JP2011175847A - Outer package for electrochemical device, and electrochemical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer package for an electrochemical device, capable of reducing a dead space, and having a sealing structure superior in pressure resistance. <P>SOLUTION: The outer package for the electrochemical device for housing a power-generating element of the electrochemical device inside is provided with a sealing part structured of a first laminate film 51 and a second laminate film 52 opposed to each other with edges of the first and the second laminate films 51, 52 adhered to each other. At least part of the sealing part turns to be an outer-face sealing part 5 with an edge of the second laminate film 52 bent and adhered so as to be overlapped with an edge of a face at an outside of the outer package of the first laminate film 51. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exterior body for an electrochemical device and an electrochemical device.

  As electrochemical devices such as batteries and electric double layer capacitors, those using an aluminum laminate outer package have been put into practical use. The aluminum laminate outer package is advantageous in that it is lightweight and has a high degree of freedom in shape.

  The structure of the conventional laminate exterior body has a structure in which a laminate film is sealed by a hot press or the like at an adhesive margin portion provided around the power generation element accommodating portion (see, for example, Patent Documents 1 to 4). In these structures of the laminate outer package, a dead space corresponding to the paste margin is generated, and thus it is proposed to save space by folding the paste margin portion (seal part) of the laminate package (for example, Patent Document 5). To 9).

JP 2000-77043 A JP 2000-133216 A JP 2000-149993 A JP 2000-285904 A Japanese Patent Laid-Open No. 2000-200585 JP 2000-251855 A JP 2000-268807 A JP 2001-325925 A Japanese Patent Application Laid-Open No. 2001-325943

  However, even in the structure of the laminate outer package described in Patent Documents 5 to 9, the folded paste margin portion becomes a dead space, so there is room for further reduction of the dead space. Moreover, in the structure of the laminated exterior body described in the said patent documents 1-9, when the internal pressure inside an exterior body rises, there exists a problem that a paste margin part is gradually expanded and peeling will arise easily.

  The present invention has been made in view of the above-described problems of the prior art, can reduce dead space, and has an outer sealing body having an excellent pressure resistance, and an electrochemical device using the same. The purpose is to provide.

  In order to achieve the above object, the present invention is an exterior body for accommodating a power generation element of an electrochemical device, and is constituted by a first laminate film and a second laminate film facing each other, and It has a seal part formed by bonding edges of the first and second laminate films, and at least a part of the seal part has an edge of the second laminate film of the first laminate film. Provided is an exterior body for an electrochemical device, which is an outer surface seal portion that is bent and bonded so as to overlap an edge of a surface on the exterior side of the exterior body.

  According to such an exterior body for an electrochemical device, at least a part of the seal portion is an outer surface seal portion of the above structure, so that the seal portion is compared with a conventional exterior body provided outside the exterior body. The dead space can be sufficiently reduced. In addition, even when the internal pressure inside the exterior body is increased, the outer surface seal portion having the above structure is less likely to be peeled off because no force is exerted in the direction of expanding the seal portion, and excellent pressure resistance can be obtained.

  It is preferable that the exterior body for electrochemical devices of the present invention has a rectangular outer shape, and at least one of the two sides in contact with the side from which the electrode terminal is led out serves as the outer surface seal portion. The exterior body having such a structure can more effectively obtain the effect of reducing dead space and improving pressure resistance by providing the outer surface seal portion.

  The present invention also provides an exterior body for an electrochemical device according to the present invention, a power generation element and an electrolyte solution housed in a sealed state inside the exterior body, one end connected to each electrode of the power generation element, An electrochemical device comprising: an electrode terminal having an end exposed to the outside of the exterior body. Since such an electrochemical device includes the exterior body having the above-described structure, the dead space is sufficiently reduced and the pressure resistance is excellent.

  ADVANTAGE OF THE INVENTION According to this invention, a dead space can fully be reduced and the exterior body for electrochemical devices which has the sealing structure excellent in pressure | voltage resistance, and an electrochemical device using the same can be provided.

