JP7646345B2 - Battery element roll, its manufacturing method and battery including said roll - Google Patents

Description

The present invention relates to a roll of battery elements and a manufacturing method thereof, as well as a battery using such a roll.

In a typical lithium-ion battery manufacturing method, a positive electrode is first prepared by coating and drying a solution of a positive electrode active material such as lithium cobalt oxide on both sides of a positive electrode collector such as aluminum foil, and then coating and drying a solution of a negative electrode active material such as a carbon material on a negative electrode collector such as copper foil. At this time, the electrode materials for the positive and negative electrodes are manufactured in the form of long strips. Next, a porous separator film that allows ions to move is sandwiched between the negative electrodes, and the positive electrodes, negative electrodes, and separator films are rolled up so that they are overlapping in several layers, and then the battery is placed in a battery case, the electrolyte is injected, and the case is sealed.

Patent Document 1 discloses a method for manufacturing a lithium-ion secondary battery in which an electrode plate group, in which positive and negative electrode plates are wound with a separator between them, is placed in the battery case from the open end of the battery case, an electrolyte is injected, and then the open end of the battery case is sealed.

Patent Document 2 discloses a method for manufacturing a thin battery in which a battery body consisting of a laminate in which positive and negative electrodes are laminated with a separator therebetween or a wound laminate and a plurality of leads respectively joined to the positive and negative electrodes is housed in a flexible package and sealed, the method comprising the steps of housing the battery body in the package and injecting an electrolyte, and subsequently reducing the pressure of the package to a pressure lower than atmospheric pressure and equal to or higher than the vapor pressure of the electrolyte, and sealing the package.

JP 2000-90974 A Republished WO00/41263

The present invention aims to provide a roll of battery elements that can be easily and mass-produced without the need for a liquid injection process to inject an electrolyte, a method for manufacturing the same, and a battery that uses such a roll.

The present invention provides a rolled battery element, which is formed by winding up a negative electrode sheet having a negative electrode current collector layer and a negative electrode active layer containing at least a negative electrode active material and an electrolyte solution provided in this order on a first long resin sheet, and a positive electrode sheet having a positive electrode current collector layer and a positive electrode active layer containing at least a positive electrode active material and an electrolyte solution provided in this order on a second long resin sheet, with the negative electrode active layer and the positive electrode active layer facing each other with a separator film sandwiched between them.
The electrolyte solution contained in the negative electrode active layer and the electrolyte solution contained in the positive electrode active layer may be the same or different.

In the roll of the battery element according to the present invention, the negative electrode sheet and the positive electrode sheet are wound so that the surface of the first long resin sheet on which the negative electrode collector layer and the negative electrode active layer are provided faces the surface of the second long resin sheet on which the positive electrode collector layer and the positive electrode active layer are provided, and the separator film is sandwiched between the negative electrode active layer and the positive electrode active layer. Therefore, the area sandwiched between the resin sheets of the negative electrode sheet and the positive electrode sheet has a laminated structure in which the negative electrode collector layer, the negative electrode active layer, the separator film, the positive electrode active layer, and the positive electrode collector layer are laminated in sequence, and this laminated structure is electrically insulated by the resin sheet to form a roll of the battery element wound in large numbers.

In the roll body according to the present invention, at least one of the negative electrode active layer and the positive electrode active layer may contain a gelling agent.
The positive electrode active layer and the negative electrode active layer provided on the long resin sheet contain electrode active material particles and an electrolyte, and are in a semi-solid state, which is a mixture of a liquid phase and a solid phase, such as a particle suspension, a colloidal suspension, an emulsion, a gel, or a micelle. Therefore, in the process of forming the electrode active layer on the resin sheet, there may be cases where the liquid leaks or the shape is difficult to maintain.
According to the present invention, by adding a gelling agent to the electrode active layer, it is possible to easily fix the electrode active layer onto the resin sheet while maintaining its fluidity.
When both the negative electrode active layer and the positive electrode active layer contain a gelling agent, the gelling agents contained in these layers may be the same or different.

