JP2011216207A - Manufacturing method of laminated battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a laminated battery enabling reduction of resin reservoir.SOLUTION: The manufacturing method of the laminated battery includes: a first process in which resin is coated on one main face of a first laminate film to be arranged on one side of a laminate formed by laminating a sheet-shaped positive electrode and a sheet-shaped negative electrode via a separator, and on one main face of a second laminate film to be arranged on the other side of the laminate; a second process in which recessed parts are formed in the resin coated in a region out of at least one of first and second laminate films which becomes a seal part; a third process in which the first and second laminate films are arranged on both sides of the laminate so that the laminate is sandwiched by one main face of the first laminate film and one main face of the second laminate film; and a fourth process in which the region to become the seal part of the first laminate film and the region to become the seal part of the second laminate film are welded to each other.

Description

  The present invention relates to a method for manufacturing a laminated battery.

  Conventionally, a laminated battery in which a pair of internal electrodes formed by laminating a positive electrode and a negative electrode via a separator is laminated with an exterior material is known (Patent Document 1).

  In this laminated battery, the exterior material has a thermoplastic resin excellent in electrolytic solution resistance and heat sealability such as polyethylene, polypropylene, and polyamide on the inner surface. Then, by thermally welding this thermoplastic resin, the edge of the exterior material is welded, and the internal electrode pair is laminated by the exterior material.

JP 2006-40747 A

  However, the conventional laminated battery has a problem that a resin pool is generated in the thermoplastic resin when the thermoplastic resin is thermally welded.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a method for manufacturing a laminated battery capable of reducing a resin reservoir.

  According to the embodiment of the present invention, a method for manufacturing a laminate-type battery includes a main component of a first laminate film to be disposed on one side of a laminate in which a sheet-like positive electrode and a sheet-like negative electrode are laminated via a separator. A first step of applying resin to the surface and one main surface of the second laminate film to be disposed on the other side of the laminate, and a seal among at least one of the first and second laminate films The first step so as to sandwich the laminate between the second step of forming a recess in the resin applied to the region to be a part, and one main surface of the first laminate film and one main surface of the second laminate film A third step of disposing a second laminate film on both sides of the laminate, and a fourth step of welding a resin applied to a region to be a seal portion of the first and second laminate films Provided with a door.

  According to the embodiment of the present invention, since at least one of the first and second laminate films includes the resin in which the concave portion is formed in the region to be the seal portion, the first and second laminates are provided. In the welding of the film, the resin of the first laminate film is welded to the resin of the second laminate film while the melted resin is accommodated in the recess.

  Therefore, the resin pool can be reduced in the seal portion.

It is a top view of the laminate type battery in embodiment of this invention. FIG. 2 is a cross-sectional view of a laminated battery between line II and II shown in FIG. 1. FIG. 3 is an enlarged cross-sectional view of a part of the laminate film shown in FIG. 2. It is an enlarged view before welding of the seal part shown in FIG. It is a conceptual diagram when welding a laminate film. It is a conceptual diagram after welding of two laminate films. It is a top view of a laminate film. It is sectional drawing of another recessed part. It is process drawing which shows the manufacturing method of the laminated battery by embodiment of this invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a plan view of a laminated battery according to an embodiment of the present invention. 2 is a cross-sectional view of the laminated battery taken along line II-II shown in FIG.

  Referring to FIGS. 1 and 2, a laminated battery 10 includes a sheet-like positive electrode 1, a sheet-like negative electrode 2, a separator 3, a laminate film 4, a positive electrode external terminal 5, and a negative electrode external terminal 6. .

  The sheet-like positive electrode 1, the sheet-like negative electrode 2, and the separator 3 are laminated to constitute a laminate 20. The sheet-like positive electrode 1 has a size smaller than that of the sheet-like negative electrode 2 in the in-plane direction DR1 of the laminated battery 10. The sheet-like negative electrode 2 has a size smaller than that of the separator 3 in the in-plane direction DR1.

  The sheet-like positive electrode 1, the sheet-like negative electrode 2, and the separator 3 are arranged such that both ends of the separator 3 are located outside the both ends of the sheet-like negative electrode 2 in the in-plane direction DR 1. It arrange | positions so that it may be located outside the both ends of 1.

