JP2008004506A - Nonaqueous electrolyte secondary battery and battery pack as well as manufacturing method of nonaqueous electrolyte secondary battery and battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery and a battery pack which can attain both a control of moisture permeation and improvement of capacity efficiency. <P>SOLUTION: A battery element is housed in a resin frame composed of continuous four sides made of resin material containing a moisture absorbing agent, and an upper surface of the resin frame and an open mouth part of a bottom surface are covered and sealed by an external packaging material to make the nonaqueous electrolyte secondary battery. The battery pack can be obtained by connecting a circuit board housed in a top cover with the above nonaqueous electrolyte secondary battery. The external packaging material can be curved to cover as far as an external wall part and the resin frame can be covered with a film having a high moisture barrier property to control moisture permeation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte secondary battery packaged with a laminate film and a plastic resin frame, a battery pack using the same, and a method for producing the non-aqueous electrolyte secondary battery and the battery pack. The present invention relates to a non-aqueous electrolyte secondary battery capable of improving the discharge capacity by using a technology, a battery pack using the same, a non-aqueous electrolyte secondary battery, and a method for manufacturing the battery pack.

  In recent years, many portable electronic devices such as a camera-integrated VTR (Videotape recorder), a mobile phone, or a laptop computer have appeared, and their size and weight have been reduced. Along with this, the demand for batteries used as power sources for portable electronic devices is growing rapidly, and the battery design is lighter, thinner, and more efficient in the storage space in devices to realize smaller and lighter devices. It is required to use. As a battery satisfying such requirements, a lithium ion battery having a large energy density and output density is most suitable.

  Among them, a battery having a high degree of freedom of shape, a thin and large area sheet type battery, a thin and small area card type battery, and the like are desired. However, in the conventional method using a metal can as an exterior, it is thin. It is difficult to produce a battery.

  In order to solve such problems, a battery in which a substance having a solidifying action is added to an electrolytic solution or a gel electrolyte using a polymer is used and a liquid electrolyte does not exist inside has been studied. In these batteries, the electrode and the electrolyte are in close contact with each other, and the contact state can be maintained. This makes it possible to produce a thin battery using a film-like exterior material such as an aluminum laminate film. Lithium ion polymer secondary batteries have been put into practical use as an example.

  A polymer lithium ion battery has a positive electrode, a negative electrode, and a polymer electrolyte, and has a battery cell configuration in which battery elements each having an electrode terminal derived from the positive electrode and the negative electrode are covered with an exterior film, for example, an aluminum laminate. Further, the battery cell is configured to be housed in a box-shaped mold case including a pair of upper and lower resin cases together with a wiring substrate having a protection circuit, a connection terminal, and the like.

  In this way, conventional polymer batteries are made by covering battery elements and wiring boards covered with aluminum laminate with mold cases consisting of a pair of upper and lower cases, and finally selling them as products to users and the like as battery packs. Was.

  However, the conventional battery pack has the following problems. In the structure of a conventional battery pack that covers a battery cell with a mold case, the thickness of the mold case needs to be about 0.3 mm to 0.4 mm in order to protect the battery cell from an external impact or the like. Therefore, considering the double-sided tape for fixing the battery cell to the mold case and the tolerance at the time of molding the mold case, the thickness of the battery pack is 0.8 mm to 1.0 mm with respect to the thickness of the battery cell. It will increase to a certain extent.

  In addition, in the structure in which the battery cell is covered with a mold case composed of a pair of upper and lower resin cases, when the upper and lower cases are favorably joined by, for example, ultrasonic welding, the joint portion needs to have a thickness of about 0.7 mm. Is done. Therefore, the thickness of the battery pack increases by about 1.4 mm with respect to the thickness of the battery cell. In the case of a battery cell having a thickness of about 4.0 mm, the battery pack is 1.3 times as large as the battery cell. The volume was increased by about 1.4 times.

  Therefore, as in Patent Document 1 below, an integrated structure of a battery and a pack has been proposed in which an exterior material made of a laminate is hardened and used as it is as a battery pack housing.

Japanese Patent Laid-Open No. 2005-166650

  However, in the case of the structure described in Patent Document 1, the battery element is accommodated in the recess formed in the soft laminate film and sealed so that the opening of the recess is covered with the hard laminate film. Since both ends of the film are folded so as to enclose the battery element, the exterior material is provided in an overlapping manner, and the volume ratio of the battery element in the battery is improved as expected. Not in.

  In particular, among the accommodating portions on the electronic device side into which the battery pack is inserted, it is desirable that the exterior material is not provided in an overlapping manner because the clearance of the accommodating portion is small in the thickness direction of the battery pack.

  For such battery packs, for example, a structure in which an element is inserted into a cylindrical outer casing or a structure in which a resin frame or label is wound around a battery of a rectangular metal can has been devised. It was necessary and the volume ratio of the element in the battery was not improved dramatically.

  In addition, as in Patent Document 2 below, a battery in which a battery element is housed in a case composed of a resin frame and a lid member that seals the opening of the resin frame has been proposed.

