JP2020202121A - Electrochemical cell and method for manufacturing the same - Google Patents

Abstract

To provide an electrochemical cell.SOLUTION: An electrochemical cell of the present invention has a belt-like positive electrode and a belt-like negative electrode, and comprises: an electrode lamination structure that is configured by winding a laminate obtained by shifting one side end edges and the other side end edges in the width direction of the positive electrode and negative electrode in the width direction by a predetermined width, on both faces of at least one of the positive electrode and negative electrode, with a separator layer composed of a coating hardened layer formed by excluding one side end edge in a width direction or the other side end edge in the width direction of at least one of the positive electrode and negative electrode, so as to circle around an arbitrary winding central axis; a positive electrode side container in which the wound one side end edge in the width direction of the positive electrode is electrically connected to a positive electrode projection projecting outward from the one side end edge of the negative electrode adjacent to the end edge; and a negative electrode side container in which the wound other side end edge in the width direction of the negative electrode is electrically connected to a negative electrode projection projecting outward from the other side end edge of the positive electrode adjacent to the end edge, and that defines an accommodation space for accommodating the electrode lamination structure together with the positive electrode side container.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrolytic chemical cell and a method for producing the same.

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

For example, as a porous separator for a battery, Patent Document 1 below describes a step of printing a thin layer of a separator precursor on an electrode and a step of vulcanizing this thin layer to change it into a microporous composite separator structure. A manufacturing method comprising the above is disclosed.
In Patent Document 2 below, the voids between the polymer solid electrolyte obtained by impregnating the stretched porous PTFE (polytetrafluoroethylene) with a polymer solid electrolyte resin solution and then removing the solvent, and the stretched porous PTFE. A composite polymer solid electrolyte membrane / electrode integrally molded body in which an electrode catalyst and an electrode filled with an electrode component containing a polymer solid electrolyte are integrally molded is described.
Further, as described in Patent Document 3 below, an electrode group is formed by winding a band-shaped positive electrode, a negative electrode, and a sheet-shaped separator, and the electrode group is formed of an exterior body composed of a positive electrode side container and a negative electrode side container. Electrochemical cells housed inside are known.

Japanese Unexamined Patent Publication No. 10-334877 Japanese Unexamined Patent Publication No. 08-329962 Japanese Unexamined Patent Publication No. 2016-100122

In the configuration of Patent Document 3, when the strip-shaped positive electrode and the negative electrode and the sheet-shaped separator are wound to form an electrode group, the positive electrode and the negative electrode are wound by alternately shifting them in the width direction, and the electrodes are formed. A positive electrode projecting portion is formed on one end surface of the group, a negative electrode protruding portion is formed on the other end surface of the electrode group, and these are connected to the inner surface of the positive electrode side container and the inner surface of the negative electrode side container.
However, when the structure described in Patent Document 3 is adopted, there is a problem that a short circuit risk between the positive electrode and the negative electrode occurs when the positive electrode, the negative electrode, and the separator are misaligned.
In order to avoid the risk of short circuit, it is necessary to increase the width of the separator, but if the width of the separator is increased more than necessary, the volumetric efficiency of the battery deteriorates, and as a result, the battery capacity density per volume decreases. There is a problem to be done. Further, when the positive electrode protruding portion and the negative electrode protruding portion for connecting the positive electrode side container and the negative electrode side container are lengthened to ensure reliable conduction, the volume of the active material layer provided on the positive electrode side and the negative electrode side is reduced. There is a problem that the volume efficiency of the battery deteriorates, and as a result, the battery capacity density per volume decreases.

The present invention has been made in view of the conventional circumstances as described above, and in the case of an electrochemical cell in which a strip-shaped positive electrode and a negative electrode are wound via a separator to form an electrode laminated structure, a short risk may occur. It is an object of the present invention to provide an electrochemical cell capable of suppressing the volumetric efficiency as an electrochemical cell and a method for producing the same.

(1) In order to solve the above-mentioned problems, the electrolytic chemical cell according to one embodiment of the present invention has a band-shaped positive electrode and a band-shaped negative electrode, and the positive electrode and the positive electrode are formed on at least one of the front and back surfaces of the positive electrode and the negative electrode. The positive electrode and the negative electrode are placed on one side edge in the width direction of the positive electrode and the negative electrode via a separator layer composed of a coating film cured layer formed by excluding at least one side edge in the width direction or the other side edge in the width direction of the negative electrode. An electrode laminated structure formed by winding a laminated body in which the edges on the other side and the other side are shifted by a predetermined width in the width direction and laminated so as to orbit around an arbitrary winding central axis, and the wound positive electrode. A positive electrode side container in which a positive electrode projecting portion that protrudes outward from one side edge of the negative electrode adjacent to the edge on one side in the width direction is electrically connected, and the other side in the width direction of the wound negative electrode. A negative electrode projecting portion that protrudes outward from the other side edge of the positive electrode adjacent to the edge is electrically connected to the edge of the electrode, and a storage space for accommodating the electrode laminated structure is defined together with the positive electrode side container. It is characterized by having a negative electrode side container.

In the case of an electrode laminate having a structure in which a positive electrode and a negative electrode are wound with a coating film curing type separator layer, the separator layer reliably insulates and separates the positive electrode and the negative electrode, so that even if the positive electrode and the negative electrode are miswound. It is possible to provide an electrolytic chemical cell with less short-circuit risk.
Further, by connecting the positive electrode protruding portion formed on one end face side of the electrode laminated structure to the positive electrode side container and connecting the negative electrode protruding portion formed on the other end face side to the negative electrode container, a tab for conduction or the like can be provided. Can be connected without using it separately. Therefore, the tab for conduction can be omitted, and the electrode can be arranged in the space where the tab for conduction is provided, so that an electrochemical cell having a high battery capacity density per volume can be provided.
On the other hand, if the tape-shaped separator is wound together with the positive electrode and the negative electrode, an internal short circuit may occur if the winding is misaligned. Simply increasing the separator to avoid the risk of internal shorts reduces the battery capacity density per volume as an electrical cell. Therefore, an electrochemical cell including a positive electrode and a negative electrode provided with a coating film-curable separator layer can provide an electrochemical cell that does not cause a decrease in battery capacity density per volume.

(2) In the electrochemical cell according to one embodiment of the present invention, the strip-shaped positive electrode is formed on a strip-shaped positive electrode side current collector sheet and a portion on both the front and back surfaces of the current collector sheet excluding the positive electrode protruding portion. A negative electrode active material layer composed of a positive electrode active material layer, wherein the band-shaped negative electrode is formed on a band-shaped negative electrode side current collector sheet and a portion on both front and back surfaces of the current collector sheet excluding the negative electrode protruding portion. A positive electrode side end insulating layer is formed to cover the front and back surfaces of the end edges on both ends in the length direction of the positive electrode with a predetermined width, and the front and back surfaces of the end edges on both ends in the length direction of the negative electrode have a predetermined width. It is preferable that an insulating layer at the end on the negative electrode side is formed.

By covering the necessary part of the positive electrode consisting of the positive electrode side current collector sheet and the positive electrode active material layer with the separator layer, and covering the necessary part of the negative electrode consisting of the negative electrode side current collector sheet and the negative electrode active material layer with the separator layer, the winding is performed. A structure in which the positive electrode and the negative electrode are insulated can be realized in the electrode laminated structure of the structure.
Further, both ends in the length direction of the positive electrode are covered with an insulating layer at the end on the positive electrode side over a predetermined width, and both ends in the length direction of the negative electrode are covered with an insulating layer at the end on the negative electrode side over a predetermined width to form a wound structure. When the electrode laminated structure is constructed, the end insulating layer can be arranged around the portion where a part of the current collector sheet may be exposed at the start portion and the end portion of the winding, and the insulation is provided. Can provide a high structure.

(3) In the electrochemical cell according to one embodiment of the present invention, a separator layer covering the negative electrode active material layer is formed on both the front and back surfaces of the negative electrode, and the separator layer located in the vicinity of the negative electrode protruding portion is located in the width direction of the separator layer. Both the side edge and the other edge of the separator layer located on the other side in the negative electrode width direction are outside the electrode laminated structure from the widthwise edge of the positive electrode active material layer adjacent thereto. It is characterized by being projected to.