  The laminate film 4 has a substantially rectangular planar shape and accommodates the laminate 20. And the edge part of the laminate film 4 is sealed. The positive electrode external terminal 5 has a planar shape, and one end thereof is connected to the sheet-like positive electrode 1 directly or via a lead body 7. The other end of the positive electrode external terminal 5 is drawn outside through the laminate film 4.

  The negative external terminal 6 has a planar shape, and one end thereof is connected to the sheet-like negative electrode 2 directly or via a lead body. The other end of the negative electrode external terminal 6 is pulled out via the laminate film 4.

  In FIG. 1, the positive external terminal 1 and the negative external terminal 2 are drawn from the same side of the laminate film 4. However, in the embodiment of the present invention, the positive external terminal 5 and the positive external terminal 5 are not limited thereto. The negative external terminal 6 may be drawn out from different sides of the laminate film 4.

  The sheet-like positive electrode 1 has, for example, a structure in which a layer (positive electrode mixture layer) made of a positive electrode mixture containing a positive electrode active material, a conductive additive, a binder, and the like is formed on one side or both sides of a current collector.

For example, when the laminated battery 10 is a lithium ion secondary battery, the positive electrode active material is made of an active material that can occlude and release lithium ions. Such a positive electrode active material is, for example, a lithium-containing transition metal having a layered structure represented by Li _{1 + x} MO ₂ (−0.1 <x <0.1, M: Co, Ni, Mn, Al, Mg, etc.) Oxides, LiMn ₂ O ₄ , lithium manganese oxide having a spinel structure in which some of the elements are replaced with other elements, and olivine type compounds represented by LiMPO ₄ (M: Co, Ni, Mn, Fe, etc.) Consisting of either.

The lithium-containing transition metal oxide having a layered structure is, for example, LiCoO ₂ , LiNi _1-x Co _xy Al _y O ₂ (0.1 ≦ x ≦ 0.3, 0.01 ≦ y ≦ 0.2). And an oxide containing at least Co, Ni and Mn (LiMn _1/3 Ni _1/3 Co _1/3 O ₂ , LiMn _5/12 Ni _5/12 Co _1/6 O ₂ , LiNi _3/5 Mn _{1 / 5} Co _1/5 O ₂ ).

  The current collector of the positive electrode is made of, for example, an aluminum foil or an aluminum alloy foil. The thickness of the current collector varies depending on the size and capacity of the battery, but is, for example, 0.01 to 0.02 mm.

  The sheet-like positive electrode 1 is produced by the following method. A positive electrode mixture containing a positive electrode active material, a conductive additive such as graphite, acetylene black, carbon black, and fibrous carbon, and a binder such as polyvinylidene fluoride (PVDF) is mixed with N-methyl-2-pyrrolidone (NMP). ) Or the like to prepare a paste-like or slurry-like composition uniformly dispersed (the binder may be dissolved in the solvent). And this composition is apply | coated on a positive electrode electrical power collector, it dries, and the thickness of a positive mix layer is adjusted by press processing as needed. Thereby, the sheet-like positive electrode 1 is produced.

  In the embodiment of the present invention, the sheet-like positive electrode 1 may be produced using a method other than the method described above.

  The thickness of the positive electrode mixture layer in the sheet-like positive electrode 1 is preferably 30 to 100 μm per one side. Moreover, it is preferable that content of each structural component in a positive mix layer shall be positive electrode active material: 90-98 mass%, conductive support agent: 1-5 mass%, and binder: 1-5 mass%.

  The positive electrode external terminal 5 is preferably made of aluminum or an aluminum alloy from the viewpoint of easy connection with the equipment used.

  The thickness of the positive external terminal 5 is preferably 50 to 300 μm. That is, by setting the thickness of the positive external terminal 5 to 50 μm or more, the positive external terminal 5 can be prevented from being cut during welding of the positive external terminal 5, and the positive external terminal 5 is torn by pulling and bending. Can be prevented. Further, by setting the thickness of the positive electrode external terminal 5 to 300 μm or less, it is possible to prevent a gap in the thickness direction from being generated in the heat seal portion of the laminate film 4.

