3. Therefore, it can suppress that the position of the positive electrode main body 5a and the negative electrode main body 7a shifts | deviates. By the way, when the two strip electrodes are alternately folded in the orthogonal direction, it is difficult to align the two strip electrodes in the zigzag folding process, a complicated mechanism is required, and the cycle time may be increased. On the other hand, according to the present embodiment, one belt-like superposed body 3 has only to be folded in a zigzag manner, so that the alignment at the time of folding in the zigzag folding step S5 is easy, no complicated mechanism is required, and the cycle time Can be shortened.

  Further, in the present embodiment, the positive electrode main body connection portion 5b and the negative electrode main body connection portion 7b are shifted in opposite directions in the width direction of the stacked body 3.

  By the way, when the positive electrode main body connection portion 5b and the negative electrode main body connection portion 7b are arranged at positions where they overlap each other in the width direction of the stacked body 3, the positive electrode main body connection portion 5b and the negative electrode main body connection portion 7b may interfere with each other. There is. On the other hand, according to the present embodiment, it is possible to avoid interference between the positive electrode main body connection portion 5b and the negative electrode main body connection portion 7b, and therefore, the positive electrode main body 5a and the negative electrode main body 7a are caused by the interference. It is possible to suppress the displacement. In addition, the positive electrode main body connecting portion 5b and the negative electrode main body connecting portion 7b can be prevented from being entangled in the spelling step S5.

  In the present embodiment, the positive electrode 5 is a strip-like positive electrode structure 4 integrated with the separator 6.

  According to this embodiment, compared with the case where the positive electrode 5 is separated from the separator 6, it is possible to more effectively suppress the position of the positive electrode 5 from shifting. Therefore, it can suppress more effectively that the position of the positive electrode main body 5a and the negative electrode main body 7a shifts | deviates.

  In the present embodiment, the outer shape of the positive electrode 5 is smaller than the outer shape of the negative electrode 7.

By the way, when the lithium ion secondary battery is charged, lithium ions are moving from the positive electrode toward the negative electrode. At this time, if the end of the negative electrode is present at the portion where the positive electrode is opposed, the lithium ions that have moved from the positive electrode are concentrated on the end of the negative electrode due to the edge effect. Therefore, lithium ions that would otherwise be absorbed by the negative electrode active material may be deposited as lithium dendrites at the end of the negative electrode. This lithium dendrite may penetrate the separator and short-circuit the negative electrode and the positive electrode. Moreover, there is a possibility that the battery capacity may be reduced by the loss of lithium dendrite and the disconnection of electrical connection from the negative electrode. As a result, the reliability of the battery may be reduced. Here, in the configuration in which the belt-like electrode (positive electrode) is accommodated in the separator bag body, it is necessary to position the separator electrode on the side of the separator bag body when the positive electrode and the negative electrode are overlapped. For this reason, if the positive electrode in the separator bag is displaced, there is a high possibility that the end of the negative electrode is present at the portion where the positive electrode is opposed during the superposition operation. If the outer shape of the negative electrode is smaller than the outer shape of the positive electrode, the end portion of the negative electrode exists at the portion where the positive electrode is opposed.
On the other hand, according to the present embodiment, since the outer shape of the positive electrode 5 is smaller than the outer shape of the negative electrode 7, it is more reliably avoided that the end portion of the negative electrode 7 is present at the portion facing the positive electrode 5. can do. Therefore, it is possible to further improve the reliability of the battery 1 by avoiding a short circuit and a decrease in battery capacity.

  In the present embodiment, the outer shape of the positive electrode structure 4 is the same as the outer shape of the negative electrode 7.

  According to this embodiment, the positive electrode structure 4 and the negative electrode 7 can be easily aligned as compared with the case where the outer shape of the positive electrode structure 4 is different from the outer shape of the negative electrode 7. It is possible to easily prevent the positions of the main body 5a and the negative electrode main body 7a from shifting. In addition, it can be avoided more reliably that the end of the negative electrode 7 is present at the portion where the positive electrode 5 faces. In addition, the folding of the positive electrode structure 4 and the negative electrode 7 is facilitated.