The gelling agent can be at least one selected from the group consisting of crosslinkable polymers, polymeric gelling agents, low molecular weight gelling agents, and solid fine particles.
In the roll body according to the present invention, when solid fine particles are used as a gelling agent, the solid fine particles can be conductive fine particles.

The roll body according to the present invention may be provided with a negative electrode current collector exposed portion where the negative electrode current collector layer is exposed, and a positive electrode current collector exposed portion where the positive electrode current collector layer is exposed.
In this case, by connecting a negative electrode lead to the exposed portion of the negative electrode current collector and a positive electrode lead to the exposed portion of the positive electrode current collector, electrical connection with other electric components and the like can be achieved.
The battery according to the present invention may be a battery in which the roll body is housed in a battery case.

The present invention relates to a process for preparing a negative electrode roll-shaped original sheet by winding a negative electrode sheet having a negative electrode current collector layer and a negative electrode active layer containing at least a negative electrode active material and an electrolyte solution on a first surface of a wide and long first resin sheet, a process for preparing a positive electrode roll-shaped original sheet by winding a positive electrode sheet having a positive electrode current collector layer and a positive electrode active layer containing at least a positive electrode active material and an electrolyte solution on a first surface of a wide and long second resin sheet, a process for preparing a wide and long roll-shaped separator film, and a process for preparing the negative ... The method for manufacturing a roll of battery elements includes a slitting process in which the negative electrode sheet unwound from a reel and the positive electrode sheet unwound from the positive electrode roll are overlapped so that they face each other with a separator film between the negative electrode active layer and the positive electrode active layer, and the negative electrode sheet, the separator film, and the positive electrode sheet are overlapped and slit into multiple narrow sheets; and a winding process in which the multiple narrow sheets are each wound into a roll to form a roll of battery elements.

The manufacturing method of the present invention makes it possible to efficiently mass-produce rolls of battery elements of any size, in which a laminate structure in which a negative electrode collector layer, a negative electrode active layer, a separator film, a positive electrode active layer, and a positive electrode collector layer are sequentially laminated with a resin sheet interposed therebetween, is wound up in large numbers.

In the manufacturing method of the present invention, the slitting step involves cutting the negative electrode sheet unwound from the negative electrode roll, the positive electrode sheet unwound from the positive electrode roll, and the separator film unwound from the roll-shaped separator film into the multiple narrow-width sheets by a slitter head in a state in which the negative electrode sheet and the positive electrode active layer are overlapped so as to face each other with the separator film sandwiched between them, and in the winding step, the end of the narrow-width sheet can be cut when it has been wound up a predetermined number of times or to a predetermined diameter.
This makes it possible to manufacture a roll of battery elements that matches any desired battery capacity.

In the manufacturing method of the present invention, the step of preparing the negative electrode roll-shaped original sheet may include coating the negative electrode current collector layer and the negative electrode active layer in this order on the wide and long first resin sheet, and the step of preparing the positive electrode roll-shaped original sheet may include coating the positive electrode current collector layer and the positive electrode active layer in this order on the wide and long second resin sheet.
In the coating method, the paste (coating liquid) for each layer can be applied in sequence onto a resin sheet to form a laminate, so there are fewer restrictions on the coating width and length, making it suitable for mass production of the same laminate structure.
The fluid semi-solid electrode active layer is suitable for coating by supplying it onto a resin sheet from a nozzle or the like. If necessary, the electrode active layer can be fixed onto the resin sheet by photopolymerization, plasticization, or gelation, and the layer fluidized by high-temperature heating can also be fixed at ambient temperature. The electrode active layer may also be fixed by lowering the temperature to a temperature below the freezing point of the electrolyte.

The manufacturing method of the present invention can further include a step of forming a negative electrode current collector exposed portion where the negative electrode current collector layer is exposed, and a positive electrode current collector exposed portion where the positive electrode current collector layer is exposed, on at least a part of the roll body, typically on the outermost peripheral surface and the innermost peripheral surface.
In this case, by connecting a negative electrode lead to the negative electrode current collector exposed portion and a positive electrode lead to the positive electrode current collector exposed portion, electrical connection with other electric components and the like can be achieved.