Japanese Patent Laid-Open No. 10-189055

  In Patent Document 2, an excellent volume efficiency of a battery element can be obtained by a simple structure in which a resin frame and a lid member are directly used as an exterior of a battery.

  However, the resin frame as described above has problems that battery characteristics are deteriorated and gas is generated by allowing moisture to permeate. In order to allow such a resin frame to exhibit a moisture barrier property, it is necessary to seamlessly dispose a metal film or a vapor-deposited film on the entire side surface of the resin frame without a gap even with respect to the cover material, and the cost and productivity are poor. In addition, a deposited film that is relatively easy to install also has a problem in long-term reliability.

  Accordingly, in view of the above-described problems, an object of the present invention is to prevent moisture deterioration by preventing the deterioration of battery characteristics and to have a high volumetric efficiency nonaqueous electrolyte secondary battery, a battery pack using the same, and a nonaqueous An object of the present invention is to provide a method for manufacturing an electrolyte secondary battery and a battery pack.

  In order to solve the above-mentioned problem, a first invention is a non-aqueous solution comprising a battery element including a non-aqueous electrolyte, a resin frame having four continuous sides, and an exterior material formed by laminating a metal layer and a resin layer. An electrolyte secondary battery in which a resin frame has at least one moisture absorption layer, a battery element is accommodated in the resin frame, and an exterior material is provided so as to cover an opening of the resin frame. This is a non-aqueous electrolyte secondary battery.

  The second invention is a battery pack having a battery element including a non-aqueous electrolyte, a resin frame having four continuous sides, an exterior material formed by laminating a metal layer and a resin layer, and a circuit board. The resin frame has at least one moisture absorption layer, the battery element is accommodated in the resin frame, and the non-aqueous electrolyte sealed by providing an exterior material so as to cover the opening of the resin frame. A battery pack in which a secondary battery and a circuit board are electrically connected.

  Further, the third invention comprises a step of molding a resin frame having four continuous sides made of a resin material containing a moisture absorbent, a step of accommodating battery elements in the resin frame, and an opening of the resin frame. A non-aqueous electrolyte secondary battery manufacturing method including a step of sealing a metal layer and a resin layer so as to be covered with an outer packaging material.

  According to a fourth aspect of the present invention, an exterior material formed by laminating a metal layer and a resin layer is inserted into an injection mold, and a resin material containing a moisture absorbent is injected into the exterior material, so that the four sides are continuous. A step of fixing the resin frame integrally, a step of accommodating the battery element in a recess formed by the exterior material and the resin frame, and a step of sealing the opening of the recess so as to be covered with the exterior material. It is a manufacturing method of a nonaqueous electrolyte secondary battery.

  Further, the fifth invention comprises a step of molding a resin frame having four continuous sides made of a resin material containing a moisture absorbent, a step of accommodating battery elements in the resin frame, and an opening of the resin frame. A step of sealing the metal layer and the resin layer so as to be covered with an exterior material, a step of electrically connecting the battery element and the circuit board accommodated in the top cover, and the exterior material and the top And a step of joining the cover.

  Further, the sixth invention includes a step of electrically connecting the battery element and the circuit board accommodated in the top cover to the non-aqueous electrolyte secondary battery manufactured as described above, and the exterior material and the top And a step of joining the cover.

  In the present invention, the moisture intrusion into the battery can be prevented by incorporating the moisture absorbent into the resin frame that houses the battery element.

  Further, by providing such a resin frame integrally with the exterior material in advance, the peel strength between the resin frame and the exterior material can be improved.

  According to the present invention, since water intrusion from the resin frame can be suppressed, battery swelling and deterioration of battery characteristics can be suppressed. In addition, since the non-aqueous electrolyte secondary battery and the battery pack can be manufactured by exposing the resin frame to the outermost part of the battery, it is not necessary to provide an extra exterior material, and the volume efficiency can be improved. .

  An embodiment of the present invention will be described below with reference to the drawings. This time, a battery using a gel electrolyte will be described.

(1) First Embodiment [Configuration of Battery Pack]
FIG. 1 shows a configuration example of a battery pack 1 according to the present invention. The battery pack 1 has an open circuit voltage of about 4.20 V in a fully charged state per pair of positive electrode and negative electrode. Hereinafter, the side on which the top cover 5 is fitted is appropriately referred to as a top portion, and the side facing the top portion is appropriately referred to as a bottom portion.

  In this battery pack 1, a battery element 10 containing a non-aqueous electrolyte is inserted into a resin frame 4 provided on an exterior material 3a made of a laminate film, and an exterior material 3a, another exterior material 3b, The circuit board 6 inserted in the top cover 5 is connected to the nonaqueous electrolyte secondary battery 2 that covers the opening of the resin frame 4 and seals each of the exterior material 3a and the exterior material 3b. It becomes. The resin frame 4 is a resin molded product manufactured by injection molding or the like in a separate process. The electrode terminal 14 led out from the battery element 10 is welded from the inner wall side of the resin frame 4 to the connection terminal 7 made of metal, for example, embedded in the resin frame 4 so as to communicate from the inner wall side to the outer wall side. Connected to. The circuit board 6 is connected to the battery element 10 by resistance welding or ultrasonic welding from the outer wall side of the resin frame 4.