  In the present embodiment, the positive electrode structure 4 includes a plurality of structure bodies 4a arranged side by side in the one direction, and a structure body connection portion 4b that connects two adjacent structure bodies 4a. The stacked body 3 is configured such that the positive electrode structure 4 and the negative electrode 7 are overlapped so that the structure body 4a and the negative electrode body 7a are alternately overlapped in the one direction, and the outer shape of the structure body 4a Has a circular shape having the same size as the outer shape of the negative electrode body 7a.

  According to the present embodiment, the structure main body 4a and the negative electrode main body 7a are overlapped to form a coin, which is preferable when the belt-shaped stacked body 3 is folded and accommodated in a coin-shaped case.

Moreover, in the manufacturing method of the battery 1 according to the present embodiment, the positive electrode 5 is sandwiched between the resin-made first separator 41 and the resin-made second separator 42 in the positive electrode structure forming step S3. in after covering, it is thermally fused with the first separator 41 and second separator 42.

According to this method, since the movement of the positive electrode 5 is restricted by forming integrally by thermal fusion bonding the first separator 41 and second separator 42, more effective that the position of the positive electrode 5 is displaced Can be suppressed. Therefore, it can avoid that the position of the positive electrode main body 5a shifts | deviates due to the position shift of the positive electrode 5, and it can suppress more effectively that the position of the positive electrode main body 5a and the negative electrode main body 7a shifts | deviates.

  In the present embodiment, the positive electrode main body connection portion 5b and the negative electrode main body connection portion 7b have been described with reference to an example in which they are shifted in opposite directions in the width direction of the stacked body 3. The connecting portion 5b and the negative electrode main body connecting portion 7b may be disposed at a position where they overlap in the width direction of the stacked body 3.

Second Embodiment
FIG. 13 is a plan view showing a developed state of the stacked body 203 according to the second embodiment, and corresponds to FIG.
The second embodiment is different from the first embodiment in that the structure body connecting portion 204b is inserted through the slit 207c. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

[Superposition]
As shown in FIG. 13, in the unfolded state of the superposed body 203, the superposed body 203 has the structure main body connecting portions 204b that have slits 207c so that the structure main body 204a and the negative electrode main body 207a are alternately overlapped in one direction. It is configured to be inserted through.

That is, referring to FIG. 13 and FIG. 14 together, the superposed body 203 is configured such that the positive electrode main body connecting portions are inserted into the slits 207c so that the positive electrode main body and the negative electrode main body 207a are alternately overlapped in one direction. Yes.
The “positive electrode main body” is a portion of the positive electrode 205 that overlaps the negative electrode main body 207a in the plan view of FIG. The “positive electrode main body connecting portion” is a portion of the positive electrode 205 that overlaps with the slit 207c in the plan view of FIG.

[Positive electrode structure]
As shown in FIG. 14, the positive electrode structure 204 includes a positive electrode 205 and a separator 206 that covers the positive electrode 205. The positive electrode structure 204 has a strip shape extending in one direction in plan view.

Specifically, referring to FIG. 13 and FIG. 14 together, in the developed state of the positive electrode structure 204, the positive electrode structure 204 has a plurality of (for example, eight in this embodiment) structures arranged in one direction. A body main body 204a and a structure body connecting portion 204b that connects two adjacent structure bodies 204a are provided.
The “structure body 204a” is a portion of the positive electrode structure 204 that overlaps the negative electrode body 207a in plan view of FIG. The “structure body connecting portion 204b” is a portion of the positive electrode structure 204 that overlaps the slit 207c in the plan view of FIG.

The structure main body 204a has substantially the same size as the structure main body connecting portion 204b in the width direction of the positive electrode structure 204.
The structure body connecting portion 204b is disposed at a position overlapping the structure axis 4L in a plan view when the positive electrode structure 204 is expanded.

[Positive electrode]
The positive electrode 205 has a rectangular strip shape extending in one direction in a plan view of FIG.

[Separator]
The separator 206 has a rectangular strip shape extending in one direction in a plan view of FIG. The length of the separator 206 in the longitudinal direction is shorter than the length of the positive electrode 205 in the longitudinal direction. That is, the length of the separator 206 in the longitudinal direction is such that the extended portion 231 of the positive electrode 205 is exposed.