The present invention makes it possible to efficiently mass-produce rolls of battery elements of any size, in which a multiplicity of laminated structures each having a negative electrode current collector layer, a negative electrode active layer, a separator film, a positive electrode active layer, and a positive electrode current collector layer sequentially laminated with a resin sheet interposed therebetween are wound up.
In addition, by sequentially applying the paste (coating liquid) for each layer onto a resin sheet and drying it to form a laminate, there are fewer restrictions on the coating width and length, making it suitable for mass production of the same laminate structure.

1A and 1B are schematic diagrams of a roll body according to one embodiment of the present invention, in which FIG. 1A is a diagram showing the entire roll body, and FIG. 1B is a diagram showing a cross-sectional layered structure of the roll body. FIG. 1 is a process flow diagram illustrating one embodiment of a manufacturing method of the present invention. 1A and 1B are schematic diagrams for explaining a slitting step in one embodiment of a manufacturing method of the present invention, in which (a) is a perspective view and (b) is a side view. 1A and 1B are schematic diagrams showing cross-sectional stacking configurations of a negative electrode sheet and a positive electrode sheet in one embodiment of the manufacturing method of the present invention, in which (a) is a diagram showing a state in which a negative electrode sheet, a positive electrode sheet, and a separator film are prepared, (b) is a diagram showing a state in which a negative electrode sheet, a positive electrode sheet, and a separator film are stacked, and (c) is a diagram showing a state in which a plurality of negative electrode sheets, positive electrode sheets, and separator films are stacked. FIG. 2 is a schematic diagram showing a cross-sectional laminate structure when a current collector exposed portion is formed in one embodiment of the manufacturing method of the present invention. FIG. 2 is a schematic diagram showing a cross-sectional laminated structure when a lead is connected to an exposed portion of a current collector in one embodiment of the manufacturing method of the present invention. FIG. 1 is a schematic diagram of a battery according to one embodiment of the present invention.

Fig. 1 is a schematic diagram of a roll body according to one embodiment of the present invention. Fig. 1(a) shows a schematic overall image of a roll body 1 according to one embodiment of the present invention. Fig. 1(b) shows a schematic partial layered structure of the roll body 1.
The roll body 1 of the battery element according to this embodiment is formed by winding a large number of anode sheets 20 each having a cathode current collector layer 22 and an anode active layer 23 formed on a long resin sheet 21, a cathode sheet 30 each having a cathode current collector layer 32 and a cathode active layer 33 formed on a long resin sheet 31, and a separator film 4, with the separator film 4 sandwiched between the anode active layer 23 and the cathode active layer 33.
The negative electrode sheet 20 and the positive electrode sheet 30 are wound with the separator film 4 sandwiched between them, with the negative electrode active layer 23 and the positive electrode active layer 33 facing each other. Therefore, the area sandwiched between the resin sheets of the negative electrode sheet and the positive electrode sheet has a layered structure in which the negative electrode current collector layer 22, the negative electrode active layer 23, the separator film 4, the positive electrode active layer 33, and the positive electrode current collector layer 32 are layered in this order, as shown in FIG. 1( b ). This layered structure is electrically insulated by the resin sheets 21 and 31 and wound in large numbers to form a roll body 1 of a battery element.

As the resin sheet, for example, polyimide, polyester, polypropylene, polyethylene, polyvinylidene chloride, polyethylene terephthalate, polyethylene naphthalate, silicone resin, rubber-based resin, etc. can be used. These resin sheets are preferably insulating and stable against heat, and for example, polyimide can be suitably used. It is preferable to set the thickness of the resin sheet to 50 μm or less, preferably 25 μm or less.