  In addition, in order to increase the adhesive strength between the laminate film 4 and the positive electrode external terminal 5, a resin adhesive layer (for example, a laminate film) is provided in advance at a location where the positive electrode external terminal 5 is expected to be located in the heat seal portion. 4 may be provided with an adhesive layer made of the same kind of resin as the resin constituting the heat-sealing resin layer of the metal laminate film constituting 4.

  Examples of the method of connecting the current collector in the sheet-like positive electrode 1 or the aluminum lead body 7 connected to the current collector and the positive external terminal 5 include resistance welding, ultrasonic welding, laser welding, caulking, and Various methods such as a method using a conductive adhesive can be employed. Of these, ultrasonic welding is particularly suitable.

  For example, when the laminated battery 10 is a lithium ion secondary battery, the sheet-like negative electrode 2 includes an active material that can occlude and release lithium ions. Such negative electrode active materials occlude and release lithium ions such as graphite, pyrolytic carbons, cokes, glassy carbons, fired organic polymer compounds, mesocarbon microbeads (MCMB), and carbon fibers. It consists of one or a mixture of two or more possible carbon-based materials.

Other negative electrode active materials include, for example, elements such as Si, Sn, Ge, Bi, Sb, and In, alloys of Si, Sn, Ge, Bi, Sb, and In, lithium-containing nitrides, and lithium oxides. It consists of a compound (LiTi ₃ O ₁₂ or the like) that can be charged and discharged at a low voltage close to lithium metal, lithium metal, and a lithium / aluminum alloy.

  These negative electrode active materials include a conductive additive (made of the same material as the positive electrode conductive additive), a binder (a binder of PVDF, rubber binder such as styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC), etc. ) Is added as appropriate to the negative electrode mixture, and the current collector is a finished product (negative electrode mixture layer) using the current collector as a core material, or the above-described various alloys or lithium metal foils. Those laminated on the surface are used as the sheet-like negative electrode 2.

  And the sheet-like negative electrode 2 is produced by the following method. A paste in which a negative electrode mixture containing the above-described negative electrode active material, a binder, and, if necessary, a conductive additive such as graphite, acetylene black, and carbon black is uniformly dispersed using a solvent such as NMP. Alternatively, a slurry-like composition is prepared (the binder may be dissolved in a solvent). And this composition is apply | coated on a negative electrode electrical power collector, it dries, and the thickness or density of a negative mix layer is adjusted by press processing as needed. Thereby, the sheet-like negative electrode 2 is produced.

  In the embodiment of the present invention, the sheet-like negative electrode 2 may be produced using a method other than the method described above.

  As the current collector for the negative electrode, a copper foil is suitable. And although the thickness of an electrical power collector is based on the magnitude | size or capacity | capacitance of a battery, it is preferable that it is 0.05-0.02 mm, for example.

  The thickness of the negative electrode mixture layer in the sheet-like negative electrode 2 is preferably 30 to 100 μm per side. Moreover, it is preferable that content of each structural component in a negative mix layer is 90-98 mass% of negative electrode active materials, and 1-5 mass% of binders. Moreover, when using a conductive support agent for a negative electrode, it is preferable that content of the conductive support agent in a negative mix layer is 1-5 mass%.

  The negative external terminal 6 is made of a metal foil or ribbon such as nickel, nickel-plated copper, and nickel-copper clad. Further, the thickness of the negative electrode external terminal 6 is preferably 50 to 300 μm like the positive electrode external terminal 5.

  That is, by setting the thickness of the negative electrode external terminal 6 to 50 μm or more, the negative electrode external terminal 6 can be prevented from being cut during welding of the negative electrode external terminal 6, and the negative electrode external terminal 6 is broken by pulling and bending. Can be prevented. Moreover, by setting the thickness of the negative electrode external terminal 6 to 300 μm or less, it is possible to prevent a gap in the thickness direction from being generated in the heat seal portion of the laminate film 4.

  In addition, in order to increase the adhesive strength between the laminate film 4 and the negative electrode external terminal 6, a resin adhesive layer (for example, a laminate film) is preliminarily provided at a position where the negative electrode external terminal 6 is supposed to be located in the heat seal portion. 4 may be provided with an adhesive layer made of the same kind of resin as the resin constituting the heat-sealing resin layer of the metal laminate film constituting 4.