[Negative electrode]
The negative electrode 207 has a strip shape extending in one direction. Specifically, in the developed state of the negative electrode 207 shown in FIG. 15, the negative electrode 207 includes a plurality of (e.g., eight in this embodiment) negative electrode bodies 207 a arranged in one direction and two adjacent negative electrodes. A negative electrode main body connection portion 207b for connecting the main body 207a. In the figure, reference numeral 221 denotes an extended portion of the negative electrode 207.

The negative electrode main body 207 a has substantially the same size as the negative electrode main body connecting portion 207 b in the width direction of the negative electrode 207.
A slit 207c having a length in the width direction of the negative electrode main body connection portion 207b (that is, the width direction of the negative electrode 207) is formed in the negative electrode main body connection portion 207b.

  In the plan view of FIG. 15, the slit 207 c has a rectangular shape extending in the width direction of the negative electrode 207. As shown in FIG. 13, the length of the slit 207c in the longitudinal direction is slightly longer than the width of the structure body connecting portion 204b.

  The planar shape of the slit 207c is not limited to a rectangular shape, and may be a shape other than a rectangular shape such as an elliptical shape. That is, the planar shape of the slit 207c only needs to be a shape that allows the structure body connecting portion 204b to be inserted.

[Battery manufacturing method]
FIG. 16 is a process diagram illustrating the method for manufacturing the battery according to the second embodiment.
The second embodiment is different from the first embodiment in that the structure body connecting portion 204b is inserted into the slit 207c in the overlapping body forming step.
Hereinafter, an example of the battery manufacturing method according to the second embodiment will be described. In the second embodiment, the description of the same steps as the manufacturing steps in the first embodiment is omitted.

  As shown in FIG. 16, a slit 207c having a length in the width direction of the negative electrode main body connecting portion 207b (that is, the width direction of the negative electrode 207) is formed in the negative electrode main body connecting portion 207b before the overlapping body forming step. For example, in the electrode processing step, the negative electrode sheet is cut out with a slitter or the like to obtain the negative electrode 207 in which the slits 207c are formed.

  In addition, before the superposed body forming step, the positive electrode 205 is integrated with the separator 206, and a plurality of structure bodies 204a arranged in one direction are connected to two adjacent structure bodies 204a. A band-like positive electrode structure 204 having a body main body connection portion 204b is formed.

  Next, in the overlapping body forming step, the structure body connecting portions 204b are inserted through the slits 207c so that the structure bodies 204a and the negative electrode bodies 207a overlap alternately in one direction.

  That is, the positive electrode main body connecting portion is inserted into the slit 207c so that the positive electrode main body and the negative electrode main body 207a overlap each other in one direction. For example, in the superposed body forming step, the positive electrode structure 204 is moved in the direction of the arrow shown in FIG. A body 203 (see FIG. 13) is formed.

  Next, in the spelling step, the stacked body 203 is folded into a spelling shape to obtain a laminated body. Then, after impregnating the electrolyte solution (not shown) in the laminate, the laminate impregnated with the electrolyte solution is enclosed in the exterior body 10 to complete the battery of this embodiment.

  As described above, in the present embodiment, the negative electrode main body connecting portion 207b is formed with the slit 207c having a length in the width direction of the negative electrode 207, and the stacked body 203 has the positive electrode main body and the negative electrode main body 207a arranged in one direction. The positive electrode main body connecting portions are inserted into the slits 207c so as to overlap with each other.

  According to the present embodiment, the movement of the positive electrode main body connection portion in the width direction of the stacked body 203 is restricted by inserting the positive electrode main body connection portion into the slit 207c. Therefore, it is possible to more effectively suppress the displacement between the positive electrode main body and the negative electrode main body 207a.

  In this embodiment, the slit 207c is formed in the negative electrode main body connection portion 207b, the positive electrode 205 is a strip-like positive electrode structure 204 integrated with the separator 206, and the positive electrode structure 204 is aligned in one direction. A plurality of structure main bodies 204a and a structure main body connecting portion 204b for connecting two adjacent structure main bodies 204a. The superposition body 203 includes a structure main body 204a and a negative electrode main body 207a. The structure body connecting portions 204b are configured to be inserted through the slits 207c so as to alternately overlap in the one direction.