The size and structure of the negative electrode current collector are not particularly limited and can be appropriately selected according to the purpose. The material of the negative electrode current collector can be, for example, die steel, gold, platinum, indium, nickel, copper, stainless steel, etc. The shape of the negative electrode current collector can be, for example, foil, plate, mesh, etc.
The method for forming the negative electrode current collector is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a sputtering method, a vapor deposition method, a CVD method, etc. Alternatively, the negative electrode current collector can be formed by appropriately mixing a metal powder such as copper with a solvent, a resin, etc. to prepare a paste, applying the paste onto a resin sheet, and drying the paste.
The thickness of the negative electrode current collector can be, for example, 5 μm to 500 μm, or preferably 10 μm to 50 μm.

The negative electrode active layer is a semi-solid layer containing a negative electrode active material and an electrolyte. Examples of the negative electrode active material include lithium, lithium alloys, indium, tin, lead, silicon, silicon oxide, and carbon materials, and lithium-containing phosphates, and specific examples include Li3V2(PO4)3, Li3Fe2(PO4)3, and Li4Ti5O12. Only one type of these negative electrode active material particles may be used, or multiple types may be mixed and used.

The electrolyte used in the negative electrode active layer may be, for example, an electrolyte dissolved in an organic solvent, and is not particularly limited, and may be appropriately selected from conventionally known ones according to the purpose. Examples of the organic solvent include esters such as propylene carbonate, ethylene carbonate, and γ-butyrolactone, ethers such as diethyl ether, tetrahydrofuran, substituted tetrahydrofuran, dioxolane, pyran and its derivatives, dimethoxyethane, and diethoxyethane, 3-substituted 2-oxazolidinones such as 3-methyl-2-oxazolidinone, sulfolane, methylsulfolane, acetonitrile, and propionitrile, and only one of these may be used, or a mixture of multiple types may be used. In addition, examples of the electrolyte that can be used include lithium perchlorate, lithium borofluoride, lithium phosphofluoride, lithium aluminate chloride, lithium halide, and lithium trifluoromethanesulfonate.
The thickness of the negative electrode active layer is not particularly limited and can be appropriately selected depending on the purpose, but can be 0.1 μm to 400 μm, preferably 0.5 μm to 200 μm, and more preferably 1 μm to 50 μm.

The shape and material of the positive electrode current collector layer are not particularly limited and can be appropriately selected according to the purpose. For example, die steel, stainless steel, aluminum, aluminum alloy, titanium alloy, copper, nickel, etc. can be used for the positive electrode current collector layer. For example, the shape of the positive electrode current collector layer can be a foil, a plate, a mesh, etc.
The method for forming the positive electrode current collector layer is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a sputtering method, a vapor deposition method, a CVD method, etc. Alternatively, the positive electrode current collector layer can be formed by appropriately mixing a solvent, a resin, etc. with a carbon powder, a metal powder, etc. to prepare a paste, and applying the paste onto a resin sheet and drying it.
The thickness of the positive electrode current collector can be, for example, 5 μm to 500 μm, or preferably 10 μm to 50 μm.

The positive electrode active layer is a semi-solid layer containing a positive electrode active material and an electrolyte. As the positive electrode active material, for example, lithium cobalt oxide, lithium nickel oxide, lithium manganate, a part of these composite oxides substituted with other transition metals, transition metal compounds such as manganese dioxide and vanadium pentoxide, and transition metal chalcogen compounds such as iron sulfide can be used. Specific examples include Li3V2(PO4)3, Li3Fe2(PO4)3, LiMnPO4, LiCoO2, LiNiO2, LiFePO4, LiCoPO4, LiNiPO4, LiCo1/3Ni1/3Mn1/3O2, LiMn2O4, LiNi0.5Mn1.5O4, and Li4Ti5O12. Only one type of these positive electrode active material particles may be used, or a mixture of multiple types may be used.
The electrolyte solution used in the positive electrode active layer may be, for example, an electrolyte dissolved in an organic solvent. There is no particular limitation on the electrolyte solution used in the positive electrode active layer. The electrolyte solution can be the same as that used in the negative electrode active layer, and can be appropriately selected from conventionally known electrolyte solutions according to the purpose.
The thickness of the positive electrode active layer is not particularly limited and can be appropriately selected depending on the purpose, but can be 0.1 μm to 400 μm, preferably 0.5 μm to 200 μm, and more preferably 1 μm to 50 μm.