  The connection between the sheet-like negative electrode 2 and the negative electrode external terminal 6 may be performed by directly connecting the current collector of the sheet-like negative electrode 2 and the negative electrode external terminal 6, for example, via a copper lead body It may be done. The thickness of the copper lead body is preferably 50 to 300 μm, similarly to the negative electrode external terminal 6. Such a lead body is particularly preferably used when the copper foil as the negative electrode current collector is thin and the strength is insufficient for direct connection to the negative electrode external terminal 6.

  The connection between the current collector in the sheet-like negative electrode 2 or the copper lead body connected to the current collector and the negative electrode external terminal 6 is, for example, by resistance welding, ultrasonic welding, laser welding, caulking, and conductive adhesive. It is performed by various methods such as a method. Among these methods, ultrasonic welding is particularly suitable.

  The separator 3 is made of, for example, a porous film or a nonwoven fabric made of polyethylene, polypropylene, a fusion of polyethylene and polypropylene, polyethylene terephthalate, polybutylene terephthalate, or the like.

  The thickness of the separator 3 is preferably 10 to 50 μm, and the porosity is preferably 30 to 70%.

  Moreover, the effect which prevents a short circuit can be improved and the reliability of a battery can be improved more by using several separators, such as overlapping a porous film and a nonwoven fabric.

When the laminate battery 10 is a lithium ion secondary battery, the electrolyte used for the laminate battery 10 is, for example, a solution (non-aqueous solution) in which a solute such as LiPF ₆ or LiBF ₄ is dissolved in a high dielectric constant solvent or an organic solvent. Electrolyte). As the high dielectric constant solvent, ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (BL), or the like can be used. The organic solvent is composed of a low-viscosity solvent such as linear dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC).

  In addition, it is preferable to use the mixed solvent of the high dielectric constant solvent mentioned above and a low-viscosity solvent as electrolyte solution solvent. Alternatively, PVDF, a rubber-based material, an alicyclic epoxy, a material having an oxetane-based three-dimensional crosslinked structure, and the like may be mixed and solidified into the above-described solution to form a polymer electrolyte.

  FIG. 3 is an enlarged cross-sectional view of a part of the laminate film 4 shown in FIG. With reference to FIG. 3, the laminate film 4 includes a laminate film 4a disposed on the upper side and a laminate film 4b disposed on the lower side. Each of the laminate films 4 a and 4 b includes a metal layer 41 and resins 42 and 43.

  The metal layer 41 is made of, for example, an aluminum film or a stainless steel film. And the thickness of the metal layer 41 is 10-150 micrometers, for example.

  The resin 42 is formed on the outer surface of the metal layer 41. The resin 42 is a resin for an electrolytic solution. And the resin 42 consists of either a nylon film, (nylon 66 film etc.), and a polyester film (PET film etc.), for example. The thickness of the resin 42 is 20 to 100 μm.

  The resin 43 is formed on the inner surface of the metal layer 41 of the laminate film 4a or the laminate film 4b, and has a thickness of 40 to 80 μm, for example. The resin 43 is made of, for example, a modified polyolefin film (modified polyolefin ionomer film). The resin 43 functions as a heat welding resin.

  Each of the laminate films 4 a and 4 b has a seal portion 40. The seal portion 40 has a width W in the in-plane direction DR1. The width W is 10 mm, for example.

  FIG. 4 is an enlarged view of the seal portion 40 shown in FIG. 3 before welding. Referring to FIG. 4, laminate film 4 a has a region 400 that becomes seal portion 40 before welding. The region 400 has a width W in the in-plane direction DR1. Further, the region 400 has a recess 8 a formed on one main surface 43 </ b> A of the resin 43.

  The recess 8a has a width w and a depth d in the in-plane direction DR1. The width w is, for example, 0.01 to 5 mm. The depth d is set to about 1/2 to 1/10 of the thickness of the resin 43, for example. Specifically, the thickness is preferably about 4 to 20 μm.

  When the distance from one end 400A of the region 400 to be the seal portion 40 of the laminate film 4a to the center of the recess 8a is x, the distance x is set in a range of 1.01 to 3.5 mm ≦ x ≦ W / 2 mm. The

  The laminate film 4b has a recess (not shown) having the same size and arrangement position as the recess 8a.