  Hereinafter, the configuration of the battery element 10 will be described.

[Configuration of battery element]
FIG. 2 shows an example of the structure of the battery element 10. This battery element 10 is formed by sequentially laminating a strip-like positive electrode 11, a separator 13a, a strip-like negative electrode 12 disposed opposite to the positive electrode 11, and a separator 13b, and is wound in the longitudinal direction. A gel electrolyte layer (not shown) is formed on both surfaces of the negative electrode 12. From the battery element 10, a positive electrode terminal 14 a connected to the positive electrode 11 and a negative electrode terminal 14 b connected to the negative electrode 12 are derived (hereinafter referred to as an electrode terminal 14 when not referring to a specific terminal).

[Positive electrode]
In the positive electrode, a positive electrode active material layer 11a containing a positive electrode active material is formed on both surfaces of a positive electrode current collector 11b. The positive electrode current collector 11b is made of a metal foil such as an aluminum (Al) foil.

  The positive electrode active material layer 11a includes, for example, a positive electrode active material, a conductive agent, and a binder. Here, the positive electrode active material, the conductive agent, and the binder need only be uniformly dispersed, and the mixing ratio is not limited.

As the positive electrode active material, a metal oxide, a metal sulfide, or a specific polymer can be used depending on the type of the target battery. For example, in the case of constituting a lithium ion battery, Li _x MO ₂ (wherein M represents one or more transition metals, and x varies depending on the charge / discharge state of the battery, and is usually 0.05 or more and 1.10 or less. ) And a composite oxide of lithium and transition metal. As the transition metal constituting the lithium composite oxide, cobalt (Co), Ni, manganese (Mn) or the like is used.

Specific examples of such a lithium composite oxide include LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiNi _y Co _1-y O ₂ (0 <y <1). A solid solution in which a part of the transition metal element is substituted with another element can also be used. Examples thereof include LiNi _0.5 Co _0.5 O ₂ and LiNi _0.8 Co _0.2 O ₂ . These lithium composite oxides can generate a high voltage and have an excellent energy density. Furthermore, TiS _2, MoS _2, may be used NbSe _2, V no lithium metal sulfides such as ₂ O ₅ or an oxide as the positive electrode active material. These positive electrode active materials may be used alone or in combination of two or more.

  As the conductive agent, for example, a carbon material such as carbon black or graphite is used. As the binder, for example, polyvinylidene fluoride, polytetrafluoroethylene, polyvinylidene fluoride, or the like is used. Moreover, as a solvent, N-methyl-2-pyrrolidone (NMP) etc. are used, for example.

[Negative electrode]
In the negative electrode, a negative electrode active material layer 12a containing a negative electrode active material is formed on both surfaces of a negative electrode current collector 12b. The anode current collector 12b is made of a metal foil such as a copper (Cu) foil, a nickel (Ni) foil, or a stainless (SUS) foil.

  The negative electrode active material layer 12a includes, for example, a negative electrode active material, and a conductive agent and a binder as necessary. Here, the negative electrode active material, the conductive agent, and the binder need only be uniformly dispersed, and the mixing ratio is not limited.

As the negative electrode active material, lithium metal, a lithium alloy, a carbon material that can be doped / undoped with lithium, or a composite material of a metal material and a carbon material is used. Specific examples of the carbon material that can be doped / undoped with lithium include graphite, non-graphitizable carbon, and graphitizable carbon. More specifically, pyrolytic carbons, cokes (pitch coke, needle coke, petroleum coke), graphites, glassy carbons, organic polymer compound fired bodies (phenolic resin, furan resin, etc.) at an appropriate temperature. Carbon materials such as those obtained by firing and carbonization), carbon fibers, activated carbon, and the like can be used. Furthermore, as a material capable of doping and dedoping lithium, a polymer such as polyacetylene or polypyrrole or an oxide such as SnO ₂ can be used.

  Various materials can be used as materials capable of alloying lithium, such as tin (Sn), cobalt (Co), indium (In), aluminum (Al), silicon (Si), and these. Often alloys are used. When metallic lithium is used, it is not always necessary to use powder as a coating film with a binder, and a method of pressure bonding a rolled lithium metal foil to a current collector may be used.

  As the binder, for example, polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR) or the like is used. Examples of the solvent include N-methyl-2-pyrrolidone and methyl ethyl ketone.

[Gel electrolyte]
The gel electrolyte is formed by gelling an electrolytic solution with a matrix polymer. As the electrolytic solution, those generally used in lithium ion secondary batteries can be used. As such an electrolytic solution, a nonaqueous electrolytic solution in which an electrolyte salt is dissolved in a nonaqueous solvent can be used.