The positive and negative electrode active layers provided on the long resin sheet contain electrode active material particles and an electrolyte, and can be in a semi-solid state, for example, a particle suspension, colloidal suspension, emulsion, gel, or a mixture of liquid and solid phases, such as a micelle. For this reason, the fluid semi-solid electrode active layer can be applied by supplying it onto the resin sheet from a nozzle or the like. If necessary, the electrode active layer can be fixed on the resin sheet by photopolymerization, plasticization, or gelation. The electrode active layer can be fluidized by high-temperature heating and then fixed at ambient temperature, or it can be fixed by heating to a temperature below the freezing point of the electrolyte.

If liquid leakage or shape maintenance is difficult during the process of forming the electrode active layer on the resin sheet, a gelling agent can be added to the electrode active layer to make it easier to fix the electrode active layer on the resin sheet while maintaining fluidity. The gelling agent can be at least one selected from the group consisting of crosslinkable polymers, polymer gelling agents, low molecular weight gelling agents, and solid fine particles. To prevent a decrease in ionic conductivity due to the addition of a gelling agent, conductive fine particles such as carbon black can be used as the solid fine particles used as the gelling agent.

The separator film used in the present invention is interposed between the positive electrode active layer and the negative electrode active layer, and plays a role in preventing short circuits caused by contact between the active materials of both electrodes and in ensuring electrical conductivity by allowing the electrolyte to penetrate. The separator film may be selected appropriately according to the purpose as long as it is insulating and has sufficient strength even when impregnated with the electrolyte. Specifically, porous films made of polyethylene (PE) or polypropylene (PP) are preferred, and a single layer of each, a two-layer structure of PE/PP, or a three-layer structure of PP/PE/PP can be suitably used.

Next, an example of a method for producing a roll of the battery element of the present invention will be described.
2 is a process flow diagram for explaining one embodiment of the manufacturing method of the present invention. The manufacturing method of this embodiment includes the steps of preparing a wide and long resin sheet 21, preparing a negative electrode roll-shaped raw material in which a large number of negative electrode sheets 20 each having a negative electrode current collector layer 22 and a negative electrode active layer 23 containing at least a negative electrode active material and an electrolyte solution laminated thereon are wound, preparing a positive electrode roll-shaped raw material in which a large number of positive electrode sheets 30 each having a wide and long resin sheet 31, a positive electrode current collector layer 32 and a positive electrode active layer 33 containing at least a positive electrode active material and an electrolyte solution laminated thereon are wound, and preparing a wide and long roll-shaped separator film. a slitting step of overlapping the negative electrode sheet 20 unwound from the negative electrode roll and the positive electrode sheet 30 unwound from the positive electrode roll such that the separator film 4 is sandwiched between the negative electrode active layer 23 and the positive electrode active layer 33, and slitting the overlapped negative electrode sheet 20, separator film 4, and positive electrode sheet 30 into a plurality of narrow-width sheets; and a winding step of winding up each of the plurality of narrow-width sheets into a roll to form a roll of battery element.

3A and 3B are schematic diagrams for explaining a slitting step in one embodiment of the manufacturing method of the present invention, in which (a) is a perspective view and (b) is a side view.
In the slitting process, the negative electrode sheet 20 unwound from the negative electrode roll and the positive electrode sheet 30 unwound from the positive electrode roll are overlapped with the separator film 4 sandwiched therebetween, for example, by nip rolls 5, and cut into a plurality of narrow-width sheets by a slitter head 6. Each narrow-width sheet is then wound into a roll to form a plurality of roll bodies 1.
The slitting process is performed by a slitter. The slitter cuts a wide sheet unwound from a roll into a number of narrow-width sheets using a slitter head, and winds each narrow-width sheet into a roll on a core. For example, as shown in FIG. 3B, when the narrow-width sheet is wound up a predetermined number of times or to a predetermined diameter, the end of the roll is cut by cutter mechanisms 71 and 72, and the roll body 1 wound into a narrow roll is taken out, and the core is rotated by mechanisms 81 and 82 to return the core into the slitter.