It is a perspective view which shows suitable one Embodiment of the exterior body for electrochemical devices of this invention. It is a front view which shows suitable one Embodiment of the exterior body for electrochemical devices of this invention. It is a perspective view which shows an example of the conventional exterior body for electrochemical devices. It is a schematic cross section which shows an example of the basic composition of the laminate film used as the constituent material of the exterior body for electrochemical devices of this invention. FIG. 2 is a series of process diagrams when the electrochemical device exterior body 1 shown in FIG. 1 is produced. It is a front view which shows suitable one Embodiment of the electrochemical device (lithium ion secondary battery) of this invention. FIG. 7 is a development view when the inside of the lithium ion secondary battery shown in FIG. 6 is viewed from the normal direction of the surface of the anode 10. It is a schematic cross section at the time of cut | disconnecting the lithium ion secondary battery shown in FIG. 6 along the X1-X1 line | wire of FIG. It is a schematic cross section which shows the principal part at the time of cut | disconnecting the lithium ion secondary battery shown in FIG. 6 along the X2-X2 line | wire of FIG.

  Hereinafter, preferred 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 redundant description is omitted. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

  FIG. 1 is a perspective view showing a preferred embodiment of an exterior body for an electrochemical device according to the present invention. As shown in FIG. 1, the exterior body 1 of the present embodiment includes a pair of laminated films 51 and 52 (a first laminated film 51 and a second laminated film 52) facing each other, and the first and second The seal part formed by adhering the edges of the laminate films 51 and 52 is such that the edge of the second laminate film 52 overlaps the edge of the outer surface of the first laminate film 51 on the exterior body. The outer surface seal portion 5 is bent and bonded. The exterior body 1 has a rectangular outer shape, and is formed by bending a single laminate film.

  In the exterior body 1, the side 1 </ b> A shown as the opening in FIG. 1 is a side from which the electrode terminal is derived, and the two sides 1 </ b> B and 1 </ b> C that are in contact with the side are both the outer surface seal portion 5. . Further, the side 1D facing the side 1A of the exterior body 1 is a bent portion, and a pair of laminate films 51 and 52 are continuous. Here, since the side 1D is a bent portion, when the internal pressure inside the exterior body is increased after the electrochemical device is manufactured, the electrolyte solution starts from the corner where the side 1D, the side 1B, and the side 1C of the exterior body 1 are in contact with each other. May leak out. Therefore, it is preferable to seal the corner | angular part with which the edge | side 1D, the edge | side 1B, and the edge | side 1C of the exterior body 1 contact | connect with a heat seal or an adhesive agent. Specifically, as shown in FIG. 2A, the seal portion S is provided only at the corner where the side 1D, the side 1B, and the side 1C contact, or the side 1D as shown in FIG. It is preferable to provide a seal portion S throughout.

  On the other hand, FIG. 3 is a perspective view showing an example of a conventional exterior body in which a seal portion is formed outside the exterior body. As shown in FIG. 3, in the conventional exterior body 4, a seal portion 6 formed by bonding edges of a pair of laminate films 51 and 52 is provided outside the exterior body. In the exterior body 4, the side 4 </ b> A shown as the opening in FIG. 3 is a side from which the electrode terminal is derived, and both the two sides 4 </ b> B and 4 </ b> C in contact with this and the side 4 </ b> D facing the side 4 </ b> A are sealed. It is part 6.

  In the structure of the exterior body 4 shown in FIG. 3, the seal part 6 becomes a dead space. On the other hand, according to the structure of the exterior body 1 shown in FIG. 1, since the seal part is the outer surface seal part 5, the dead space can be sufficiently reduced.

  Further, in the structure of the exterior body 4 shown in FIG. 3, when the internal pressure inside the exterior body increases, a force is applied in the direction of the arrow P in FIG. Works and peels easily. On the other hand, according to the structure of the exterior body 1 shown in FIG. 1, when the internal pressure inside the exterior body increases, no force acts in the direction in which the outer surface seal portion 5 is pushed and spread, so that it is difficult for peeling to occur. High pressure resistance can be obtained.

  As the pair of laminate films 51 and 52 (the first laminate film 51 and the second laminate film 52) constituting the exterior body 1 of the present embodiment, a laminate film having flexibility is used. Since the laminate film is lightweight and can be easily formed into a thin film, the electrochemical device itself can be formed into a thin film. Therefore, the original volume energy density can be easily improved, and the volume energy density based on the volume of the space in which the electrochemical device is to be installed can be easily improved.