  Specific examples of the non-aqueous solvent include ethylene carbonate, propylene carbonate, γ-butyrolactone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, ethylpropyl carbonate, or hydrogen of these carbonic acid esters to halogen. Examples include substituted solvents. One of these solvents may be used alone, or a plurality of these solvents may be mixed with a predetermined composition.

Moreover, as an electrolyte salt, it is possible to use the material used for a normal battery electrolyte. Specifically, LiCl, LiBr, LiI, LiClO ₃ , LiClO ₄ , LiBF ₄ , LiPF ₆ , LiNO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , LiSiF _{6 and the} like can be mentioned, but LiPF ₆ and LiBF ₄ are preferable from the viewpoint of oxidation stability. These lithium salts may be used alone or in combination of two or more. There is no problem as long as the lithium salt can be dissolved in the above solvent, but the lithium ion concentration is 0.4 mol / kg or more and 2.0 mol / kg or less with respect to the nonaqueous solvent. Preferably there is.

  As the gel electrolyte, the above-described electrolytic solution is gelled with a matrix polymer. The matrix polymer only needs to be compatible with a non-aqueous electrolyte solution obtained by dissolving the electrolyte salt in the non-aqueous solvent and can be gelled. Examples of such matrix polymers include fluorine polymer compounds such as polyvinylidene fluoride or copolymers with vinylidene fluoride, ether polymer compounds such as polyethylene oxide or a crosslinked product containing polyethylene oxide, polypropylene oxide, Examples thereof include polymers containing acrylonitrile and polymethacrylonitrile in repeating units. Such a polymer may be used individually by 1 type, and may mix and use 2 or more types.

Among them, a fluorine polymer compound is particularly preferable from the viewpoint of redox stability. For example, a copolymer in which hexafluoropropylene is introduced into polyvinylidene fluoride or vinylidene fluoride at a ratio of 75.0% by weight or less can be used. Such polymers have a number average molecular weight in the range of 5.0 × 10 ⁵ to 7.0 × 10 ⁵ (500,000 to 700,000) or a weight average molecular weight of 2.1 × 10 ⁵ to 3. The range is 1 × 10 ⁵ (210,000-310,000), and the intrinsic viscosity is in the range of 1.7 (dl / g) to 2.1 (dl / g).

[Separator]
The separator is made of, for example, a porous film made of a polyolefin-based material such as polypropylene (PP) or polyethylene (PE), or a porous film made of an inorganic material such as a ceramic nonwoven fabric. A porous film in which a resin is mixed and melted or a structure in which two or more porous films are laminated may be used. Among them, polypropylene (PP) and polyethylene (PE) porous films are most effective.

  In general, the thickness of the separator is preferably 5 to 50 μm, more preferably 7 to 30 μm. If the separator is too thick, the amount of the active material filled decreases, the battery capacity decreases, and the ionic conductivity decreases and the current characteristics deteriorate. On the other hand, if the film is too thin, the mechanical strength of the film decreases.

  The battery element 10 configured as described above can be manufactured, for example, as follows.

[Production of positive electrode]
The above-mentioned positive electrode active material, binder and conductive material are uniformly mixed to form a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent to form a positive electrode mixture slurry. Next, this positive electrode mixture slurry is applied by, for example, a doctor blade method. Subsequently, the positive electrode active material layer 11a is formed by drying at high temperature, removing the solvent, and applying pressure. In addition, as a solvent, N-methyl-2-pyrrolidone etc. are used, for example.

  The positive electrode 11 has a positive electrode terminal 14a connected to one end of the positive electrode current collector 11b by spot welding or ultrasonic welding. The positive electrode terminal 14a is preferably a metal foil or a net-like one, but there is no problem even if it is not metal as long as it is electrochemically and chemically stable and can conduct electricity. Examples of the material of the positive electrode terminal 14a include aluminum (Al).

[Production of negative electrode]
The above-described negative electrode active material, conductive material, and binder are uniformly mixed to form a negative electrode mixture, and dispersed in a solvent to form a negative electrode mixture slurry. Next, the negative electrode mixture slurry is uniformly coated on the negative electrode current collector by the same method as that for the positive electrode, and then dried at a high temperature to remove the solvent and pressurize, whereby the negative electrode active material layer 12a is formed.

  Similarly to the positive electrode 11, the negative electrode 12 has a negative electrode terminal 14b connected to one end of the negative electrode current collector by spot welding or ultrasonic welding, and this negative electrode terminal 14b is electrochemically and chemically stable. There is no problem even if it is not metal as long as it can conduct electricity. Examples of the material of the negative electrode terminal 14b include copper and nickel.

  The positive electrode terminal 14a and the negative electrode terminal 14b are preferably derived from the same direction, but there is no problem even if they are derived from any direction as long as no short circuit or the like occurs and there is no problem in battery performance. Moreover, the connection location of the positive electrode terminal 14a and the negative electrode terminal 14b is not limited to the above-described example as long as electrical contact is established.