In the electrode laminated structure in which the positive electrode and the negative electrode are wound, the edge of the separator layer located at both ends in the width direction of the negative electrode in the separator layer covering the negative electrode active material layer is the positive electrode active material layer adjacent to the edge. It is preferable that it protrudes outward from the edge in the width direction.
Due to the structure of the electrochemical cell, it is necessary to make the negative electrode width larger than the positive electrode width so that the positive electrode edge does not protrude to the outside of the negative electrode edge. Therefore, by adopting a structure in which the edge of the separator layer protrudes outward from the widthwise edge of the positive electrode active material layer, it is possible to prevent the positive electrode edge from protruding outward from the negative electrode edge. Further, when the positive electrode and the negative electrode are wound to form an electrode laminated structure, the widthwise edge of the positive electrode can be arranged inside the widthwise edge of the negative electrode even if some winding disorder occurs.

(4) In the electrochemical cell according to one embodiment of the present invention, a positive electrode side extending portion covering the length direction end side end face of the positive electrode is formed in the positive electrode side end insulating layer, and the negative electrode side end portion is insulated. It is preferable that the layer is formed with an extension portion on the negative electrode side that covers the end surface on the end side in the length direction of the negative electrode.

By providing the positive electrode side extension, the insulation of both end faces of the positive electrode side current collector sheet can be improved, and by providing the negative electrode side extension, the insulation of both end faces of the negative electrode side current collector sheet can be improved. Therefore, when an electrode laminated structure having a wound structure is constructed, the insulating properties of the winding start portion and the winding end portion can be further improved.

(5) In the electrochemical cell according to one embodiment of the present invention, it is preferable that the positive electrode side container and the positive electrode protruding portion are electrically connected via a conductive material.
By connecting the positive electrode protruding portion to the positive electrode side container via the conductive material, reliable conduction between the positive electrode and the positive electrode side container can be obtained.

(6) In the electrochemical cell according to one embodiment of the present invention, it is preferable that the negative electrode side container and the negative electrode protruding portion are electrically connected via a conductive material.
By connecting the negative electrode protruding portion to the negative electrode side container via the conductive material, reliable conduction between the negative electrode and the negative electrode side container can be obtained.

(7) In the electrochemical cell according to one embodiment of the present invention, it is preferable that the positive electrode side end insulating layer and the negative electrode side end insulating layer are made of insulating tape.

By forming the end insulating layer from insulating tape, both ends of the positive electrode or negative electrode current collector sheet can be easily insulated with a required width. As a result, in the electrode laminated structure having a wound structure, it is possible to provide a structure in which better insulating properties are ensured at the winding start portion and the winding end portion.

(8) The method for producing an electrochemical cell according to one embodiment of the present invention is the method for producing an electrochemical cell according to any one of (2) to (6), on both front and back surfaces of a strip-shaped positive electrode. The step of forming the positive electrode side end insulating layer, the step of forming the negative electrode side end insulating layer on the front and back surfaces of both ends of the strip-shaped negative electrode, the positive electrode side current collector sheet on which the end insulating layer is formed, and the above. A step of forming an insulating coating film on at least one of the negative electrode side current collector sheets except for one side edge in the width direction of the front and back surfaces of the sheet, and a step of curing the insulating coating film to form a separator layer. The negative electrode side current collector sheet and the positive electrode side current collector sheet are overlapped with each other via the separator layer by shifting one side edge in the width direction and the other side edge in the width direction by a predetermined width in the width direction. A step of forming an electrode laminated structure by winding along an arbitrary winding center axis while matching, and one side edge of the negative electrode side current collector sheet are projected to one side end surface of the electrode laminated structure by the winding. The negative electrode side connecting step of electrically connecting the negative electrode side protruding portion formed in the above method to the negative electrode side container and the other side edge of the positive electrode side current collector sheet are projected to the other side end surface of the electrode laminated structure by the winding. It is characterized by including a positive electrode side connecting step of electrically connecting the positive electrode protruding portion formed in the above to the positive electrode side container.

A separator layer obtained by curing an insulating coating is formed on at least one of the negative electrode and the positive electrode, and the negative electrode and the positive electrode are wound around the separator layer to obtain an electrode laminated structure having excellent insulating properties between the negative electrode and the positive electrode. be able to.
If the electrode laminate has a structure in which a positive electrode and a negative electrode are wound with a coating film curing type separator layer, the separator layer can be accurately formed at the required positions of the positive electrode and the negative electrode, and the separator layer can be reliably formed between the positive electrode and the negative electrode. Therefore, it is possible to provide an electrolytic chemical cell in which there is no risk of short circuit even if the positive electrode and the negative electrode are unwound during winding.

(9) In the method for manufacturing an electrochemical cell according to an embodiment of the present invention, a negative electrode having a negative electrode active material layer formed on a portion other than the negative electrode side current collector sheet and one side edge thereof is used as the negative electrode. As the positive electrode, a positive electrode having the positive electrode side current collector sheet and a positive electrode active material layer formed on a portion other than the other side edge is used, and the negative electrode side current collector sheet is provided by the negative electrode side end insulating layer. The negative electrode active material layer located at both ends of the front and back surfaces of the positive electrode side and the negative electrode active material layers located at both ends thereof are covered, and the positive electrode active material located at both ends of the front and back surfaces of the positive electrode side current collector sheet and the positive electrode active material located at both ends of the positive electrode side current collector sheet. It is characterized by covering a material layer.

An end insulating layer is provided on each of the negative electrode by the negative electrode side current collector sheet provided with the negative electrode active material layer and the positive electrode by the positive electrode side current collector sheet provided with the positive electrode active material layer, and these negative electrodes and the positive electrode are wound around. Thereby, the end insulating layer can be arranged at the winding start portion and the winding end portion, and an electrode laminated structure having excellent insulation property with less risk of short circuit at the winding start portion and the winding end portion is provided. it can.

(10) In the method for producing an electrochemical cell according to an embodiment of the present invention, when the positive electrode protruding portion is electrically connected to the positive electrode side container, a paste-like positive electrode side conductivity applied to the inner surface of the positive electrode side container. It is preferable to connect via a material.
By connecting via a paste-like conductive material on the positive electrode side, good conduction between the protruding portion of the positive electrode and the container on the positive electrode side can be obtained.

(11) In the method for manufacturing an electrochemical cell according to an embodiment of the present invention, when the negative electrode protruding portion is electrically connected to the negative electrode side container, a paste-like negative electrode side conductivity applied to the inner surface of the negative electrode side container. It is preferable to connect via a material.
By connecting via a paste-like conductive material on the negative electrode side, good conduction between the protruding portion of the negative electrode and the container on the negative electrode side can be obtained.

(12) In the method for manufacturing an electrochemical cell according to an embodiment of the present invention, the positive electrode side end insulating layer to be formed on the positive electrode side current collector sheet is formed by attaching an insulating tape, and the negative electrode side current collector is formed. It is preferable that the negative electrode side end insulating layer to be formed on the body sheet is formed by attaching an insulating tape.

When forming the end insulating layer, according to the attachment of the insulating tape, the edge insulation of the required width is performed regardless of whether it is the edge of the positive electrode side current collector sheet or the edge of the negative electrode side current collector sheet. Layers can be easily formed. An electrode laminated structure having a low risk of short circuit can be formed by using a positive electrode and a negative electrode provided with an end insulating layer made of an insulating tape, and an electrochemical cell having a low risk of short circuit can be obtained.

(13) In the method for manufacturing an electrochemical cell according to one embodiment of the present invention, a plurality of positive electrode side current collector sheets are connected in a straight strip shape via the positive electrode side end insulating layer, and a plurality of negative electrode side current collector sheets are connected. The electric body sheets are connected in a straight line in a strip shape via the negative electrode side end insulating layer, and the negative electrode side current collector sheets connected to the connected plurality of positive electrode side current collector sheets are sequentially provided to the winding step. Is preferable.

A plurality of positive electrode side current collector sheets are linearly connected via a positive electrode side end insulating layer, or a plurality of negative electrode side current collector sheets are linearly connected via a connecting insulating tape. If used in the process, the electrode laminated structure can be continuously manufactured by sequentially supplying the positive electrode side current collector sheet and the negative electrode side current collector sheet to the winding process.