  The laminate film is not particularly limited as long as it has flexibility, but it ensures the sufficient mechanical strength and light weight of the exterior body, while moisture and air enter the exterior body from the outside and the exterior. From the viewpoint of effectively preventing the diffusion of electrolyte components from the inside of the body to the outside, the polymer innermost layer that contacts the power generating element to be accommodated, and the side of the innermost layer that contacts the power generating element A laminate composed of three or more layers having at least a metal layer disposed on the opposite side of the metal layer and a polymer layer disposed on the opposite side of the metal layer in contact with the innermost layer. A film is preferred.

  As a laminated structure of the laminate film, for example, a laminate film having a configuration shown in FIG. The laminate film 53 shown in FIG. 4 has an innermost layer 53a made of a polymer that comes into contact with a power generation element housed inside the exterior body on the inner surface F1, and the other surface (outer surface) of the innermost layer 53a. It has a metal layer 53c disposed on top and a polymer outermost layer 53b disposed on the outer surface of the metal layer 53c.

  The innermost layer 53a is a flexible layer, and its constituent material can express the above-mentioned flexibility, and chemical stability with respect to the electrolyte solution accommodated in the exterior body. There is no particular limitation as long as it is a polymer having chemical stability against (chemical reaction, dissolution, and swelling) and oxygen and water (water in the air), but oxygen, water (air) A material having low permeability to the components of the water content and the electrolyte solution is preferable. Examples of the constituent material of the innermost layer 53a include engineering plastics and thermoplastic resins such as polyethylene, polypropylene, polyethylene acid modified products, polypropylene acid modified products, polyethylene ionomers, and polypropylene ionomers.

  The “engineering plastic” means a plastic having excellent mechanical properties, heat resistance, and durability used in mechanical parts, electrical parts, housing materials, etc., for example, polyacetal, polyamide, Examples include polycarbonate, polyoxytetramethyleneoxyterephthaloyl (polybutylene terephthalate), polyethylene terephthalate, polyimide, polyphenylene sulfide, and the like.

  Further, as the constituent material of the outermost layer 53b, the same constituent material as that of the innermost layer 53a may be used. In the exterior body of the present embodiment, since the edge of the second laminate film 52 is bent, the outer surface seal portion 5 has the outer surface of the first laminate film 51 (surface F2 in FIG. 4) and the second laminate. The inner surface of the film 52 (surface F1 in FIG. 4) is bonded. Therefore, when the outer surface seal portion 5 is formed by hot pressing, the surface F1 and the surface F2 of the edge portion can be selectively heat-sealed by adjusting the heating temperature. The constituent material of the layer 53b is preferably a material having a melting point lower than that of the innermost layer 53a. Preferably, the constituent material of the outermost layer 53b includes polypropylene, polyethylene, nylon 6, nylon 11, nylon 12, polybutylene terephthalate (PBT), polyether ether ketone (PEEK), and the like. Among these, polypropylene and polyethylene are particularly preferable because of their extremely low water absorption.

  The metal layer 53c is preferably a layer formed of a metal material having corrosion resistance against oxygen, water (water in the air), and an electrolyte solution. For example, a metal foil made of aluminum, aluminum alloy, titanium, chromium, or the like may be used.

  As a laminate film used for the exterior body of the present embodiment, a laminate having a three-layer structure including an innermost layer 53a made of polyethylene terephthalate, a metal layer 53c made of aluminum, and an outermost layer 53b made of polypropylene. A film is particularly preferred.

  The laminate film 53 having the above-described structure can be produced by using a known production method such as a dry lamination method, a wet lamination method, a hot melt lamination method, or an extrusion lamination method. For example, a film to be a polymer layer constituting the laminate film 53 and a metal foil made of aluminum or the like are prepared. The metal foil can be prepared, for example, by rolling a metal material. Next, a laminate film (multilayer film) 53 is preferably formed by laminating a metal foil on the film to be a polymer layer via an adhesive so as to have a plurality of layers as described above. Is made. The obtained laminate film 53 is used after being cut into a predetermined shape and size.

  Next, the example of the manufacturing method of the exterior body for electrochemical devices mentioned above is demonstrated. FIG. 5A to FIG. 5C are a series of process diagrams when the outer package 1 shown in FIG. 1 is manufactured. First, as shown in FIG. 5A, a single laminate film 50 is prepared. The laminate film 50 is bent at a fold line YY in the drawing. The laminate film 50 has regions of a first laminate film 51 and a second laminate film 52 that are arranged to face each other when folded at a folding line YY. 52B in the figure is an edge portion of the second laminate film 52, and this portion is folded and bonded so as to overlap the outer surface of the edge portion 51B of the first laminate film 51, whereby the outer surface seal portion 5 is bonded. Will be formed. Moreover, 51A and 52A in a figure show the partial area | region which does not form the outer surface sealing part 5 of the 1st and 2nd laminate films 52, respectively.