[Production of battery element]
The gel electrolyte as described above is uniformly applied to both surfaces of the positive electrode 11 and the negative electrode 12 and impregnated in the positive electrode active material layer 11a and the negative electrode active material layer 12a, and then stored at room temperature or subjected to a drying process. Form a layer. Next, the positive electrode 11 and the negative electrode 12 on which the gel electrolyte layer is formed are stacked in the order of the positive electrode 11, the separator 13 a, the negative electrode 12, and the separator 13 b and wound to obtain the battery element 10.

  Next, the non-aqueous electrolyte secondary battery 2 is manufactured using the battery element 10. The nonaqueous electrolyte secondary battery 1 includes a battery element 10, a resin frame 4 that houses the battery element 10, and exterior materials 3 a and 3 b that are joined to the resin frame 4 (hereinafter, unless otherwise specified, appropriately with the exterior material 3. Will be described in detail.

[Exterior material]
FIG. 3A shows the configuration of the exterior material 3 of the present invention. The exterior material 3 has a total thickness of about 130 μm, and includes a metal layer 21 made of a hard metal, an inner resin layer 22 provided on the inner surface of the metal layer 21, and an outer surface of the metal layer. It comprises an exterior layer 23 provided by applying an anchor coat. In addition, the exterior material 3 can also be set as a thinner structure.

  As the metal layer 21, a hard metal material is used, and aluminum, stainless steel, titanium copper, iron plated with any of tin, zinc, nickel, or the like can be appropriately used as a material. Among these, aluminum (Al) and austenitic stainless steel are most suitable, and it is particularly preferable to use aluminum such as 3003H18, 3004H18, 1N30H18 and 5000 series, or austenitic stainless steel such as SUS304.

  Moreover, it is preferable that the thickness of the metal layer 21 is 50 micrometers or more and 100 micrometers or less. If it is less than 50 μm, the hardness required for the exterior of the battery pack cannot be obtained. Moreover, when exceeding 100 micrometers, the volumetric efficiency of the battery element 10 will fall, and battery capacity will be sacrificed.

  As the inner resin layer 22, a resin material having good adhesion to the resin frame 4 to be joined later, for example, polyethylene (PE), polypropylene (PP), ethylene vinyl acetate copolymer, ethylene vinyl acetate alcohol copolymer, ethylene Acrylic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, ethylene / methacrylic acid copolymer, ethylene / methyl methacrylic acid copolymer, ionomer, polyacrylonitrile, polyvinylidene chloride, polytetra Fluoroethylene, polychlorotrifluoroethylene, polyphenylene ether, polyethylene terephthalate hot melt agent, polyamide hot melt agent, and the like can be used, and a resin material containing at least one of these as a main component is used. Among these, it is preferable to use polypropylene (PP) or polyethylene (PE).

  The metal layer 21 and the inner resin layer 22 can be bonded together via an adhesive layer 25. The adhesive layer 25 is an adhesive conventionally used for manufacturing a laminate film such as polyurethane, acrylic, styrene, or the like. An agent can be used. In addition, if a resin material having a thermal bonding effect on a metal is used, it can be directly bonded by a heat roller, and can be bonded by coating a molten or diluted resin material by extrusion or the like. .

  Further, instead of the inner resin layer 22, the inner surface of the metal layer 21 may be primed. Specifically, a nitrogen compound film and an oxide film are formed on the inner surface of the metal layer 21 to improve the adhesion with the resin frame 4.

  As the exterior layer 23, for example, a coating such as a printing layer or a colored layer can be provided. As such, baking coating or ultraviolet (UV) curable coating with excellent abrasion resistance and scratch resistance is desirable.

  Depending on the color of the colored layer, clear laser printing can be obtained by exposing the metal layer 21 by burning the colored portion with a laser. By applying such laser printing, necessary information such as product number can be given without providing a label, so the thickness of the label can be omitted, and the volume efficiency is improved and the battery capacity is reduced. can do. In addition, when performing such laser printing, since the color of the exposed metal layer 21 appears to be floating, it is particularly preferable to make the colored layer dark and dark, but it is also possible to use colors other than dark and dark.

  Further, as shown in FIG. 3B, the exterior material 3 may be provided with an outer resin layer 24 via an adhesive layer 26 on the outer surface of the metal layer 21 without providing the exterior layer 23. The exterior resin layer 24 is made of stretched nylon, stretched polyethylene terephthalate (PET), stretched polyethylene naphthalate (PEN), stretched polybutylene terephthalate (PBT), stretched polybutylene naphthalate (PBN). Stretched polypropylene (PP) and stretched polyethylene (PE) are used, and a resin material containing at least one of them as a main component is used. By providing the exterior resin layer 24 made of a resin such as PET or nylon instead of painting, the nonaqueous electrolyte secondary battery 2 having excellent appearance can be obtained.

  When such an exterior resin layer 24 is provided, it can also be bonded to the metal layer 21 after performing reverse printing on the side surface of the metal layer 21 of the resin film constituting the exterior resin layer 24. By performing such printing, it is not necessary to provide a label, and the nonaqueous electrolyte secondary battery 2 having a surface excellent in abrasion resistance, scratch resistance and designability can be obtained.