According to the present invention, in the electrode laminate having a structure in which a positive electrode and a negative electrode are wound with a coating film curable separator layer, the positive electrode and the negative electrode can be reliably separated by the separator layer, so that the positive electrode and the negative electrode are unwound. It is possible to provide an electrolytic chemical cell with less short-circuit risk even if a small amount of the above occurs.

Sectional drawing of the secondary battery (electrochemical cell) of 1st Embodiment which concerns on this invention. The perspective view which shows the state of laminating the positive electrode and the negative electrode with a separator layer used for the secondary battery of the same embodiment for winding. The electrodes used for manufacturing the secondary battery shown in FIG. 1 are shown. In FIG. 1, a negative electrode active material layer is formed on a current collector sheet for a negative electrode, and end insulating layers are formed at both ends in the length direction. (B) is a plan view showing the negative electrode side winding electrode sheet on which the coating film curing type separator layer is formed, (C) is a side view showing the state shown in (B), (D). Is a plan view showing a state in which a positive electrode active material layer is formed on a current collector sheet for a positive electrode and end insulating layers are formed at both ends in the length direction, and (E) is a positive electrode having a coating film curable separator layer formed. A plan view showing the side winding electrode sheet, (F) shows an electrode laminated structure in which the negative electrode side winding electrode sheet shown in (B) and the positive electrode side winding electrode sheet shown in (E) are wound. Perspective view. It is a figure for showing an example of the manufacturing method about the secondary battery of 1st Embodiment which concerns on this invention, and is the sectional view which shows the example of the state which attached the gasket to the inside of the positive electrode can. It is a figure for showing an example of the manufacturing method, and is the cross-sectional view which shows the state which applied the conductive material to the bottom surface of the positive electrode can. It is a figure for showing an example of the manufacturing method, and is the cross-sectional view which shows the state which accommodated the electrode laminated structure in the positive electrode can which coated the conductive material. Sectional drawing of the secondary battery (electrochemical cell) of 2nd Embodiment which concerns on this invention. A plan view showing a state in which a plurality of strip-shaped negative electrode side winding electrode sheets are linearly connected via insulating tape.

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

<First Embodiment>
FIG. 1 is a cross-sectional view showing a first embodiment in which the electrolytic chemical cell according to the present invention is applied to a secondary battery.
As shown in FIG. 1, the secondary battery 1 of the present embodiment is a so-called button-type secondary battery 1, and is an electrode laminate housed in the exterior body 2 together with an electrolytic solution (not shown). It has a structure 3. As the electrolytic solution, an electrolytic solution in which a supporting salt is dissolved in a non-aqueous solvent is preferably used.

The exterior body 2 has a circular shape in a plan view. Specifically, the exterior body 2 is assembled to the bottomed tubular positive electrode side container 11 via a gasket 12 and forms a storage space S between the positive electrode side container 11 and the positive electrode side container 11. It has a tubular negative electrode side container 13.
In the embodiment shown in FIG. 1, the central axes of the positive electrode side container 11 and the negative electrode side container 13 are arranged on a common axis. Hereinafter, this common axis is referred to as an axis O, the negative electrode side container 13 side along the axis O direction is referred to as an upper side, and the positive electrode side container 11 side is referred to as a lower side, and is orthogonal to the axis O in a plan view from the axis O direction. The direction of rotation is referred to as the radial direction, and the direction of orbiting around the axis O is called the circumferential direction.

The positive electrode side container 11 and the negative electrode side container 13 are formed by drawing, for example, a metal plate material such as a stainless steel plate. In the illustrated example, the inner diameter of the positive electrode side container 11 is larger than the outer diameter of the negative electrode side container 13.
The gasket 12 has an annular shape arranged coaxially with the axis O, and is fitted in the peripheral wall portion 11a of the positive electrode side container 11. The gasket 12 is formed with a groove portion 14 that holds the peripheral wall portion 13a of the negative electrode side container 13 over the entire circumference. The negative electrode side container 13 is fixed to the positive electrode side container 11 by caulking the peripheral wall portion 11a of the positive electrode side container 11 inward in the radial direction while the peripheral wall portion 13a is held in the groove portion 14 of the gasket 12. The gasket 12 is formed of an insulating material such as a resin material (for example, polypropylene (PP)).

The electrode laminated structure 3 has a structure in which a band-shaped positive electrode 21 and a band-shaped negative electrode 22 described below are wound in a spiral shape in a plan view in a state of being overlapped with each other slightly displaced in the width direction.
As shown in FIG. 2, the negative electrode 22 is a pair of strips coated on both the front and back surfaces of the negative electrode side current collector sheet 32, which has a fixed width band shape in the unfolded state before winding, and the negative electrode side current collector sheet 32. The negative electrode active material layer 33 and the negative electrode side separator layer 35 made of a coating film cured layer provided so as to cover the negative electrode active material layer 33 are provided.
A region having a constant width and not coated with the negative electrode active material layer 33 is formed on one side edge in the width direction (right back edge in FIG. 2) of the negative electrode side current collector sheet 32, and the negative electrode side collection of this region is formed. A negative electrode protruding portion 34, which will be described later, is formed from the electric body sheet 32.

The negative electrode active material layer 33 is formed to have a smaller width along the axis O direction than the negative electrode side current collector sheet 32, but the length of the negative electrode active material layer 33 is equivalent to the length of the negative electrode side current collector sheet 32. It is said that. Therefore, the end face of the negative electrode side current collector sheet 32 in the length direction and the end face of the negative electrode active material layer 33 in the length direction are formed flush with each other. Further, the widthwise other end surface of the negative electrode side current collector sheet 32 (left front end surface in FIG. 2) and the width direction other end surface of the negative electrode active material layer 33 (left front end surface in FIG. 2) are formed flush with each other. ing.

The negative electrode side separator layer 35 has a band-shaped main coating portion 35a that covers the negative electrode active material layers 33 on both the front and back surfaces of the negative electrode side current collector sheet 32. Further, on one side (right back side in FIG. 2) close to the negative electrode protruding portion 34 in the width direction of the main covering portion 35a, the auxiliary covering portion 35b covering the edge of the negative electrode active material layer 33 on the side close to the negative electrode protruding portion 34. Is formed, and on the other side (left front side in FIG. 2) of the main covering portion 35a, there is a connecting covering portion 35c that integrates the main covering portions 35a formed on both the front and back surfaces of the negative electrode side current collector sheet 32. It is formed.

As the coating material for forming the negative electrode side separator layer 35, for example, polyethylene oxide (PEO), polypropylene oxide (PPO), or a copolymer thereof and a lithium salt added as a supporting salt to the electrolytic solution are added to a solvent such as acetonitrile. A paint dissolved in is used. Alternatively, a solution obtained by dissolving polyvinylidene fluoride (PVDF) and a lithium salt added as a supporting salt to the electrolytic solution in a solvent such as N-methyl-2-pyrrolidone (NMP) may be used.
After applying these paints to form a coating film, the solvent is blown off by means such as heating, light irradiation, and drying to cure the coating film, whereby the negative electrode side separator layer 35 can be formed.
It is also effective to simultaneously dissolve inorganic or organic powders in the paint in order to reinforce the strength of the separator.

As shown in FIG. 2, the positive electrode 21 is a positive electrode side current collector sheet 25 having a band shape with a constant width in the unfolded state before winding, and a pair of positive electrode activities coated on both the front and back surfaces of the positive electrode side current collector sheet 25. A positive electrode side separator layer 27 composed of a material layer 26 and a coating film cured layer provided so as to cover the positive electrode active material layer 26 is provided. The constituent material of the positive electrode side separator layer 27 may be the same as the constituent material of the negative electrode side separator layer 35.
A region having a constant width and not coated with the positive electrode active material layer 26 is formed on the other side edge of the positive electrode side current collector sheet 25 in the width direction (left front side edge in FIG. 2), and the positive electrode side current collector in this region. A positive electrode protruding portion 28, which will be described later, is formed from the body sheet 25.

The positive electrode active material layer 26 is formed to have a smaller width along the axis O direction than the positive electrode side current collector sheet 25, but the length of the positive electrode active material layer 26 is equivalent to the length of the positive electrode side current collector sheet 25. It is said that. Therefore, the end face of the positive electrode side current collector sheet 25 in the length direction and the end face of the positive electrode active material layer 26 in the length direction are formed flush with each other. Further, the widthwise one-sided end surface of the positive electrode side current collector sheet 25 (right back side end surface in FIG. 2) and the width direction one side end surface of the positive electrode active material layer 26 (right back side end surface in FIG. 2) are flush with each other. It is formed.