  Next, as shown in FIG. 5B, the laminate film 50 is folded in half along the fold line YY. Next, as shown in FIG. 5C, the edge 52B of the second laminate film 52 is folded so as to overlap the edge 51B of the outer surface of the first laminate film 51, and the overlapping edges The outer seal portion 5 is formed by bonding the portions 51B and 52B. Then, as shown in FIG. 2, the area | region containing the corner | angular part of the exterior body 1 is sealed as needed. Thereby, the exterior body 1 can be produced.

  In the manufacturing method of the exterior body 1, the bonding method between the overlapping edge portion 51 </ b> B and the edge portion 52 </ b> B is not particularly limited, but for example, a bonding method using heat sealing or a bonding method using an adhesive can be used. From the viewpoint of productivity, it is preferable to use a heat seal method. When bonding by the heat sealing method, for example, a method in which only the edge portions 51B and 52B to be bonded are sandwiched between thin blades, or a plate-like member that does not pass heat is placed inside the exterior body, and the outer surface sealing portion 5 is A method of external pressing (hot pressing) from the forming side can be used. The laminate film 50 has a polymer innermost layer 53a, a metal layer 53c, and a polymer outermost layer 53b as shown in FIG. 4, and the constituent material of the outermost layer 53b. When the melting point of the outermost layer 53a is lower than that of the constituent material of the innermost layer 53a, the whole or a part of the exterior body (for example, the outer surface seal portion 5 is formed from the outside of the first and second laminate films 51 and 52 It is also possible to use a method in which only the overlapping edge portion 51B and edge portion 52B are selectively heat-sealed.

  As mentioned above, although the suitable embodiment of the exterior body for electrochemical devices of this invention was described in detail, the exterior body for electrochemical devices of this invention is not limited to the said embodiment. For example, in the exterior body 1 in the description of the above embodiment, the two sides that contact the side from which the electrode terminal is led out are both outer surface seal portions 5, but one seal portion is the outer surface seal portion 5, and the other side The seal part may be a conventional seal part 6. Moreover, the exterior body of this invention is not limited to the rectangular shape shown in FIG. 1, A cylindrical shape etc. may be sufficient.

  Further, in the exterior body 1 shown in FIG. 1, the first and second laminate films 51 and 52 are formed by bending a single laminate film, but the first laminate film 51 and the second laminate film are formed. A film different from the film 52 may be used. In this case, the bent portion in the exterior body 1 becomes a seal portion, and the entire side 1D is sealed as shown in FIG.

  Next, a preferred embodiment of an electrochemical device using the above-described electrochemical device exterior body will be described. In the present embodiment, a lithium ion secondary battery using the exterior body 1 shown in FIG. 1 as the exterior body will be described.

  FIG. 6 is a front view showing a preferred embodiment of the electrochemical device (lithium ion secondary battery) of the present invention. FIG. 7 is a development view when the inside of the lithium ion secondary battery shown in FIG. 6 is viewed from the normal direction of the surface of the negative electrode 10. Further, FIG. 8 is a schematic cross-sectional view when the lithium ion secondary battery shown in FIG. 6 is cut along line X1-X1 in FIG. 9 is a schematic cross-sectional view showing the main part when the lithium ion secondary battery shown in FIG. 6 is cut along the line X2-X2 of FIG.

  As shown in FIGS. 6 to 9, the lithium ion secondary battery 100 is mainly disposed adjacent to the plate-like negative electrode 10 and the plate-like positive electrode 20 facing each other and between the negative electrode 10 and the positive electrode 20. Plate-like separator 40, an electrolyte solution containing lithium ions, an exterior body 1 containing these in a sealed state, and one end portion of the negative electrode 10 is electrically connected and the other end portion is exterior A negative electrode lead 12 projecting outside the body 1 and a positive electrode lead 22 having one end electrically connected to the positive electrode 20 and the other end projecting outside the exterior body 1. Has been. Hereinafter, details of each component of this embodiment will be described.