  FIG. 5 is a conceptual diagram when a laminate film is welded. With reference to FIG. 5, the resin 43 of the laminate film 4b has a recess 8b. The recess 8b has the same size as the recess 8a, and is formed in the resin 43 of the laminate film 4b at a position facing the recess 8a formed in the resin 43 of the laminate film 4a.

  Then, the laminate films 4a and 4b are overlapped so that the resin 43 of the laminate film 4a is in contact with the resin 43 of the laminate film 4b. As a result, the recess 8a faces the recess 8b.

  After that, the resin 43 of the laminate film 4a is welded to the resin 43 of the laminate film 4b by sandwiching the outer periphery of the two laminated films 4a and 4b with the two seal bars (heaters) 50 and 60. In this case, the heating temperature is, for example, 180 to 220 ° C., the pressing pressure at the time of heat sealing is, for example, 0.1 MPa to 0.5 MPa, and the pressing time is 3 to 20 seconds.

  When the resin 43 of the laminate film 4a is welded to the resin 43 of the laminate film 4b, the resin 43 of the laminate films 4a and 4b melts and moves in the in-plane direction DR1, but since the recesses 8a and 8b exist, the in-plane The resin 43 moved in the direction DR1 is accommodated in the recesses 8a and 8b.

  Therefore, the resin pool can be reduced.

  FIG. 6 is a conceptual diagram after welding of two laminated films. Referring to FIG. 6, when laminate films 4a and 4b have recesses 8a and 8b, respectively, in regions 400 that become seal portions 40, resin 43 of laminate films 4a and 4b maintains flatness after welding. Yes. The resin 43 of the laminate film 4a is in close contact with the resin 43 of the laminate film 4b (see FIG. 6A). This is because the melted resin 43 of the laminate films 4a and 4b is accommodated in the recesses 8a and 8b at the time of welding.

  On the other hand, each of the conventional laminate films 140a and 140b includes a metal layer 141 and resins 142 and 143. The metal layer 141 and the resin 142 are the same as the metal layer 41 and the resin 42, respectively. The resin 143 is made of the same material as the resin 43 and is applied to the entire inner surface of the metal layer 141.

  When the resin 143 of the laminate film 140a is welded to the resin 143 of the laminate film 140b, a resin pool 144 is generated, and a portion 145 where the resin 143 of the laminate film 140a is not bonded to the resin 143 of the laminate film 140b is generated (FIG. 6). (See (b)).

  Thus, by forming the recesses 8a and 8b in the resin 43 applied to the region 400 to be the seal portion 40 of the laminate films 4a and 4b, the occurrence of the resin pool 144 can be reduced. As a result, the resin 43 of the laminate film 4a can be adhered to the resin 43 of the laminate film 4b.

There are the following three methods for accommodating the laminate 20 in the laminate film 4.
(1) A method in which the laminate 20 is sandwiched between two laminate films, and then the outer periphery of these two laminate films is heat-sealed leaving one side for injecting an electrolyte solution (2) Laminate films A method of inserting the laminate 20 from one side for injecting the electrolyte solution into a laminate film previously formed into a bag shape, leaving one side for injecting the electrolyte solution in the outer periphery of the laminate (3) Lamination on the laminate film The body 20 is placed, the laminate film is folded in half so as to wrap the laminate 20, and the remaining outer periphery is heat-sealed leaving one side for injecting the electrolyte solution. (The folded part that is folded may be heat-sealed or not heat-sealed)
FIG. 7 is a plan view of a laminate film. With reference to FIG. 7, when the laminated body 20 is accommodated in the laminate film 4 using the methods (1) and (2) described above, two laminate films 4a and 4b are prepared. And the recessed part 8a is formed in the resin 43 apply | coated to the area | region 400 used as the seal part 40 of the laminate film 4a, and the recessed part 8b is formed in the resin 43 apply | coated to the area | region 400 used as the seal part 40 of the laminate film 4b ( (See (a) of FIG. 7). In this case, the recesses 8a and 8b are formed, for example, by pressing the resin 43 applied to the regions 400 of the laminate films 4a and 4b with a mold.