The positive electrode side separator layer 27 has a band-shaped main covering portion 27a that covers the positive electrode active material layers 26 on both the front and back surfaces of the positive electrode side current collector sheet 25. Further, on one side of the main covering portion 27a in the width direction (right back side in FIG. 2), a connecting covering portion 27c that integrates the main covering portions 27a formed on both the front and back surfaces of the positive electrode side current collector sheet 25 is formed. Has been done. Further, on the other side (left front side in FIG. 2) of the main covering portion 27a in the width direction, an auxiliary covering portion 27b covering the edge of the positive electrode active material layer 26 on the side close to the positive electrode protruding portion 28 is formed.

The width of the negative electrode active material layer 33 along the axis O direction is formed to be slightly larger than the width of the positive electrode active material layer 26 along the same direction, and the positive electrode active material layer 26 and the negative electrode active material layer 33 shown in FIG. 1 are formed. The negative electrode active material layer 33 protrudes in the vertical direction with respect to the overlapping portion (overlapping portion) of the above.
In the electrode laminated structure 3, the region where the positive electrode active material layer 26 and the negative electrode active material layer 33 are overlapped constitutes the polymerized portion of the electrode.
Then, as shown in FIG. 1, the upper end portion of the negative electrode protruding portion 34 is electrically connected to the top wall portion 13b of the negative electrode side container 13 via the negative electrode side conductive material 36 described later, and the lower end portion of the positive electrode side protruding portion 28. Is electrically connected to the bottom wall portion 11b of the positive electrode side container 11 via the positive electrode side conductive material 31 described later.

As the positive electrode side current collector sheet 25, a metal foil made of aluminum, an aluminum alloy, stainless steel, or the like is preferably used. The thickness of the metal foil is, for example, about 10 μm.
Further, as a material for forming the positive electrode active material layer 26, for example, a positive electrode active material, a conductive auxiliary agent (for example, graphite, etc.), a binder (for example, polyvinylidene fluoride, etc.), a solvent (for example, an arbitrary solvent such as N-methylpyrrolidone, etc.) ) Are mixed to prepare a positive electrode slurry. Hereinafter, the coating liquid containing the constituent material for forming the positive electrode active material layer 26 is referred to as a “positive electrode slurry”. The positive electrode active material layer 26 can be formed by applying this positive electrode slurry to the positive electrode side current collector sheet 32 and drying it.

As the current collector sheet 32 on the negative electrode side, for example, a copper alloy or a metal foil such as pure copper or nickel is preferably used. The thickness of the metal foil is, for example, about 10 μm.
Further, as a material for forming the negative electrode active material layer 33, for example, a negative electrode active material, a conductive auxiliary agent (for example, graphite, etc.), a binder (for example, polyvinylidene fluoride, etc.), a solvent (for example, an arbitrary solvent such as N-methylpyrrolidone, etc.) ) Are mixed to prepare a negative electrode slurry. Hereinafter, the coating liquid containing the constituent material for forming the negative electrode active material layer 33 is referred to as a “negative electrode slurry”. The negative electrode active material layer 33 can be formed by applying this negative electrode slurry to the negative electrode side current collector sheet 32 and drying it.

In the structure shown in FIG. 1, the upper end surface of the negative electrode side separator layer 35 is located above the upper end surface of the positive electrode side separator layer 27, and the lower end surface of the negative electrode side separator layer 35 is located below the lower end surface of the positive electrode 21. Further, the upper end surface of the negative electrode active material layer 33 is located above the upper end surface of the positive electrode active material layer 26, and the lower end surface of the negative electrode active material layer 33 is located below the lower end surface of the positive electrode active material layer 26.
The negative electrode side separator layer 35 covering the negative electrode active material layer 33 and the positive electrode side separator layer 27 covering the positive electrode active material layer 26 separate the positive electrode 21 and the negative electrode 22.
It is preferable that the width of the negative electrode active material layer 33 (height in the vertical direction in FIG. 1) is formed wider than the width of the positive electrode active material layer 26. Further, in the cross section shown in FIG. 1, the upper end portion (upper end edge) of the negative electrode side separator layer 35 is preferably located above the upper end edge of the positive electrode active material layer 26, and the lower end portion of the negative electrode side separator layer 35 is the positive electrode. It is preferably located below the lower end of the active material layer 26. In other words, the upper end portion (upper end edge) of the negative electrode side separator layer 35 is preferably located outside the electrode laminate 3 than the upper end edge of the positive electrode active material layer 26, and the lower end portion of the negative electrode side separator layer 35 is the positive electrode active material layer 35. It is preferably located outside the electrode laminate 3 from the lower end of the material layer 26.

A positive electrode side conductive material 31 containing a carbon-based material is interposed between the bottom wall portion 11b of the positive electrode side container 11 and the positive electrode protruding portion 28 of the positive electrode 21. The positive electrode side conductive material 31 is a region (a region located inside the gasket 12) of the upper surface (contact surface) of the bottom wall portion 11b of the positive electrode side container 11 that faces the electrode laminated structure 3 in the axis O direction. ) Is formed in layers. The positive electrode 21 of the electrode laminated structure 3 is electrically connected to the positive electrode side container 11 via the positive electrode side conductive material 31.

On the other hand, a negative electrode side conductive material 36 made of the same material as the positive electrode side conductive material 31 described above is interposed between the top wall portion 13b of the negative electrode side container 13 and the negative electrode protruding portion 34 of the negative electrode 22. The negative electrode side conductive material 36 is layered over the entire surface of the lower surface of the top wall portion 13b in the negative electrode side container 13 facing the electrode laminated structure 3 in the axis O direction (the entire surface of the top wall portion 13b). It is formed. The negative electrode 22 of the electrode laminated structure 3 is electrically connected to the negative electrode side container 13 via the negative electrode side conductive material 36.

[Manufacturing method of secondary battery]
Next, a method of manufacturing the secondary battery 1 having the above-described configuration will be described.
In the following description, a method of manufacturing the positive electrode 21 and the negative electrode 22 will be described based on FIG. 3, a method of manufacturing the electrode laminated structure 3 will be described based on FIG. 2, and a positive electrode will be manufactured based on FIGS. 4 to 6. A method of connecting the positive electrode side container 11 and the negative electrode side container 13 by using the 21 and the negative electrode 22 will be mainly described.

As shown in FIG. 3 (A), on both the front and back surfaces of a strip-shaped negative electrode side current collector sheet 32 made of a metal foil such as copper foil and having a predetermined length, one side edge in the width direction (negative electrode in FIG. 3 (A)). The negative electrode slurry is applied and dried leaving a predetermined width (upper edge of the side current collector sheet 32) to form the negative electrode active material layer 33 (step of forming the negative electrode active material layer).
The negative electrode slurry contains the above-mentioned negative electrode active material, conductive auxiliary agent, binder, thickener and the like. The solvent of the slurry may be one that dissolves the binder and the thickener and disperses the active material and the conductive auxiliary agent.
Subsequently, a negative electrode side end insulating layer 40 made of an adhesive insulating tape or the like is formed on the front and back surfaces of both ends of the negative electrode side current collector sheet 32 in the length direction so as to cover each end with a predetermined width (negative electrode). Step of forming the side end insulating layer).

The negative electrode side end insulating layer 40 has a covering portion 40a that covers the end portion of the negative electrode side current collector sheet 32 and the end portion of the negative electrode active material layer 33 with a predetermined width, and also has the end face of the negative electrode side current collector sheet 32 and the negative electrode. It is provided with a negative electrode side extending portion 40b that covers the end surface of the active material layer 33 and further extends to the outside of the end portion of the negative electrode side current collector sheet 32. As shown in FIG. 3C, the negative electrode side end insulating layers 40 were attached to the front and back surfaces of the ends of the negative electrode side current collector sheet 32, respectively, and protruded from the lengthwise end of the negative electrode side current collector sheet 32. The negative electrode side extending portions 40b are bonded to each other. As a result, the end face of the negative electrode side current collector sheet 32 in the length direction and the end face of the negative electrode active material layer 33 in the length direction can be covered with the negative electrode side extending portion 40b.