  In the present specification, the “negative electrode” is an electrode based on the polarity at the time of discharge of the battery and emits electrons by an oxidation reaction at the time of discharge. Further, the “positive electrode” is an electrode based on the polarity at the time of discharging of the battery and accepts electrons by a reduction reaction at the time of discharging.

  First, the negative electrode 10 and the positive electrode 20 will be described. The negative electrode 10 includes a negative electrode current collector and a negative electrode active material-containing layer formed on the negative electrode current collector. The positive electrode includes a positive electrode current collector and a positive electrode active material-containing layer formed on the positive electrode current collector.

  The negative electrode current collector and the positive electrode current collector are not particularly limited as long as they are good conductors that can sufficiently transfer charges to the negative electrode active material-containing layer and the positive electrode active material-containing layer, and are known lithium ion secondary batteries. The current collector used in the above can be used. For example, the negative electrode current collector and the positive electrode current collector include metal foils such as copper and aluminum, respectively.

  The negative electrode active material-containing layer of the negative electrode 10 is mainly composed of a negative electrode active material and a binder. Note that the negative electrode active material-containing layer preferably further contains a conductive additive.

The negative electrode active material is occlusion and release of lithium ions, desorption and insertion (intercalation) of lithium ions, or doping with lithium ions and counter anions of the lithium ions (for example, PF ₆ ⁻ , ClO ₄ ⁻ ). Any known negative electrode active material can be used without particular limitation as long as it can reversibly proceed with undoping. As such a negative electrode active material, for example, it can be combined with a carbon material such as natural graphite, artificial graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, or lithium such as Al, Si, or Sn. Examples thereof include amorphous compounds mainly composed of oxides such as metals, SiO, SiO ₂ , SiO _x , and SnO ₂ , lithium titanate (Li ₄ Ti ₅ O ₁₂ ), and TiO ₂ .

  As the binder used for the negative electrode 10, known binders can be used without particular limitation. For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene. Copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer Examples thereof include fluororesins such as a polymer (ECTFE) and polyvinyl fluoride (PVF). This binder not only binds constituent materials such as active material particles and conductive assistants added as necessary, but also contributes to binding between the constituent materials and the current collector. Yes.

  In addition to the above, as the binder, for example, vinylidene fluoride-based fluororubber such as vinylidene fluoride-hexafluoropropylene-based fluororubber (VDF-HFP-based fluororubber) may be used.

  In addition to the above, as the binder, for example, polyethylene, polypropylene, polyethylene terephthalate, aromatic polyamide, cellulose, styrene / butadiene rubber, isoprene rubber, butadiene rubber, ethylene / propylene rubber and the like may be used. Also, thermoplastic elastomeric polymers such as styrene / butadiene / styrene block copolymers, hydrogenated products thereof, styrene / ethylene / butadiene / styrene copolymers, styrene / isoprene / styrene block copolymers, and hydrogenated products thereof. May be used. Further, syndiotactic 1,2-polybutadiene, ethylene / vinyl acetate copolymer, propylene / α-olefin (carbon number 2 to 12) copolymer and the like may be used. Further, a conductive polymer may be used.

  It does not specifically limit as a conductive support agent used as needed, A well-known conductive support agent can be used. Examples thereof include carbon blacks, carbon materials, metal powders such as copper, nickel, stainless steel, and iron, mixtures of carbon materials and metal powders, and conductive oxides such as ITO.

  The positive electrode active material-containing layer of the positive electrode 20 is mainly composed of a positive electrode active material and a binder. Note that the positive electrode active material-containing layer preferably further contains a conductive additive.

The positive electrode active material includes insertion and extraction of lithium ions, desorption and insertion of lithium ions (intercalation), or doping and dedoping of lithium ions and a counter anion (for example, ClO ₄ ⁻ ) of the lithium ions. If it can be made to advance reversibly, it will not specifically limit, A well-known electrode active material can be used. For example, lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganese spinel (LiMn ₂ O ₄ ), and the general formula: LiNi _x Co _y Mn _z M _a O ₂ (x + y + z + a = 1, 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, 0 ≦ a ≦ 1, and M is one or more elements selected from Al, Mg, Nb, Ti, Cu, Zn, and Cr) Complex metal oxide, lithium vanadium compound (LiV ₂ O ₅ ), olivine type LiMPO ₄ (where M is one or more elements selected from Co, Ni, Mn, Fe, Mg, Nb, Ti, Al, Zr) Or a composite metal oxide such as lithium titanate (Li ₄ Ti ₅ O ₁₂ ).