  Thereafter, two laminate films 4a and 4b are arranged on both sides of the laminate 20 so that the recess 8a and the recess 8b face each other, and one side for injecting the electrolyte around the outer periphery of the two laminate films 4a and 4b. Leave a heat seal. In this case, one of the laminate films 4 a and 4 b is a laminate film disposed on one side of the laminate 20, and the other of the laminate films 4 a and 4 b is disposed on the other side of the laminate 20. Laminated film.

  Moreover, when accommodating the laminated body 20 in the laminate film 4 using the method (3) mentioned above, the one laminate film 4 is prepared. And the recessed part 8 is formed in the resin 43 apply | coated to the area | region 400 used as the seal part 40 of the laminate film 4 (refer FIG.7 (b)).

  The concave portion 8 has the same size as the concave portions 8 a and 8 b described above, and is formed at a substantially central portion of the region 400 in the in-plane direction of the laminate film 4. Also in this case, the recesses 8 are formed, for example, by pressing the resin 43 applied to the region 400 of the laminate film 4 with a mold.

  Thereafter, the laminate 20 is disposed on one of the two regions 401 and 402 of the laminate film 4, and the other of the two regions 401 and 402 of the laminate film 4 is bounded so as to wrap the laminate 20. Return at 44. Then, the remaining outer periphery is heat-sealed, leaving one side for injecting the electrolyte. In this case, in the laminate film 4, the laminate film composed of the region 401 is a laminate film disposed on one side of the laminate 20, and the laminate film composed of the region 402 is disposed on the other side of the laminate 20. Laminated film.

  In the above description, the recesses 8a, 8b or the recesses 8 are the region 400 that becomes the seal portion 40 of the laminate film disposed on one side of the laminate 20, and the laminate film disposed on the other side of the laminate 20. In the embodiment of the present invention, the concave portion formed in the region 400 to be the seal portion 40 is not limited to this, but the recessed portion formed in the region 400 to be the seal portion 40 has been described. It may be formed on only one of the two laminated films disposed on both sides of the film.

  In this case, when the laminated body 20 is accommodated in the laminate film 4 using the methods (1) and (2) described above, the recess 8a (or the recess 8b) is formed only in one of the laminate films 4a and 4b. When the laminate 20 is accommodated in the laminate film 4 using the method (3) described above, the recess 8 is formed only in one of the regions 401 and 402 of the laminate film 4.

  FIG. 8 is a cross-sectional view of another recess. With reference to FIG. 8, the recessed part 80 may be formed in resin 43 of the laminate films 4, 4a, and 4b. The concave portion 80 has a cross-sectional shape in which a taper is formed so as to become deeper from both ends toward the central portion, and has a width w in the in-plane direction DR1. And the depth in the center part of the recessed part 80 is set to the depth d mentioned above. Further, the distance from the one end 400A of the region 400 to the central portion of the recess 80 is set to the distance x described above (see FIG. 8A).

  In addition, a recess 81 may be formed in the resin 43 of the laminate films 4, 4a, 4b. The recess 81 has a cross-sectional shape that is tapered so as to become deeper from one end toward the other end, and has a width w in the in-plane direction DR1. And the depth in the other end of the recessed part 81 is set to the depth d mentioned above. Further, the distance from the one end 400A of the region 400 to the central portion of the recess 81 is set to the above-described distance x (see FIG. 8B).

  The recess 81 has a cross-sectional shape in which a taper is formed so as to gradually become deeper from the left side to the right side on the paper surface of FIG. 8, but the embodiment of the present invention is not limited to this, The concave portion 81 may have a cross-sectional shape in which a taper is formed so as to gradually become deeper from the right side to the left side on the paper surface of FIG.

  Further, the recess formed in the resin 43 of the laminate films 4, 4 a, 4 b is not limited to the cross-sectional shape described above, but a cross-sectional shape that can accommodate the resin 43 melted when the laminate films 4, 4 a, 4 b are welded. Any cross-sectional shape may be used.

  FIG. 9 is a process diagram showing a method for manufacturing a laminated battery according to an embodiment of the present invention. Referring to FIG. 9, when production of laminated battery 10 is started, one main surface of first laminated film (= for example, laminated film 4 a) to be disposed on one side of laminated body 20 and laminated body 20. The resin 43 is applied to one main surface of the second laminate film (= for example, the laminate film 4b) to be disposed on the other side (step S1).