When both ends of the negative electrode side current collector sheet 32 are individually covered with the negative electrode side end insulating layer 40, a paint for forming a separator layer is applied and cured as shown in FIG. 3 (B). The negative electrode side separator layer 35 is formed to form the negative electrode side winding electrode sheet 45. (Negative electrode side separator layer forming process)
When the paint is applied, the paint covers the surface of the negative electrode active material layer 33 existing between the negative electrode side end insulating layers 40 and 40 provided on the front and back surfaces of the negative electrode side current collector sheet 32. Further, the one side edge in the width direction (upper edge in FIG. 3A) 33a of each negative electrode active material layer 33 is applied so as to be covered with the paint in a predetermined width. Further, when the paint is applied so as to cover the surface of each negative electrode active material layer 33, the other side end face (lower end face in FIG. 3B) 33d in the width direction of each negative electrode active material layer 33 and the negative electrode side collection. The paint wraps around sufficiently to the other side end face (lower end face in FIG. 3B) in the width direction of the electric body sheet 32, and the paint applied from both the front and back surfaces is connected and applied so as to be integrated. To do.

When the paint for forming the separator layer is applied, it can be printed by a conventional method such as a screen printing method, a doctor blade method, an inkjet coating method, a spray coating method, a dipping method, or a die coating method. When applying by these printing methods, if a printing device having high printing accuracy is used, printing can be performed with high accuracy on the order of μm. Further, by these printing arrangements, it is possible to easily cause the paint to wrap around the end face side of the negative electrode side current collector sheet 32 and the end face side of the negative electrode active material layer 33.
As the paint, various paints described above can be used, but when a paint that cures by heat is used, it is heated to the curing temperature, and when a paint that cures by irradiation with light such as ultraviolet rays is used, it is for curing. In the case of a paint that is cured by irradiating light of a required wavelength with a required intensity and drying, the paint can be cured by drying at an appropriate temperature.

The main coating portion 35a can be formed by curing the paint covering the surface of the negative electrode active material layer 33, and the secondary coating portion 35a covering the one side edge 33a in the width direction of the negative electrode active material layer 33 with a predetermined width is cured. The covering portion 35b can be formed. Further, the connecting coating portion 35c can be formed by curing the paint covering the end surface 33d of the negative electrode active material layer 33 and the end surface of the negative electrode side current collector sheet 32.
As described above, the negative electrode side separator layer 35 having the main covering portion 35a, the sub covering portion 35b, and the connecting covering portion 35c can be formed, and the negative electrode side winding electrode sheet 45 shown in FIG. 3B can be obtained.

Next, as shown in FIG. 3 (D), one side edge in the width direction (FIG. 3 (D)) is formed on both the front and back surfaces of a strip-shaped positive electrode side current collector sheet 25 made of a metal foil such as an aluminum foil and having a predetermined length. ), The positive electrode side current collector sheet 25 (lower edge) is left with a predetermined width, and the positive electrode slurry is applied and dried to form the positive electrode active material layer 26. (Positive electrode active material layer forming process)
The positive electrode slurry contains the above-mentioned positive electrode active material, conductive auxiliary agent, binder, thickener and the like. The solvent of the slurry may be any solvent that dissolves the binder and the thickener and disperses the active material and the conductive auxiliary agent.
Subsequently, a positive electrode side end insulating layer 41 made of an adhesive insulating tape or the like is formed on the front and back surfaces of both ends of the positive electrode side current collector sheet 25 in the length direction so as to cover each end with a predetermined width. (Insulation layer forming step on the positive electrode side)

The positive electrode side end insulating layer 41 has a covering portion 41a that covers the end portion of the positive electrode side current collector sheet 25 and the end portion of the positive electrode active material layer 26 with a predetermined width, and also has the end face of the positive electrode side current collector sheet 25 and the positive electrode. It is provided with a positive electrode side extending portion 41b that covers the end surface of the active material layer 26 and further extends to the outside of the end portion of the positive electrode side current collector sheet 25.
As shown in FIG. 3D, the positive electrode side end insulating layers 41 were attached to the front and back surfaces of the ends of the positive electrode side current collector sheet 25, respectively, and protruded from the lengthwise end of the positive electrode side current collector sheet 25. The positive electrode side extending portions 41b are bonded to each other. As a result, the end face of the positive electrode side current collector sheet 25 in the length direction and the end face of the positive electrode active material layer 26 in the length direction can be covered with the positive electrode side extension portion 41b.

When both ends of the positive electrode side current collector sheet 25 are covered with the end insulating layers 41, a paint for forming a separator layer is applied and cured as shown in FIG. 3 (E) to form the positive electrode side separator layer 27. By doing so, the positive electrode side winding electrode sheet 46 can be obtained. (Positive electrode side separator layer forming step)
When applying the paint, the paint is applied so as to cover the surface of the positive electrode active material layer 26 existing between the positive electrode side end insulating layers 41 and 41 provided on the front and back surfaces of the positive electrode side current collector sheet 25. When the paint is applied so as to cover the surface of each positive electrode active material layer 26, one side end surface (upper end surface in FIG. 3 (E)) 26d in the width direction of each positive electrode active material layer 26 and the positive electrode side current collection. The paint is sufficiently wrapped around one side end surface in the width direction of the body sheet 25 (the upper end surface in FIG. 3E), and the paints applied from both the front and back surfaces are connected and applied so as to be integrated. Further, the other side edge (lower end edge in FIG. 3E) 26a in the width direction of each positive electrode active material layer 26 is coated with a predetermined width so as to be covered with the paint.
To apply the paint, a general printing method similar to the case where the paint is applied to the negative electrode side current collector sheet 32 can be used.

The main coating portion 27a can be formed by curing the paint covering the surface of the positive electrode active material layer 26, and the secondary coating portion 27a covering the one side edge 26a in the width direction of the positive electrode active material layer 26 with a predetermined width is cured. The covering portion 27b can be formed. Further, the connecting coating portion 27c can be formed by curing the paint covering the end face of the positive electrode active material layer 26 and the end face of the negative electrode side current collector sheet 32.
As described above, the positive electrode side separator layer 27 having the main covering portion 27a, the sub covering portion 27b, and the connecting covering portion 27c can be formed, and the positive electrode side winding electrode sheet 46 shown in FIG. 3 (E) can be obtained.

A negative electrode side winding electrode sheet 45 with a separator layer whose both ends are covered with a negative electrode side end insulating layer 40, and a positive electrode side winding electrode with a separator layer whose both ends are covered with a positive electrode side end insulating layer 41. After the sheet 46 is produced, the electrode laminated structure 3 is formed by the procedure described below based on FIG.
Specifically, a laminate is formed in which the negative electrode side winding electrode sheet 45 and the positive electrode side winding electrode sheet 46 are laminated in this order. This laminated body is a laminated body in which the negative electrode side winding electrode sheet 45 and the positive electrode side winding electrode sheet 46 are slightly displaced in the width direction (axis O direction) thereof. In this laminated body, the negative electrode protruding portion 34 is projected on one side in the width direction, and the positive electrode protruding portion 28 is projected on the other side in the width direction.
The spiral electrode laminated structure 3 shown in FIG. 1 can be obtained by winding the laminated body around the winding core 50 shown in FIG. 2 with the negative electrode side on the inside and the positive electrode side on the outside using a winding device. It can be done (electrode laminated structure manufacturing process: winding process).
When the negative electrode side winding electrode sheet 45 and the positive electrode side winding electrode sheet 46 are laminated and wound by the winding device, the negative electrode side winding electrode sheet 45 and the positive electrode side winding electrode sheet 46 are combined. It may be wound while laminating.

Next, as shown in FIG. 4, the gasket 12 is set in the peripheral wall portion 11a of the positive electrode side container 11 (gasket arrangement step).
Subsequently, as shown in FIG. 5, a paste-like thermosetting positive electrode side conductive material 51 is applied to a region located inside the gasket 12 on the bottom wall portion 11b of the positive electrode side container 11 (conductive material coating). Process).
In the coating step, the positive electrode side conductive material 51 may be coated on a predetermined region on the bottom wall portion 11b by pad printing or the like.