  As the binder used for the positive electrode 20, the same binder as that used for the negative electrode 10 can be used. Moreover, as a conductive support agent used for the positive electrode 20 as needed, the same conductive support agent used for the negative electrode 10 can be used.

  The positive electrode current collector of the positive electrode 20 is electrically connected to one end of a positive electrode lead 22 made of, for example, aluminum, and the other end of the positive electrode lead 22 extends to the outside of the exterior body 1. On the other hand, the negative electrode current collector of the negative electrode 10 is also electrically connected to one end of a negative electrode lead 12 made of, for example, copper or nickel, and the other end of the negative electrode lead 12 extends to the outside of the exterior body 1.

  The separator 40 disposed between the negative electrode 10 and the positive electrode 20 is not particularly limited as long as it is formed of a porous body having ion permeability and electronic insulation properties, and is a known lithium ion secondary. The separator used for a battery can be used. For example, a laminate of a film made of polyethylene, polypropylene or polyolefin, a stretched film of a mixture of the above polymers, or a fiber nonwoven fabric made of at least one constituent material selected from the group consisting of cellulose, polyester and polypropylene, etc. It is done.

An electrolyte solution (not shown) is filled in the internal space of the outer package 1, and a part of the electrolyte solution is contained in the negative electrode 10, the positive electrode 20, and the separator 40. As the electrolyte solution, a non-aqueous electrolyte solution in which a lithium salt is dissolved in an organic solvent is used. Examples of the lithium salt include LiPF ₆ , LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CF ₂ SO ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN Salts such as (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiN (CF ₃ CF ₂ CO) ₂ are used. In addition, these salts may be used individually by 1 type, and may use 2 or more types together. Further, the electrolyte solution may be gelled by adding a polymer or the like.

  Moreover, the solvent currently used for the well-known electrochemical device can be used for an organic solvent. For example, propylene carbonate, ethylene carbonate, diethyl carbonate and the like are preferable. These may be used alone or in combination of two or more at any ratio.

  The exterior body 1 has the structure shown in FIG. 1, FIG. 2 (a) and FIG. 5, and the seal portions on the two sides in contact with the sides from which the electrode terminals are led out are the outer surface seal portions 5, and The corner portion on the bent portion side is sealed to form the seal portion S. Further, as shown in FIGS. 6 and 7, the side edges 51a and 52a from which the electrode terminals of the first laminate film 51 and the second laminate film 52 are led out are electrode terminals (the negative electrode lead 12 and the positive electrode 12). It is sealed with the lead 22) interposed therebetween. The negative electrode lead 12 and the first and second laminated films are in the portion of the negative electrode lead 12 that contacts the edge portion 51a of the first laminate film 51 and the seal portion of the edge portion 52a of the second laminate film 52. An insulator 14 for preventing contact with the metal layer is coated. Further, the positive electrode lead 22 and the first and second laminates are formed on the positive electrode lead 22 portion that contacts the seal portion of the edge portion 51 a of the first laminate film 51 and the edge portion 52 a of the second laminate film 52. An insulator 24 for preventing contact with the metal layer in the film is coated.

  The configurations of the insulator 14 and the insulator 24 are not particularly limited, but may be formed of, for example, a polymer. Note that the insulator 14 and the insulator 24 may not be disposed as long as the metal layer in the laminate film can be sufficiently prevented from contacting each of the negative electrode lead 12 and the positive electrode lead 22.

  Next, a method for manufacturing the above-described lithium ion secondary battery 100 will be described.

  The production method of the power generation element 60 (a laminate in which the negative electrode 10, the separator 40, and the positive electrode 20 are sequentially laminated in this order) is not particularly limited, and is a known method that is adopted in the production of a known lithium ion secondary battery. Can be used.

  When the negative electrode 10 and the positive electrode 20 are produced, first, the above-described constituent components are mixed and dispersed in a solvent in which the binder can be dissolved to produce an electrode-forming coating solution (slurry or paste). The solvent is not particularly limited as long as the binder can be dissolved. For example, N-methyl-2-pyrrolidone, N, N-dimethylformamide and the like can be used.

  Next, the electrode forming coating solution is applied onto the surface of the current collector, dried, and rolled to form an active material-containing layer on the current collector, thereby completing the production of the negative electrode 10 and the positive electrode 20. Here, the method for applying the electrode-forming coating solution to the surface of the current collector is not particularly limited, and may be appropriately determined according to the material, shape, and the like of the current collector. Examples of the coating method include a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a gravure coating method, and a screen printing method.