FIG. 4 is a schematic diagram showing a laminated structure of a negative electrode sheet 20, a separator film 4, and a positive electrode sheet 30 in one embodiment of the manufacturing method of the present invention.
An example of the manufacturing method of the present invention will be described with reference to FIG. 4. A wide and long resin sheet is prepared, and a negative electrode current collector layer and a negative electrode active layer are sequentially laminated to form a negative electrode sheet 20.
The method of forming the laminated layers includes, for example, preparing a paste by appropriately mixing the base material of each layer with a solvent, resin, etc. as necessary, and applying the paste of each layer sequentially onto a resin sheet using, for example, a nozzle method, a gravure method, a screen method, or other application method, and drying to form the negative electrode sheet 20.
The negative electrode current collector can be formed, for example, by mixing a metal powder such as copper with a solvent, a resin, etc., to prepare a paste, applying the paste onto a resin sheet, and drying the paste. After application, the negative electrode current collector may be hot-pressed with a roll press or the like, if necessary.
The negative electrode active layer can be formed by a coating method in which a semi-solid paste containing electrode active material particles and an electrolyte is supplied onto a resin sheet from a nozzle or the like.
In a similar manner, a positive electrode sheet 30 for forming a positive electrode is formed.
The separator film 4 can be appropriately selected from conventionally known materials such as polyethylene (PE) and polypropylene (PP) depending on the purpose.
This results in the preparation of a negative electrode roll-shaped raw material having a multiplicity of negative electrode sheets 20 wound around it, a positive electrode roll-shaped raw material having a multiplicity of positive electrode sheets 30 wound around it, and a roll-shaped separator film, all of which have a layered configuration as shown in FIG. 4( a).

Next, the negative electrode roll, the positive electrode roll, and the roll of separator film are set in the unwinding mechanism of the slitting device, and the negative electrode sheet 20 is unwound from the negative electrode roll, the positive electrode sheet 30 is unwound from the positive electrode roll, and the separator film 4 is unwound from the roll of separator film. The negative electrode sheet 20 unwound from the negative electrode roll, the positive electrode sheet 30 unwound from the positive electrode roll, and the separator film 4 unwound from the roll of separator film are stacked with the separator film 4 sandwiched between nip rolls with the active layers of each electrode facing each other, resulting in a laminated structure as shown in FIG. 4(b).

The negative electrode sheet 20, the positive electrode sheet 30, and the separator film 4 are cut into multiple narrow sheets by a slitter head and wound into a roll, resulting in multiple stacks of the negative electrode sheet 20, the separator film 4, and the positive electrode sheet 30, as shown in FIG. 4(c). This stacked state results in a roll body in which the negative electrode collector layer and the positive electrode collector layer are insulated by a resin sheet.

The manufacturing method of the present invention has been described above, but the present invention can add necessary steps depending on the battery shape and application.

Alternatively, at least a portion of the rolled-up roll body 1, typically the outermost and innermost surfaces, may be provided with a collector exposed portion where the negative and positive collector layers are exposed (FIG. 5). By connecting a negative lead to the collector exposed portion of the negative collector layer and a positive lead to the collector exposed portion of the positive collector layer, electrical connection with other electrical components can be achieved (FIG. 6). The exposed portions can be formed by, for example, shot blasting, sand blasting, polishing, elution, cutting, and other methods.

The roll body 1 produced as described above is housed in a battery case, for example as shown in FIG. 7. There are no particular limitations on the battery case and it can be appropriately selected depending on the purpose, and examples of the battery case include known laminate films and housings that can be used in conventional batteries. There are no particular limitations on the shape of the battery and it can be appropriately selected depending on the purpose, and examples of the battery case include cylindrical, square, button, coin, and flat types.