Next, as shown in FIG. 6, the previously manufactured electrode laminated structure 3 is set in the positive electrode side container 11 (setting step).
Specifically, the electrode laminated structure 3 and the positive electrode side container 11 are relative to the axis O direction in a state where the positive electrode protruding portion 28 of the electrode laminated structure 3 and the positive electrode side container 11 are opposed to each other in the axis O direction. The lower end surface of the positive electrode protruding portion 28 is pressed against the positive electrode side conductive material 51 to bring them into contact with each other.
Then, in a state where the lower end surface of the positive electrode protruding portion 28 is in contact with the positive electrode side conductive material 51, the positive electrode side conductive material 51 is heated and cured (curing step: positive electrode side connecting step).
By this step, the positive electrode protruding portion 28 can be electrically bonded to the positive electrode side container 11 via the positive electrode side conductive material 31. Prior to the setting step, the negative electrode side conductive material 52 was applied in advance on the upper end surface of the negative electrode side projecting portion 34 (the contact surface of the negative electrode side container 13 with the top wall portion 13b), and the negative electrode side container 13 was brought into contact with the negative electrode side container 13. After that, in the curing step described above, the negative electrode side conductive material 52 may be cured together with the positive electrode side conductive material 51.

Further, the negative electrode side conductive material 52 is applied onto the top wall portion 13b of the negative electrode side container 13 by the same method as the above-mentioned coating step, and then the conductive material is heated and cured (negative electrode side connection step).
By this step, the negative electrode side conductive material 36 is formed on the top wall portion 13b of the negative electrode side container 13. Before the negative electrode connection step, the electrolytic solution is injected into the positive electrode side container 11 in advance.

Finally, the negative electrode side container 13 is fixed to the positive electrode side container 11. Specifically, after inserting the peripheral wall portion 13a of the negative electrode side container 13 into the groove portion 14 of the gasket 12, the peripheral wall portion 11a of the positive electrode side container 11 is caulked inward in the radial direction.
As a result, the negative electrode side container 13 can be fixed to the positive electrode side container 11, and the above-mentioned secondary battery 1 is completed.

In the secondary battery 1 described above, since the positive electrode side conductive material 31 containing a carbon-based material is interposed between the positive electrode protruding portion 28 and the positive electrode side container 11, the positive electrode protruding portion 28 and the positive electrode side container 11 are simply separated. Compared with the case of connecting in contact with each other, electrical reliability can be ensured and high-rate charge / discharge characteristics can be improved.
Further, since the configuration is such that the positive electrode side conductive material 31 and the positive electrode protruding portion 28 are only brought into contact with each other, the configuration is simpler than, for example, a configuration in which a tab separate from the positive electrode 21 is connected to the positive electrode side container 11 by welding or the like. Electrical reliability can be ensured after reducing manufacturing man-hours and manufacturing costs.

In the secondary battery 1 of the present embodiment, since the negative electrode protruding portion 34 and the negative electrode side container 13 are also electrically and securely connected by the negative electrode side conductive material 36, further electrical reliability can be ensured.
Further, since it is not necessary to provide a connection space such as a tab required in the conventional structure on the negative electrode side current collector sheet 32, the contact surface of the negative electrode 22 with the negative electrode side container 13 (top wall portion 13b of the negative electrode side container 13). ), The negative electrode active material layer 33 can be arranged.
Therefore, while maintaining the volume of the exterior body 2, the area of the negative electrode active material layer 33 can be secured, and the area of the overlapping portion of the positive electrode 21 and the negative electrode 22 can be secured, so that the volumetric efficiency of the secondary battery 1 can be improved. Can be planned.

In the method for manufacturing the secondary battery 1 of the present embodiment, the positive electrode side conductivity is held in a state where the positive electrode side projecting portion 2 is in contact with the paste-like positive electrode side conductive material 51 applied to the positive electrode side container 11 (bottom wall portion 11b). The structure is such that the material 51 is cured. According to this configuration, both the positioning of the electrode laminated structure 3 with respect to the positive electrode side container 11 and the connection between the positive electrode protruding portion 28 and the positive electrode side conductive material 31 can be performed at once, so that the manufacturing man-hours can be reduced. Electrical reliability can be ensured while reducing manufacturing costs.

In the secondary battery 1 of the present embodiment, the positive electrode side current collector sheet 25 and the positive electrode active material layer 26 are coated with a coating film for forming a separator layer and cured to form the positive electrode separator layer 27. The positive electrode separator layer 27 can be brought into close contact with the positive electrode side current collector sheet 25 and the positive electrode active material layer 26. Further, since the negative electrode side current collector sheet 32 and the negative electrode active material layer 33 are coated with a coating film for forming a separator layer and cured to form the negative electrode separator layer 35, the negative electrode side current collector sheet 32 is formed. The negative electrode separator layer 35 can be brought into close contact with the negative electrode active material layer 33.
Therefore, when the positive electrode 21 and the negative electrode 22 are wound to form the electrode laminated structure 3, the insulation between the positive electrode 21 and the negative electrode 22 can be ensured even if the positive electrode 21 and the negative electrode 22 are disturbed. Therefore, it is possible to obtain the electrode laminated structure 3 in which the risk of short circuit does not occur. In this respect, in the case of the conventional structure in which the positive electrode and the negative electrode are wound via the sheet-shaped separator, if the positive electrode and the negative electrode or the separator are disturbed, a short-circuit risk occurs.

In the secondary battery 1 of the present embodiment, the coating accuracy of the coating film on the positive electrode side current collector sheet 25 can be controlled by a general coating device with an error of about ± 10 μm, and the negative electrode side current collection The coating accuracy of the coating film on the body sheet 32 can be controlled within ± 10 μm by a general coating device. Therefore, the length of the positive electrode protruding portion 28 provided on the positive electrode 21 and the length of the negative electrode protruding portion 34 provided on the negative electrode 22 can be formed with an accuracy of about ± 10 μm. Therefore, the positive electrode protruding portion 28 having a specified length can be brought into contact with the conductive material 31, and the negative electrode protruding portion 34 having a specified length can be brought into contact with the conductive material 36, and electricity between the positive electrode side container 11 and the positive electrode 21 can be obtained. It is possible to make good contact with the target and electrical contact between the negative electrode side container 13 and the negative electrode 22.
In this respect, in the case of the conventional structure in which the positive electrode and the negative electrode are wound via the sheet-shaped separator, the winding disorder of the separator becomes large, and when a part of the separator is displaced to the vicinity of the negative electrode protruding portion or the tip of the positive electrode protruding portion, The electrical contact between the negative electrode side container or the positive electrode side container and the electrode may be insufficient.

In the secondary battery 1 of the present embodiment, the negative electrode side separator layer 35 is provided with the auxiliary coating portion 35b to cover the one side edge in the width direction of the negative electrode active material layer 33, and the connecting coating portion 35c is provided. It covers the other side edge of the negative electrode active material layer 33 in the width direction. Therefore, the insulating property of both side edges in the width direction of the negative electrode active material layer 33 is ensured. Further, the positive electrode side separator layer 27 is provided with the auxiliary coating portion 27b to cover one side edge in the width direction of the positive electrode active material layer 26, and the connecting coating portion 27c is provided to cover the other side end in the width direction of the positive electrode active material layer 26. It covers the edge. Therefore, the insulating property of both side edges in the width direction of the positive electrode active material layer 26 is ensured.
In addition to these, in the negative electrode 22, both ends in the length direction are covered with the end insulating layer 40 to ensure insulation on both ends, and in the positive electrode 21, both ends in the length direction are covered with the end insulating layer 41. Insulation at both ends is ensured.
Together, these provide the negative electrode side separator layer 35 and the end insulating layer 40 to ensure the insulation of the negative electrode 22, and the positive electrode side separator layer 27 and the end insulating layer 41 to insulate the positive electrode 21. Sex can be secured.