  According to the present embodiment, as compared with the case where the positive electrode 205 is separated from the separator 206, it is possible to more effectively suppress the position of the positive electrode 205 from shifting. In addition, the structure body connecting portion 204b is inserted into the slit 207c, so that the movement of the structure body connecting portion 204b in the width direction of the superposed body 203 is restricted, and the movement of the positive electrode body connecting portion is restricted. . Therefore, it is possible to more effectively suppress the displacement between the positive electrode main body and the negative electrode main body 207a.

  In this embodiment, the slit 207c is formed in the negative electrode main body connection portion 207b. However, the present invention is not limited to this, and the slit may be formed in the positive electrode main body connection portion. That is, either one of the positive electrode main body connection portion or the negative electrode main body connection portion is formed with a slit having a length in the one width direction so that the positive electrode main body and the negative electrode main body are alternately overlapped in one direction. In addition, either the positive electrode main body connection portion or the negative electrode main body connection portion may be configured to be inserted through the slit.

<Third Embodiment>
FIG. 17 is a plan view showing a developed state of the stacked body 303 according to the third embodiment, and corresponds to FIG.
The third embodiment is different from the first embodiment in that the negative electrode side notch non-forming portion 307d enters the structure side notch 304c and the structure side notch non forming portion 304d enters the negative electrode side notch 307c. . Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

[Superposition]
As shown in FIG. 17, in the unfolded state of the superposed body 303, the superposed body 303 is arranged on the structure side cutout 304c so that the structure main body 304a and the negative electrode main body 307a are alternately overlapped in one direction. The not-not-formed part 307d enters, and the structure-side notched part 304d enters the negative-side notch 307c.

That is, referring to FIG. 17 and FIG. 18 together, the stacked body 303 has the negative electrode side notch non-forming part 307d in the positive electrode side notch so that the positive electrode body and the negative electrode body 307a overlap each other in one direction. The positive electrode side notch non-forming part is inserted into the negative electrode side notch 307c.
The “positive electrode main body” is a portion of the positive electrode 305 that overlaps the negative electrode main body 307a in the plan view of FIG. The “positive electrode main body connecting portion” is a portion that connects two adjacent positive electrode main bodies. “Positive electrode side cutout” is a portion of the positive electrode main body connecting portion that overlaps with the structure side cutout 304c in a plan view of FIG. The “positive side notch non-forming part” is a part of the positive electrode main body connection part that overlaps the structure side notch non-forming part 304d in plan view.

[Positive electrode structure]
As illustrated in FIG. 18, the positive electrode structure 304 includes a positive electrode 305 and a separator 306 that covers the positive electrode 305. The positive electrode structure 304 has a strip shape extending in one direction in plan view. Specifically, in the expanded state of the positive electrode structure 304, the positive electrode structure 304 includes a plurality of (e.g., eight in this embodiment) structure bodies 304a arranged in one direction and two adjacent structures. And a structure body connection portion 304b for connecting the body 304a.

  A structure-side cutout 304c extending in the width direction is formed on one side in the width direction of the structure body connecting portion 304b. The structure-side notch 304c is recessed to a position where it overlaps the structure axis 4L in plan view when the positive electrode structure 304 is expanded. On the other side in the width direction of the structure body connecting portion 304b, a structure-side notch non-forming portion 304d is formed.

[Positive electrode]
The positive electrode 305 has a strip shape extending in one direction in a plan view of FIG.

[Separator]
The separator 306 has a strip shape extending in one direction in a plan view of FIG. The length of the separator 306 in the longitudinal direction is shorter than the length of the positive electrode 305 in the longitudinal direction. That is, the length of the separator 306 in the longitudinal direction is such that the extension 331 of the positive electrode 305 is exposed.

[Negative electrode]
The negative electrode 307 has a strip shape extending in one direction. Specifically, in the developed state of the negative electrode 307 shown in FIG. 19, the negative electrode 307 includes a plurality of (for example, eight in this embodiment) negative electrode bodies 307 a arranged in one direction and two adjacent negative electrodes. A negative electrode main body connecting portion 307b for connecting the main body 307a. Note that reference numeral 321 in the figure is an extended portion of the negative electrode 307.

  A negative electrode side notch 307c extending in the width direction is formed on one side of the negative electrode main body connecting portion 307b in the width direction. The negative electrode side notch 307c is recessed to a position overlapping the negative electrode axis 7L in a plan view when the negative electrode 307 is expanded. On the other side in the width direction of the negative electrode main body connecting portion 307b, a negative electrode-side notched portion 307d is formed.