  In addition, the exterior resin layer 24 and the metal layer 21 can use an adhesive used for bonding the metal layer 21 and the inner resin layer 22.

  Table 1 below summarizes the components that can be combined and used in the exterior material 3.

  The exterior material 3 includes an exterior material 3a and an exterior material b that respectively cover the opening of the resin frame 4, and the exterior material 3a and the exterior material 3b each have a substantially rectangular shape. The exterior material 3 a and the exterior material 3 b have substantially the same width as the resin frame 4, and the length from the battery top part to the bottom part is several mm to several cm longer than the resin frame 4. This is for joining the top cover 5 containing the circuit board 6 to the portion where the exterior material 3 protrudes from the resin frame 4, and the length is appropriately selected depending on the shape of the top cover 5.

  Further, the shape of the exterior material is not limited to the shape as described above, and for example, shapes as shown in FIGS. 4 to 6 can be used.

In FIG. 4, the exterior material 3 a is bent so as to cover the outer wall portion on the side surface of the resin frame 4. Further, FIG. 5 has a portion where each of the exterior material 3a and the exterior material 3b is bent so as to cover half of the outer wall portion of the side surface of the resin frame 4, and the exterior material 3a and the exterior material 3b are respectively attached to the resin frame 4 By joining to, the outer wall part of the side surface of the resin frame 4 is made to be covered. Further, FIG. 6 is configured such that the single exterior member 3 covers the opening on the top and bottom surfaces of the resin frame 4 and the outer wall portion other than the fitting surface of the top cover 5. Further, the shape of the exterior material 3 is not limited to such a shape, and any shape can be selected without departing from the spirit of the present invention.
[Resin frame]

  The resin frame 4 is a resin frame containing a moisture absorbent provided continuously on four sides as shown in FIG. 1 and is manufactured by injection molding. It is preferable that a connection terminal made of, for example, a metal is provided at a portion of the resin frame 4 facing the lead-out side where the electrode element 14 is led out from the battery element 10. The resin material of the resin frame 4 is polyethylene, polypropylene, ethylene vinyl acetate copolymer, ethylene vinyl acetate alcohol copolymer, ethylene / acrylic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer Copolymer, ethylene / methacrylic acid copolymer, ethylene / methyl methacrylic acid copolymer, ionomer, polyacrylonitrile, polyvinylidene chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyphenylene ether, polyethylene terephthalate hot melt agent, polyamide hot A melt agent or the like may be used alone, or a plurality of types may be mixed and used.

  Among them, a material having low moisture permeability is preferable, and specifically, polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene chloride (PVdC), or the like is preferably used.

  Since the resin frame 4 is later joined to the exterior material 3, a combination having a sealing property with the inner resin layer 22 in consideration of the thermal adhesive strength and reliability with the exterior material 3, for example, the same kind of molecules A combination having a structure is preferred.

Moreover, as a water | moisture-content absorber, highly hydrated materials, such as a sulfate and a polyacrylate, are used individually or in combination of 2 or more types. Specifically, the water absorbent includes sodium sulfate, magnesium sulfate, calcium oxide, calcium chloride, magnesium chloride, sodium nitrate, aluminum oxide, calcium hydride, calcium sulfate, copper sulfate, silicon oxide, magnesium oxide magnesium perchlorate. , Zeolite, diphosphorus pentoxide, calcium carbonate, or a polyacrylate having the general formula (—CH ₂ —CH (COOM) —) _n (where M is selected from Na, K, Mg, Ca) Can be used.

  Such a moisture absorbent is preferably contained in the resin material used for the resin frame in the range of 1.0 wt% to 75.0 wt%. When the moisture absorbent is less than 1.0% by weight, the moisture absorption effect is thin, and moisture may enter the battery and the battery may swell. Further, when the moisture absorbent exceeds 75.0% by weight, the resin frame 4 becomes brittle, cracks and the like enter and moisture enters. For this reason, the moisture permeation into the inside of the battery can be further prevented by containing the moisture absorbent in the range as described above.

  Such a moisture absorbent is preferably melt kneaded in advance in the resin material before molding the resin frame 4.

  Here, Table 2 below summarizes the moisture absorbent used in the resin frame 4 and the resin material of the resin frame 4.

  Further, in order to further prevent moisture intrusion, the resin frame 4 can be coated with a barrier layer having a high moisture barrier property. Such a barrier layer is preferably provided on the outer wall portion or the inner wall portion of the resin frame 4 or on both the outer wall portion and the inner wall portion. Since the upper surface and the bottom surface of the resin frame 4 are joint surfaces with the exterior material 3, no barrier layer is provided.

  As such a barrier layer, for example, by forming an aluminum vapor deposition film, a carbon vapor deposition film, a silicon oxide vapor deposition film, an aluminum oxide vapor deposition film, a polyvinylidene chloride coating film, a layered silicate film, etc., the moisture of the resin frame 4 The deterioration of the absorption effect can be suppressed, and the effect continues.