By the way, in the above-described embodiment, the configuration in which the electrode laminated structure 3 and the negative electrode side container 13 are assembled to the positive electrode side container 11 in which the gasket 12 is set has been described, but the present invention is not limited to this configuration.
For example, the electrode laminated structure 3 and the positive electrode side container 11 may be assembled to the negative electrode side container 13 in which the gasket 12 is set by using the same method as the above-mentioned manufacturing method.
Specifically, first, in the negative electrode side container 13 in which the gasket 12 is set, the negative electrode side conductive material 52 is applied onto the top wall portion 13b (coating step), and then the negative electrode side protruding portion 34 comes into contact with the conductive material. , The electrode laminated structure 3 is set in the negative electrode side container 13 (setting step).
Then, with the negative electrode protruding portion 34 in contact with the conductive material, the negative electrode side conductive material 52 is cured (curing step), and the electrolytic solution is injected into the negative electrode side container 13. Then, using the positive electrode side container 11 in which the positive electrode side conductive material 31 is previously formed on the bottom wall portion 11b, the positive electrode side container 11 is externally inserted into the gasket 12, and then the peripheral wall portion 11a of the positive electrode side container 11 is radially inside. The secondary battery 1 can be manufactured by caulking toward.

Also in this manufacturing method, since the negative electrode side conductive material 52 is cured in a state where the negative electrode side conductive material 52 is in contact with the paste-like negative electrode side conductive material 52, the electrode laminated structure 3 is positioned with respect to the negative electrode side container 13. Both the negative electrode protruding portion 34 and the negative electrode side conductive material 36 can be connected at once. Prior to the setting step, the positive electrode side conductive material 51 to be the positive electrode side conductive material 31 is applied in advance on the contact surface of the positive electrode side container 11 with the bottom wall portion 11b of the positive electrode side protruding portion 28, and the negative electrode side negative electrode is applied in the curing step. It may be cured together with the negative electrode side conductive material 52 on the 22 side.

Further, in the structure shown in FIG. 1, the upper end portion (upper end edge) of the negative electrode side separator layer 35 is above the upper end edge of the positive electrode active material layer 26, and the lower end portion (lower end edge) of the negative electrode side separator layer 35 is positive electrode active. It is arranged below the lower edge of the material layer 26.
When the positive electrode 21 and the negative electrode 22 are wound to form the electrode laminated structure 3, the positive electrode active material layer 26 is wound so as to be within the width of the negative electrode side separator layer 35, although some winding disorder occurs. Therefore, the battery 1 having a desirable positive electrode arrangement can be provided.
The width (vertical width) of the negative electrode active material layer 33 is larger than the width (vertical width) of the positive electrode active material layer 26 shown in FIG. 1, and the width of the negative electrode side separator 35 is larger than the width of the positive electrode active material layer 26. Is made even larger. Therefore, the positive electrode 21 and the negative electrode 22 can be wound so that the positive electrode active material layer 26 is contained within the vertical width of the negative electrode side separator 35 in anticipation of a large width. With the above configuration, the target battery 1 can be obtained even if some winding disorder occurs.

<Second Embodiment>
FIG. 7 shows the secondary battery of the second embodiment according to the present invention, and the secondary battery (electrochemical cell) 60 of the second embodiment is the secondary battery 1 of the first embodiment on the positive electrode 21 side. The structure has an electrode laminated structure 61 in which the separator layer 27 provided in the above is omitted. Other structures are the same as those of the secondary battery 1 of the first embodiment.

In this second embodiment, the electrode laminated structure 61 includes the negative electrode side winding electrode sheet 45 shown in FIG. 3B, the positive electrode active material layer 26 shown in FIG. 3D, and the positive electrode side end insulating layer 41. , 41 is configured by winding a positive electrode side current collector sheet 25.

In the secondary battery 1 shown in FIG. 1, since the coating film curing type separator layer is provided on both the positive electrode 21 and the negative electrode 22, the occurrence of short-circuit risk can be made lower than that of the secondary battery 60 of the second embodiment. it can. However, even in the secondary battery 60 shown in FIG. 7, the negative electrode side current collector sheet 32 and the negative electrode active material layer 33 are covered with the negative electrode side separator layer 35, and the negative electrode side current collector sheet 32 and the end face in the length direction. Since the end face of the negative electrode active material layer 33 in the length direction is covered with the end insulating layers 40 and 41, the occurrence of short-circuit risk can be sufficiently reduced.

In the secondary battery 60 shown in FIG. 7, since the separator layer 27 on the positive electrode 21 side is omitted, when the electrode laminated structure 61 is formed, the separator layer 27 is produced with the same outer diameter as the electrode laminated structure 3. By the amount omitted, the positive electrode 21 and the negative electrode 22 can be wound and incorporated more.
Therefore, the secondary battery 60 is a secondary battery having a higher volume efficiency as a battery than the secondary battery 1 and a high battery capacity density per volume.
The secondary battery 60 of the second embodiment has the same configuration as the secondary battery 1 of the first embodiment except for the configuration in which the separator layer 27 is omitted. Therefore, regarding other functions and effects, the second embodiment of the first embodiment The same effect as that of the next battery 1 can be obtained.

When the secondary battery 60 of the second embodiment is manufactured, the negative electrode side winding electrode sheet 45 shown in FIG. 3 (B) and the positive electrode side current collection in the state where the separator layer is not formed shown in FIG. 3 (D). The electrode laminated structure 60 can be manufactured by using the body sheet 32, laminating with a slight shift in the width direction as in the case shown in FIG. 2, and winding with the winding core 50.
In the electrode laminated structure 60, the structure in which the positive electrode protruding portion 28 is projected on one side of the end surface and the negative electrode protruding portion 34 is projected on the other side is the same structure as the electrode laminated structure 3 of the first embodiment. Therefore, the point that the electrode laminated structure 60 can be accommodated in the accommodation space S composed of the positive electrode side container 11 and the negative electrode side container 13 is the same. Similarly, the negative electrode protruding portion 34 can be connected to the negative electrode side container 13 via the conductive material 36, and the positive electrode protruding portion 28 can be connected to the positive electrode side container 11 via the conductive material 31.

FIG. 8 is a plan view showing an example configuration of an electrode sheet for continuous winding on the negative electrode side, which is suitable for mass production of the secondary batteries of the first embodiment or the second embodiment.
For example, in the case of mass-producing the secondary battery 1, it is necessary to continuously manufacture a plurality of electrode laminated structures 3. In this case, the negative electrode side winding electrode sheet 45 shown in FIG. 3 (B) and the positive electrode side winding electrode sheet 46 shown in FIG. 3 (E) can be continuously supplied to the winding device and wound. preferable.

The negative electrode side continuous winding electrode sheet 65 shown in FIG. 8 has a configuration in which a plurality of negative electrode side winding electrode sheets 45 shown in FIG. 3B are linearly connected in a row. In the negative electrode side continuous winding electrode sheet 65, the end insulating layer 40 formed at the end of the negative electrode side winding electrode sheet 45 shown in FIG. 3B is formed of an insulating tape, and the adjacent negative electrode side It is configured by connecting a plurality of ends of the current collector sheet 32 to each other via an end insulating layer 40.

In the negative electrode side continuous winding electrode sheet 65 shown in FIG. 8, when the end insulating layer 40 connecting the adjacent negative electrode side current collector sheet 32 is cut at the center portion in the width direction, it is shown in FIG. 3 (B). An electrode sheet 45 for winding on the negative electrode side is obtained.
Although not shown, an electrode sheet for continuous winding on the positive electrode side is prepared in which the positive electrode side winding sheet 46 shown in FIG. 3 (E) is linearly connected in a plurality of rows with an end insulating layer 41 made of insulating tape. To do.
In this positive electrode side continuous winding electrode sheet, when the end insulating layer connecting the adjacent positive electrode side current collector sheets is cut at the center portion in the width direction, the negative electrode side winding electrode shown in FIG. 3 (E). A sheet is obtained.

When the negative electrode side continuous winding electrode sheet 65 shown in FIG. 8 and the positive electrode side continuous winding electrode sheet (not shown) are cut out at the end insulating layer, the negative electrode side winding electrode sheet 45 and the positive electrode side winding are used. The electrode sheet 46 can be obtained. The electrode laminated structure 3 can be formed by laminating these separated electrode sheets and supplying them to the winding device.
After forming one electrode laminated structure 3, the electrode sheet 65 for continuous winding on the negative electrode side and the electrode sheet for continuous winding on the positive electrode side (not shown) are separated from each other at the end insulating layer, and the negative electrode side winding is performed. A further electrode laminated structure 3 can be formed by obtaining the electrode sheet 45 for winding and the electrode sheet 46 for winding on the positive electrode side, laminating them, and supplying them to the winding device.
By repeating the above operation, the electrode laminated structure 3 can be continuously manufactured.