[Battery manufacturing method]
FIG. 20 is a process diagram illustrating the method for manufacturing the battery according to the third embodiment.
In the third embodiment, the negative electrode side notch non-forming portion 307d is inserted into the structure side notch 304c and the structure side notch non forming portion 304d is inserted into the negative electrode side notch 307c in the overlapping body forming step. This is different from the first embodiment.
Hereinafter, an example of the battery manufacturing method according to the third embodiment will be described. In the third embodiment, description of the same steps as the manufacturing steps in the first embodiment is omitted.

  As shown in FIG. 20, the positive electrode side notch is formed on one side in the width direction of the positive electrode main body connecting portion and the positive electrode side notch is formed on the other side in the width direction of the positive electrode main body connecting portion before the overlapping body forming step. A non-forming part is provided. On the other hand, the negative electrode side notch 307c is formed on one side in the width direction of the negative electrode main body connection portion 307b, and the negative electrode side notch non-forming portion 307d is provided on the other side in the width direction of the negative electrode main body connection portion 307b. For example, in the electrode processing step, the positive electrode sheet is cut out by a slitter or the like to obtain the positive electrode 305 in which the positive electrode side cutout is formed. On the other hand, the negative electrode sheet is cut out with a slitter or the like to obtain the negative electrode 307 in which the negative electrode side cutout 307c is formed.

  In addition, before the superposed body forming step, the structure in which the positive electrode 305 is integrated with the separator 306 and a plurality of structure bodies 304a arranged in one direction and two adjacent structure bodies 304a are connected. A belt-like positive electrode structure 304 having a body main body connection portion 304b is formed. Further, the structure-side notch 304c is formed on one side in the width direction of the structure body connecting portion 304b, and the structure-side notch non-forming portion 304d is provided on the other side in the width direction of the structure body connecting portion 304b.

  Next, in the overlapping body forming step, the negative electrode side notch non-forming portion 307d is inserted into the structure side cutout 304c so that the structure main body 304a and the negative electrode main body 307a overlap each other alternately in one direction, and the negative electrode side The structure-side notch non-forming portion 304d is inserted into the notch 307c.

  That is, the negative electrode side notch non-forming portion 307d is inserted into the positive electrode side notch so that the positive electrode main body and the negative electrode main body 307a are alternately overlapped in one direction, and the positive electrode side notch non forming portion is inserted into the negative electrode side notch 307c. Get in. For example, in the stacked body forming step, the structure-side cutout 304c, the negative-electrode-side cutout 307c, and the direction of the arrow shown in FIG. 20 are opposed to each other, and then the positive-electrode structure 304 and the negative electrode 307 are overlapped. An overlapping body 303 (see FIG. 17) is formed.

  Next, in the spelling step, the stacked body 303 is folded into a spelling shape to obtain a laminated body. Then, after impregnating the electrolyte solution (not shown) in the laminate, the laminate impregnated with the electrolyte solution is enclosed in the exterior body 10 to complete the battery of this embodiment.

  As described above, in the present embodiment, a positive electrode side notch is formed on one side in the width direction of the positive electrode main body connecting portion, and a positive electrode side notch non-forming portion is formed on the other side in the width direction of the positive electrode main body connecting portion. A negative electrode side notch 307c is formed on one side in the width direction of the negative electrode main body connecting portion 307b, and a negative electrode side notch non-forming portion 307d is provided on the other side in the width direction of the negative electrode main body connecting portion 307b. In the stacked body 303, the negative electrode side notch non-forming part 307d enters the positive electrode side notch so that the positive electrode body and the negative electrode body 307a overlap with each other in the one direction, and the negative electrode side notch 307c has the positive electrode side. A not-not-formed part is formed.

  According to this embodiment, the negative electrode side notch non-forming portion 307d enters the positive electrode side notch, and the positive electrode side notch non forming portion enters the negative electrode side notch 307c. Movement of the positive electrode main body connection portion and the negative electrode main body connection portion 307b in the direction is restricted. Therefore, it can suppress more effectively that a position of a positive electrode main part and a negative electrode main part 307a shifts.