  7A and 7B are top views of the resin frame 4. Such a resin frame 4 may be entirely formed of a moisture absorbing layer 4a containing a moisture absorbent as shown in FIG. 7A, but as shown in FIG. 7B, for example, an outer layer of the resin frame 4 More preferably, the resin layer 4b does not contain a moisture absorbent, and the moisture absorption layer 4a is provided on the inside of the resin layer 4b. Furthermore, in any of the structures shown in FIGS. 7A and 7B, the water absorption layer 4a may be provided in a plurality of layers instead of a single layer.

  The above-described configuration in which the moisture absorbing layer 4a is provided only on the inner layer of the resin frame is particularly effective in the case of a material in which the resin frame 4 becomes sticky when the moisture absorbent absorbs moisture, for example. When the outer wall surface of the resin frame 4 is exposed on the outer surface of the battery pack 1, the product layer and the handleability can be improved by making the outer layer of the resin frame 4 a resin layer 4b that does not contain a moisture absorbent. it can.

  In addition, when the exterior material 3 or the exterior materials 3a and 3b as shown in FIGS. 4 to 6 are used, a part or all of the outer wall portion of the resin frame 4 exposed on the outer surface of the battery pack is covered. Furthermore, moisture absorption can be prevented.

  At this time, in order to adjust the appearance of the battery pack 1, a convex portion 4 c can be provided on a part of the outer wall portion of the resin frame 4. For example, as shown in FIG. 8, by providing the resin frame 4 with the convex portions 4c so as to be the same height as the thickness of the exterior materials 3a and 3b, and providing the exterior materials 3a and 3b along the convex portions 4c. The outer surface of the battery pack 10 is configured without a step and has an excellent appearance.

  From the viewpoint of preventing moisture from entering the battery, the thicker the resin frame 4 indicated by D in FIG. 7, the greater the moisture absorption amount and the moisture absorption effect. If the thickness is too thick, the battery capacity decreases, which is not preferable. For this reason, it is preferable that the thickness of the resin frame 4 is about 0.5 mm or more and about 1.5 mm in order to achieve both the battery capacity and the moisture intrusion prevention effect. The same applies to the resin frame 4 in which the resin layer 4b not containing the moisture absorbent and the moisture absorbent layer 4a are laminated.

  The connection terminal 7 is provided so as to communicate from the inner wall side of the resin frame 4 to the outer wall side, and electrically connects the battery element 10 and the circuit board 6 via the resin frame 4. Such a connection terminal 7 is made of a material such as a metal that can conduct electricity. For example, a dumbbell-shaped metal terminal 7a as shown in FIG. 9A or a lead-shaped metal piece 7b as shown in FIG. Is molded integrally with the resin frame 4 in advance. The connection terminal 7 is preferably provided also in the case of the resin frame 4 including the resin layer 4b that does not contain a moisture absorbent as shown in FIG. 7B and the moisture absorption layer 4a provided inside the resin layer 4b. .

  When the dumbbell-shaped metal terminal 7a is used, it may be integrally formed so that the metal terminal 7a protrudes as shown in FIG. 9A. Also, as shown in FIG. 9B, the outer wall portion of the resin frame 4 and the metal terminal 7a may be provided continuously without a step.

  Moreover, when using the lead-shaped metal piece 7b as shown in FIG. 10, in order to improve the adhesiveness between the metal piece 7b and the resin frame 4, it is preferable to provide the resin piece 7c on the surface of the metal piece 7b. As such a resin piece 7c, a resin material having good adhesion to a metal can be used. Specifically, maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, and titanate coupling agents are added. Polyethylene, ionomer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene vinyl acetate copolymer and the like to which polyethylene and titanate coupling agents are added can be used.

  Such connection terminals 7 are not necessarily provided, and the electrode terminals 14 of the battery element 10 are led out from the joint surface between the resin frame 4 and the exterior material 3 or the exterior material 3a or 3b, and the circuit board 6 You may connect with. In this case, since the exterior material 3 has the hard metal layer 21, it is not possible to follow the rise of the joint portion from which the electrode terminal 14 is led out when the exterior material 3 and the resin frame 4 are joined. Due to the problem that the adhesiveness between the resin material of the resin frame 4 and the interior layer 32 of the exterior material 3 and the metal of the electrode terminal 14 is low, there is a possibility that it cannot be satisfactorily joined.

  For this reason, as shown in FIG. 11A and FIG. 11B, a resin piece 15 having a good adhesion property to a metal is provided on a part of the electrode terminal 14 sandwiched between the joint portions of the exterior material 3 and the resin frame 4. You may make it improve. Here, the resin piece 15 can use the resin material similar to the material of the resin piece 7c which can be used when using the metal piece 7b as the terminal 7 for a connection.