By using the negative electrode side continuous winding electrode sheet 65 shown in FIG. 8 and the positive electrode side continuous winding electrode sheet (not shown), the negative electrode side and positive electrode winding electrode sheets for the negative electrode and the positive electrode are continuously produced in the case of mass production. It can be supplied to the winding device.
The negative electrode side continuous winding electrode sheet 65 shown in FIG. 8 and the positive electrode side continuous winding electrode sheet (not shown) can be wound around a bobbin or the like for storage, and can be unwound and used as needed. When used in this way, a large amount of winding electrode sheets can be stored in a narrow space, and the installation space when unwound and used can be reduced. Therefore, when the electrode laminated structure 3 is mass-produced, it can be produced in a small space.

1 ... Secondary battery (electrochemical cell), 2 ... Exterior body, 3 ... Electrode laminated structure, 11 ... Positive electrode side container, 11b ... Bottom wall part, 12 ... Gasket, 13 ... Negative electrode side container, 13b ... Top wall part , 21 ... Positive electrode, 22 ... Negative electrode, 25 ... Positive electrode side current collector sheet, 26 ... Positive electrode active material layer, 27 ... Positive electrode side separator layer, 27a ... Main coating part, 27b ... Secondary coating part, 27c ... Connecting coating part, 28 ... Positive electrode protrusion,
31 ... Positive electrode side conductive material, 32 ... Negative electrode side current collector sheet, 33 ... Negative electrode active material layer, 34 ... Negative electrode protruding part, 35 ... Negative electrode side separator layer, 35a ... Main coating part, 35b ... Sub-coating part, 35c ... Connecting coating part, 36 ... Negative electrode side conductive material, 40 ... Negative electrode side end insulating layer, 40b ... Negative electrode side extending part,
41 ... Positive electrode side end insulating layer, 41b ... Positive electrode side extension, 45 ... Negative electrode side winding electrode sheet,
46 ... Positive electrode side winding electrode sheet, 50 ... Winding core, 51 ... Positive electrode side conductive material, 52 ... Negative electrode side conductive material, 60 ... Secondary battery (electrochemical cell), 65 ... Negative electrode side continuous winding electrode sheet , S ... Storage space.

Claims (13)

It has a band-shaped positive electrode and a band-shaped negative electrode.
A separator layer composed of a coating film cured layer formed on both front and back surfaces of at least one of the positive electrode and the negative electrode excluding at least one side edge in the width direction or the other side edge in the width direction of the positive electrode and the negative electrode is interposed. , The positive electrode and the negative electrode are laminated by shifting the edge on one side in the width direction and the edge on the other side by a predetermined width in the width direction, and the laminated body is wound so as to orbit an arbitrary winding center axis. The constructed electrode laminated structure and
A positive electrode side container in which a positive electrode projecting portion that protrudes outward from one side edge of the negative electrode adjacent to the edge is electrically connected to the edge of the wound positive electrode on one side in the width direction.
A negative electrode projecting portion that protrudes outward from the other side edge of the positive electrode adjacent to the edge is electrically connected to the other edge of the wound negative electrode in the width direction, and the electrode is laminated together with the positive electrode side container. The negative electrode side container that defines the storage space for storing the structure,
An electrochemical cell characterized by being equipped with. The band-shaped positive electrode is configured to include a band-shaped positive electrode side current collector sheet and a positive electrode active material layer formed on both front and back surfaces of the current collector sheet except for the positive electrode protrusion.
The band-shaped negative electrode is configured to include a band-shaped negative electrode side current collector sheet and a negative electrode active material layer formed on both front and back surfaces of the current collector sheet except for the negative electrode protrusion.
An insulating layer at the end of the positive electrode is formed to cover the front and back surfaces of the edge on both ends in the length direction of the positive electrode with a predetermined width.
The electrochemical cell according to claim 1, wherein a negative electrode side end insulating layer is formed so as to cover the front and back surfaces of the end edges on both ends in the length direction of the negative electrode with a predetermined width. Separator layers covering the negative electrode active material layer are formed on both the front and back surfaces of the negative electrode, and the separator layer located on one side edge in the width direction of the separator layer located near the protruding portion of the negative electrode and the separator located on the other side in the width direction of the negative electrode. The electricity according to claim 2, wherein the other side edges of the layers all project outward from the widthwise edge of the positive electrode active material layer adjacent thereto in the electrode laminated structure. Chemical cell. The positive electrode side end insulating layer is formed with a positive electrode side extending portion covering the length direction end side end surface of the positive electrode, and the negative electrode side end insulating layer is a negative electrode covering the negative electrode side end face in the length direction. The electrochemical cell according to claim 2 or 3, wherein a side extension portion is formed. The electrochemical cell according to any one of claims 1 to 4, wherein the positive electrode side container and the positive electrode protruding portion are electrically connected via a conductive material. The electrochemical cell according to any one of claims 1 to 5, wherein the negative electrode side container and the negative electrode protruding portion are electrically connected via a conductive material. The electrochemical cell according to any one of claims 1 to 6, wherein the positive electrode side end insulating layer and the negative electrode side end insulating layer are made of an insulating tape. The method for producing an electrochemical cell according to any one of claims 1 to 7.
A step of forming a positive electrode side end insulating layer on the front and back surfaces of both ends of a strip-shaped positive electrode, and a step of forming a negative electrode side end insulating layer on both front and back surfaces of a strip-shaped negative electrode.
An insulating coating film is formed on at least one of the positive electrode side current collector sheet and the negative electrode side current collector sheet on which the end insulating layer is formed, except for the one side edge in the width direction of the front and back surfaces of the sheet. Process and
The step of curing the insulating coating film to form a separator layer and
The negative electrode side current collector sheet and the positive electrode side current collector sheet are overlapped with each other via the separator layer by shifting one side edge in the width direction and the other side edge in the width direction by a predetermined width in the width direction. The process of forming a wound electrode laminated structure along an arbitrary winding center axis, and
A negative electrode side connecting step of electrically connecting a negative electrode protruding portion formed by projecting one side edge of the negative electrode side current collector sheet to one side end surface of the electrode laminated structure by the winding to the negative electrode side container.
A positive electrode side connecting step is provided in which a positive electrode protruding portion formed by projecting the other side edge of the positive electrode side current collector sheet to the other side end surface of the electrode laminated structure by the winding is electrically connected to the positive electrode side container. A method for manufacturing an electrochemical cell, which is characterized in that. A negative electrode having a negative electrode active material layer formed on a portion other than the negative electrode side current collector sheet and one side edge thereof is used as the negative electrode, and the positive electrode side current collector sheet and other side edge edges are used as the positive electrode. Using a positive electrode having a positive electrode active material layer formed on the part to be removed,
The negative electrode side end insulating layer covers both the front and back surfaces of the negative electrode side current collector sheet and the negative electrode active material layer located at both ends, and the positive electrode side end insulating layer covers the positive electrode side current collector sheet. The method for producing an electrochemical cell according to claim 8, wherein both ends of the front and back surfaces of the above and the positive electrode active material layer located at both ends are covered. According to claim 8 or 9, when the positive electrode protruding portion is electrically connected to the positive electrode side container, the positive electrode side container is connected via a paste-like positive electrode side conductive material coated on the inner surface of the positive electrode side container. The method for producing an electrochemical cell according to the description. Claims 8 to 10, wherein when the negative electrode protruding portion is electrically connected to the negative electrode side container, the negative electrode side container is connected via a paste-like negative electrode side conductive material coated on the inner surface of the negative electrode side container. The method for producing an electrochemical cell according to any one. The positive electrode side end insulating layer formed on the positive electrode side current collector sheet is formed by attaching an insulating tape, and the negative electrode side end insulating layer formed on the negative electrode side current collector sheet is attached with an insulating tape. The method for producing an electrochemical cell according to any one of claims 8 to 11, wherein the electrochemical cell is formed by. A plurality of positive electrode side current collector sheets are connected in a band shape in a straight line via the positive electrode side end insulating layer, and a plurality of negative electrode side current collector sheets are connected in a band shape in a straight line through the negative electrode side end insulating layer. Any one of claims 8 to 12, characterized in that the plurality of positive electrode side current collector sheets connected and connected to the negative electrode side current collector sheets are individually and sequentially provided to the winding step. The method for manufacturing an electrochemical cell described in 1.

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