  In the present embodiment, the positive electrode 305 is a strip-like positive electrode structure 304 integrated with a separator 306, and the positive electrode structure 304 is adjacent to a plurality of structure bodies 304a arranged in one direction. A structure body connection portion 304b that connects two matching structure body bodies 304a, and a structure body notch 304c is formed on one side in the width direction of the structure body connection portion 304b. On the other side in the width direction, a structure-side cutout non-forming portion 304d is provided, and the stacked body 303 has a structure-side cutout so that the structure body 304a and the negative electrode body 307a alternately overlap in the one direction. The negative electrode side notch non-forming part 307d enters the 304c, and the structure side notch non-forming part 304d enters the negative electrode notch 307c.

  According to this embodiment, compared with the case where the positive electrode 305 is separated from the separator 306, the position of the positive electrode 305 can be suppressed more effectively. In addition, since the negative electrode side notch non-forming part 307d enters the structure side notch 304c and the structure side notch non forming part 304d enters the negative electrode side notch 307c, The movement of the structure main body connection portion 304b and the negative electrode main body connection portion 307b is restricted. Therefore, it can suppress more effectively that a position of a positive electrode main part and a negative electrode main part 307a shifts.

  The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, a secondary battery has been described as an example of an electrochemical cell. However, the present invention is not limited thereto, and the above-described configuration may be applied to an electric double layer capacitor, a primary battery, and the like. Moreover, although the lithium ion secondary battery was mentioned as an example and demonstrated as a battery, not only this but secondary batteries other than lithium ion secondary batteries, such as a metal lithium secondary battery, may be sufficient.

  Moreover, although the said embodiment gave and demonstrated the example in which the positive electrode was covered with the separator, not only this but the negative electrode may be covered with the separator.

  Moreover, in the said embodiment, although the example which encapsulated the laminated body in the exterior body and was used as the coin-type battery was given and demonstrated, it does not restrict to this but encloses a laminated body in a laminate pack, and electrically connects with a laminated body The connected lead wire may be configured to protrude from the laminate pack to the outside.

  Moreover, although the said embodiment gave and demonstrated the example which zigzags an overlapping body, not only this but an overlapping body may be wound, laminated | stacked, etc.

  In the above embodiment, the example in which the positive electrode is covered with the first separator and the second separator in the electrode covering step has been described. However, the present invention is not limited thereto, and the positive electrode is covered with a bag-shaped separator. May be.

  In the above embodiment, the binder material for the positive electrode is polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), polytetrafluoroethylene (PTFE), or the like, and the separator material is polypropylene (PP) or polyethylene. (PE) and other polyolefins and polytetrafluoroethylene (PTFE) have been described as examples. However, the present invention is not limited thereto, and any material that can heat-seal the positive electrode active material layer and the separator is used. Good.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Battery (electrochemical cell) 2 ... Laminated body 3,203,303 ... Superposition body 4,204,304 ... Positive electrode structure 4a, 204a, 304a ... Structure body 4b, 204b, 304b ... Structure body connection part 5, 205, 305 ... Positive electrode 5a ... Positive electrode body 5b ... Positive electrode body connection 6, 206, 306 ... Separator 7, 207, 307 ... Negative electrode 7a, 207a, 307a ... Negative electrode body 7b, 207b, 307b ... Negative electrode body connection Part 207c ... Slit 304c ... Structure side notch 304d ... Structure side notch non-forming part 307c ... Negative electrode side notch 307d ... Negative electrode side notch non-forming part S3 ... Positive electrode structure forming step S4 ... Overlapping body forming step

Claims (11)