  And the recessed part (= at least 1 recessed part of recessed part 4a, 4b) is formed in resin 43 apply | coated to the area | region 400 used as the seal | sticker part 40 among at least one laminated film of a 1st and 2nd laminated film ( Step S2).

  Thereafter, the first and second laminate films are arranged on both sides of the laminate so that the laminate 20 is sandwiched between the one principal surface of the first laminate film and the one principal surface of the second laminate film (step S3). .

  If it does so, the laminated body 20 will be accommodated in the laminate film 4 using the method in any one of the method (1)-(3) mentioned above, and sides other than the one side which inject | pours electrolyte solution will be heat-sealed (step S4).

  And electrolyte solution is inject | poured (step S5), and the one side which inject | poured electrolyte solution is heat-sealed while evacuating the inside of the laminate film 4 from one side inject | poured electrolyte solution (step S6).

  Thereby, the laminated battery 10 is completed.

  In addition, when a recessed part is formed in both the 1st and 2nd laminated films, the recessed part becomes the area | region 400 used as the sealing part 40 of a 1st laminated film, and the sealing part 40 of a 1st laminated film in step S2. And the region 400 to be formed.

  As described above, according to the embodiment of the present invention, the laminate films 4a and 4b include the resin 43 in which the recesses 8a and 8b are formed in the region 400 to be the seal portion 40. In the welding of 4a and 4b, the resin 43 of the laminate film 4a is welded to the resin 43 of the laminate film 4b while the melted resin 43 is accommodated in the recesses 8a and 8b.

  Therefore, the resin pool can be reduced in the seal portion 40. As a result, the adhesion of the resin can be improved.

  In the above description, the laminated battery 10 has been described as including the laminated electrode body in which the sheet-like positive electrode 1 and the sheet-like negative electrode 2 are laminated via the separator 3, but in the embodiment of the present invention, However, the laminated battery may include a wound electrode body in which the sheet-like positive electrode 1 and the sheet-like negative electrode 2 that are overlapped via the separator 3 are wound in a spiral shape. In addition, when a wound electrode body is used, you may shape | mold so that a cross section may become flat shape as needed.

  In the above description, the laminate films 4, 4 a, 4 b have been described as having a square planar shape. However, in the embodiment of the present invention, the present invention is not limited to this, and the laminate films 4, 4 a, 4 b are triangular. , Pentagonal, hexagonal, heptagonal, octagonal and other various planar shapes.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a method for manufacturing a laminated battery.

  DESCRIPTION OF SYMBOLS 1 Sheet-like positive electrode, 2 Sheet-like negative electrode, 3 Separator, 4, 4a, 4b, 140a, 140b Laminating film, 5 Positive external terminal, 6 Negative external terminal, 7 Lead body, 8, 8a, 8b Recessed part, 10 Laminated battery , 20 laminate, 40 seal part, 41, 141 metal layer, 42, 43, 142, 143 resin, 50, 60 seal bar, 400 region.

Claims (3)

One main surface of a first laminate film to be arranged on one side of a laminate in which a sheet-like positive electrode and a sheet-like negative electrode are laminated via a separator, and a second laminate film to be arranged on the other side of the laminate A first step of applying a resin to one main surface;
A second step of forming a recess in a resin applied to a region to be a seal portion of at least one of the first and second laminate films;
The third and second laminate films are arranged on both sides of the laminate so that the laminate is sandwiched between one principal surface of the first laminate film and one principal surface of the second laminate film. And the process of
And a fourth step of welding a resin applied to a region to be the seal portion of the first and second laminate films.   In the second step, the concave portion includes a resin applied to a region to be the seal portion of the first laminate film and a resin applied to a region to be the seal portion of the second laminate film. The manufacturing method of the laminated battery of Claim 1 formed in both.   The said recessed part is formed in the approximate center part of resin apply | coated to the area | region used as the said seal part in the surface direction of the said 1st and 2nd laminate film in a said 2nd process. Item 3. A method for producing a laminated battery according to Item 2.

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