Reference Signs List 1 Roll body 20 Negative electrode sheet 21, 31 Resin sheet 22 Negative electrode current collector layer 23 Negative electrode active layer 4 Separator film 32 Positive electrode current collector layer 33 Positive electrode active layer 5 Nip roll 6 Slitter heads 71, 72 Cutter mechanism 81, 82 Roll core rotation mechanism

Claims (12)

A roll of battery elements, in which a negative electrode sheet is formed on a first long resin sheet, in which a negative electrode current collector layer and a negative electrode active layer containing at least a negative electrode active material and an electrolyte are provided in this order, and a positive electrode sheet is formed on a second long resin sheet, in which a positive electrode current collector layer and a positive electrode active layer containing at least a positive electrode active material and an electrolyte are provided in this order, are wound up facing each other with a separator film sandwiched between the negative electrode active layer and the positive electrode active layer. The roll body according to claim 1, wherein at least one of the negative electrode active layer and the positive electrode active layer contains a gelling agent. The roll body according to claim 2, wherein the gelling agent is at least one selected from the group consisting of crosslinkable polymers, polymeric gelling agents, low molecular weight gelling agents, and solid particles. The roll body according to claim 3, wherein the gelling agent is a solid fine particle, and the solid fine particle is a conductive fine particle. The roll body according to claims 1 to 4, comprising a negative electrode collector exposed portion where the negative electrode collector layer is exposed, and a positive electrode collector exposed portion where the positive electrode collector layer is exposed. The roll body according to claim 5, wherein a negative electrode lead is connected to the negative electrode collector exposed portion, and a positive electrode lead is connected to the positive electrode collector exposed portion. A battery in which the roll body according to any one of claims 1 to 6 is housed in a battery case. a step of preparing a rolled negative electrode raw material by winding a negative electrode sheet having a negative electrode current collector layer and a negative electrode active layer containing at least a negative electrode active material and an electrolyte solution provided in this order on a first surface of a wide and long first resin sheet;
a step of preparing a positive electrode roll-shaped raw material by winding a positive electrode sheet having a positive electrode current collector layer and a positive electrode active layer containing at least a positive electrode active material and an electrolyte solution provided in this order on a first surface of a wide and long second resin sheet; a step of preparing a wide and long roll-shaped separator film;
a slitting step of overlapping the negative electrode sheet unwound from the negative electrode roll and the positive electrode sheet unwound from the positive electrode roll so as to face each other with a separator film sandwiched between the negative electrode active layer and the positive electrode active layer, and slitting the overlapped negative electrode sheet, separator film, and positive electrode sheet into a plurality of narrow-width sheets;
and a winding step of winding each of the narrow sheets into a roll to form a roll of battery elements. the slitting step includes a step of cutting the negative electrode sheet unwound from the negative electrode roll and the positive electrode sheet unwound from the positive electrode roll into the plurality of narrow-width sheets by a slitter head in a state in which the negative electrode sheet and the positive electrode sheet are overlapped with each other so as to face each other with a separator film sandwiched between the negative electrode active layer and the positive electrode active layer,
The method according to claim 8 , wherein the winding step includes a step of cutting off an end of the narrow sheet when the narrow sheet has been wound up a predetermined number of times or to a predetermined diameter. the step of preparing a negative electrode roll includes a step of coating the negative electrode current collector layer and the negative electrode active layer in this order on the wide and long first resin sheet,
10. The manufacturing method according to claim 8 or 9, wherein the step of preparing the positive electrode rolled raw material includes a step of coating the positive electrode current collector layer and the positive electrode active layer in this order on the wide and long second resin sheet. The manufacturing method according to any one of claims 8 to 10, further comprising a step of forming, on the roll body, a negative electrode current collector exposed portion where the negative electrode current collector layer is exposed, and a positive electrode current collector exposed portion where the positive electrode current collector layer is exposed. The method of claim 11 further comprises the step of connecting a negative electrode lead to the exposed portion of the negative electrode current collector and connecting a positive electrode lead to the exposed portion of the positive electrode current collector.

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