A strip-shaped positive electrode having a plurality of positive electrode main bodies arranged in one direction and a positive electrode main body connecting portion connecting two adjacent positive electrode main bodies;
A strip-shaped negative electrode having a plurality of negative electrode bodies arranged side by side in the one direction, and a negative electrode body connection portion connecting two adjacent negative electrode bodies;
A separator disposed between the positive electrode and the negative electrode,
The positive electrode and the negative electrode are a band-like superposed body in which the positive electrode main body and the negative electrode main body are alternately overlapped in the one direction via the separator ,
The positive electrode is a belt-like shape having a plurality of structure bodies integrated with the separator and arranged in the one direction, and a structure body connection portion connecting two adjacent structure bodies. A positive electrode structure,
The external shape of the positive electrode is smaller than the external shape of the negative electrode,
The outer shape of the positive electrode structure is the same size as the outer shape of the negative electrode,
The superimposed body is configured by superimposing the positive electrode structure and the negative electrode so that the structure main body and the negative electrode main body alternately overlap in the one direction,
The electrochemical cell according to claim 1, wherein an outer shape of the structure body is the same as an outer shape of the negative electrode body .   2. The electrochemical cell according to claim 1, wherein the positive electrode main body connection portion and the negative electrode main body connection portion are shifted in opposite directions in the width direction of the stacked body. 3. The electrochemical cell according to claim 1, wherein the outer shape of the structure body has a circular shape having the same size as the outer shape of the negative electrode body. A structure-side cutout is formed on one side in the width direction of the structure body connection portion, and a structure-side cutout non-forming portion is provided on the other side in the width direction of the structure body connection portion,
A negative electrode side notch is formed on one side in the width direction of the negative electrode main body connection portion, and a negative electrode side notch non-forming portion is provided on the other side in the width direction of the negative electrode main body connection portion,
The stacked body has the negative-side cutout non-formed portion in the structure-side cutout so that the structure main body and the negative-electrode main body alternately overlap in the one direction, and the negative-piece-side cutout. 2. The electrochemical cell according to claim 1 , wherein the structure-side cutout non-forming part is formed. The electrochemical cell according to any one of claims 1 to 4 , wherein the stacked body is a stacked body folded in a zigzag shape. A strip-shaped positive electrode having a plurality of positive electrode main bodies arranged in one direction and a positive electrode main body connecting portion connecting two adjacent positive electrode main bodies;
A strip-shaped negative electrode having a plurality of negative electrode bodies arranged side by side in the one direction, and a negative electrode body connection portion connecting two adjacent negative electrode bodies;
A separator disposed between the positive electrode and the negative electrode, and an electrochemical cell manufacturing method comprising:
A superposed body forming step of superposing the positive electrode and the negative electrode over the separator so that the positive electrode main body and the negative electrode main body alternately overlap in the one direction to form a band-shaped superposed body. only including,
Prior to the superposed body forming step, the positive electrode is integrated with the separator, and a plurality of structural bodies arranged in one direction are connected to two adjacent structural bodies. And further including a positive electrode structure forming step as a band-shaped positive electrode structure having a connection part,
Before the positive electrode structure forming step, the external shape of the positive electrode is made smaller than the external shape of the negative electrode,
In the positive electrode structure forming step, the outer shape of the positive electrode structure is made the same size as the outer shape of the negative electrode,
In the superimposed body forming step, the positive electrode structure and the negative electrode are overlapped so that the structure main body and the negative electrode main body alternately overlap in the one direction,
In the positive electrode structure forming step, the outer shape of the structure main body is made the same size as the outer shape of the negative electrode main body . The electrochemical cell according to claim 6 , wherein in the superposed body forming step, the positive electrode main body connecting portion and the negative electrode main body connecting portion are shifted in opposite directions in the width direction of the superposed body. Production method. The positive electrode structure forming step, the positive electrode, was covered by being sandwiched between the resin of the first separator and the resin of the second separator of the separators, and said second separator and said first separator The method for producing an electrochemical cell according to claim 6 or 7 , wherein heat fusion is performed. The electrochemical according to any one of claims 6 to 8, wherein in the positive electrode structure forming step, the outer shape of the structure main body is a circular shape having the same size as the outer shape of the negative electrode main body. Cell manufacturing method. Before the superimposition body forming step, to form a-out structure side notch on one side in the width direction of the structure body connection part, the non-formed-out structure side notch on the other side in the width direction of the structure body connecting portion A negative electrode side notch is formed on one side in the width direction of the negative electrode main body connection portion, and a negative electrode side notch non-forming portion is provided on the other side in the width direction of the negative electrode main body connection portion,
In the superimposed body forming step, the negative electrode side notch non-forming portion is inserted into the structure side cutout so that the structure main body and the negative electrode main body alternately overlap in the one direction, and the negative electrode side The method for producing an electrochemical cell according to claim 6 , wherein the structure-side notch non-forming part is inserted into the notch. The method for producing an electrochemical cell according to any one of claims 6 to 10 , wherein after the superposed body forming step, the superposed body is folded into a zigzag shape to form a laminated body.

Images