  Thereafter, the negative electrode lead 12 and the positive electrode lead 22 are electrically connected to the prepared negative electrode 10 and positive electrode 20, respectively.

  Next, the separator 40 is disposed between the negative electrode 10 and the positive electrode 20 in a contacted state (preferably in a non-adhered state) to complete the power generation element 60. At this time, it arrange | positions so that the surface by the side of the negative electrode active material content layer of the negative electrode 10 and the surface by the side of the positive electrode active material content layer of the positive electrode 20 may contact with the separator 40.

  On the other hand, the exterior body 1 is manufactured by the manufacturing method described above. As shown in FIGS. 1 and 5, the exterior body 1 is provided with a portion that is not heat sealed in order to secure an opening for introducing the power generation element 60 into the exterior body 1. deep. Thereby, the exterior body 1 in a state having an opening is obtained.

  Then, the power generation element 60 to which the negative electrode lead 12 and the positive electrode lead 22 are electrically connected is inserted into the exterior body 1 having the opening. Then, an electrolyte solution is injected. Subsequently, in a state where a part of the negative electrode lead 12 and the positive electrode lead 22 are respectively inserted into the outer package 1, the opening of the outer package 1 is sealed using a sealing machine. Thereby, the production of the outer package 1 and the lithium ion secondary battery 100 is completed.

  As mentioned above, although the suitable embodiment of the electrochemical device of this invention was described in detail, this invention is not limited to the said embodiment. For example, in the description of the above embodiment, the lithium ion secondary battery 100 including one negative electrode 10 and one positive electrode 20 has been described. However, the negative electrode 10 and the positive electrode 20 are each provided with two or more negative electrodes 10 and 20 positive electrodes. One separator 40 may be always arranged between the two.

  In the description of the above embodiment, the case where the exterior body 1 illustrated in FIG. 1 is used as the exterior body has been described. However, the exterior body is not limited to the exterior body 1 illustrated in FIG. 1. Furthermore, the electrochemical device (lithium ion secondary battery) of the present invention is not limited to the shape shown in FIG. 6, and may be, for example, a cylindrical shape.

  In the description of the above embodiment, the case where the electrochemical device is a lithium ion secondary battery has been described. However, the electrochemical device of the present invention is not limited to a lithium ion secondary battery, and a metallic lithium secondary battery. Secondary batteries other than lithium ion secondary batteries such as batteries, and electrochemical capacitors such as electric double layer capacitors, pseudo-capacitance capacitors, pseudo capacitors, and redox capacitors may be used. In the case of an electrochemical device other than a lithium ion secondary battery, a material suitable for each electrochemical device may be used as the electrode active material. For example, in the case of an electric double layer capacitor, acetylene black, graphite, graphite, activated carbon, or the like is used as an active material contained in the positive electrode active material-containing layer and the negative electrode active material-containing layer.

DESCRIPTION OF SYMBOLS 1 ... Electrochemical device exterior body, 5 ... Outer surface seal part, 10 ... Negative electrode, 12 ... Negative electrode lead, 14 ... Insulator, 20 ... Positive electrode, 22 ... Positive electrode lead, 24 ... Insulator, 40 ... Separator, 50 ... Laminate film, 51 ... First laminate film, 52 ... Second laminate film, 60 ... Power generation element, 100 ... Lithium ion secondary battery.

Claims (3)

An exterior body for accommodating a power generation element of an electrochemical device,
It is composed of a first laminate film and a second laminate film facing each other,
Having a seal part formed by bonding edges of the first and second laminate films;
At least a part of the seal portion is an outer surface seal portion that is bent and bonded so that an edge portion of the second laminate film overlaps an edge portion of the outer surface of the first laminate film. An exterior body for electrochemical devices. The outer shape is rectangular,
The exterior body for an electrochemical device according to claim 1, wherein at least one of two sides in contact with a side from which the electrode terminal is led out serves as the outer surface seal portion. The exterior body for an electrochemical device according to claim 1 or 2,
A power generation element and an electrolyte solution housed in a sealed state inside the exterior body,
One end is connected to each electrode of the power generation element, and the other end is exposed to the outside of the exterior body,
An electrochemical device comprising:

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