  Furthermore, in order to improve the strength of the resin frame 4, glass fibers may be mixed in the resin material. 12A and 12B, a metal skeleton 4d can be provided on the outer wall surface of the resin frame 4 and molded integrally with the moisture absorption layer 4a provided on the inner layer of the metal skeleton 4d. When providing the metal skeleton 4d, in addition to providing on the four sides of the resin frame 4 as shown in FIG. 12A, for example, as shown in FIG. 12B, the metal skeleton 4d is arranged on three sides excluding one side corresponding to the top portion, Various configurations such as providing only on the side surface can be used. When the metal skeleton 4d is provided, the height of the metal skeleton 4d is set to be lower than that of the resin frame 4 so that the metal skeleton 4d is not exposed on the top and bottom surfaces of the resin frame 4. This is because the top and bottom surfaces of the resin frame 4 are for joining the exterior materials 3a and 3b.

  The nonaqueous electrolyte secondary battery 2 having the above-described configuration can be manufactured, for example, as follows.

[Production of non-aqueous electrolyte secondary battery]
First, the electrode terminal 14 led out from the battery element 10 is connected to the inner surface side of the resin frame 4 of the connection terminal 7 provided integrally with the resin frame 4 by, for example, resistance welding or ultrasonic welding. Is accommodated in the resin frame 4. Next, the exterior materials 3 a and 3 b are disposed on the bottom and top surfaces of the resin frame 4 to cover the opening of the resin frame 4. Further, the non-aqueous electrolyte secondary battery 2 is manufactured by sealing the resin frame 4 and the exterior materials 3a and 3b by performing heat fusion under reduced pressure using a heater block made of metal, for example.

  At this time, as shown in FIG. 13, the outer laminates 3 a and 3 b may be further provided after the soft laminate film 16 is once joined to the opening of the resin frame 4 in which the battery element 10 is accommodated. The electrode terminal 14 led out from the battery element 10 is connected to the inner surface side of the resin frame 4 of the connection terminal 7 so that the battery element 10 is accommodated in the resin frame 4 and then the opening of the resin frame 4 is covered. A soft laminate film 16 is provided, and four sides of the soft laminate film 16 are heat-sealed under reduced pressure and sealed. Next, the outer packaging materials 3a and 3b are arranged from the outside of the soft laminate film 16, and joined by heat fusion or an adhesive, whereby the nonaqueous electrolyte secondary battery 2 is manufactured.

  As the soft laminate film 16, a laminate film having a configuration shown in FIG. 14 can be used. The soft laminate film 16 has a moisture-proof, insulating structure in which a metal layer denoted by reference numeral 31 is sandwiched between an interior layer 32 and an exterior layer 33 made of resin layers provided on the inner surface and the outer surface of the metal layer 31, respectively. It consists of a multilayer film having properties.

  The metal layer 31 is made of a soft metal material, and aluminum is most preferable from the viewpoint of lightness, extensibility, price, and ease of processing. In particular, aluminum such as 8021O or 8079O is preferably used. Further, the metal layer 31 and the exterior layer 33 and the metal layer 31 and the interior layer 32 are bonded to each other through adhesive layers 34 and 35, and the adhesive layer 34 may be omitted as necessary.

  The exterior layer 33 is preferably made of a resin material having good adhesiveness with the exterior materials 3a and 3b. For example, the same material as that of the inner resin layer 22 can be used. Moreover, when bonding the exterior materials 3a and 3b with an adhesive, the exterior layer 33 is not necessarily required.

  Further, since the interior layer 32 is melted by heat or ultrasonic waves and joined to the resin frame 4, it is preferable to use a resin material having good adhesion to the resin frame 4. Specifically, the same material as the inner resin layer 22 of the exterior material 3 can be used in the same manner as the exterior layer 33.

  Hereinafter, a method for producing the battery pack 1 will be described.

[Battery pack]
The battery pack 1 can be produced by connecting the circuit board 6 to the nonaqueous electrolyte secondary battery 2. The circuit board 6 is accommodated in the top cover 5, and terminals 6 a connected to the circuit board 6 are led out from the top cover 5.

[Circuit board]
The circuit board 6 is mounted with a protection circuit including a temperature protection element such as a fuse, a PTC (Positive Temperature Coefficient), a thermistor, an ID resistor for identifying the battery pack, and a plurality of, for example, 3 Contact points are formed. Further, the protection circuit includes an IC (Integrated Circuit) for monitoring the secondary battery and controlling an FET (Field Effect Transistor), and a charge / discharge control FET.

  The PTC is connected in series with the battery element 10, and when the temperature of the battery element 10 becomes higher than the set temperature, the electrical resistance increases rapidly and substantially blocks the current flowing through the battery. A fuse and a thermistor are also connected in series with the battery element 10, and when the temperature of the battery element 10 becomes higher than the set temperature, the current flowing through the battery is cut off. Further, an IC for monitoring the battery element 10 and controlling the FET, and a protection circuit including the charge / discharge control FET may be in a dangerous state such as heat generation or ignition if the terminal voltage of the battery element 10 increases excessively. Therefore, the voltage of the battery element 10 is monitored, and if the voltage exceeds a specified voltage, the charge control FET is turned off to prohibit charging. When the terminal voltage of the battery element 10 is overdischarged to below the discharge prohibition voltage and the secondary battery voltage becomes 0V, the battery element 10 may be in an internal short circuit state and may not be recharged, so the secondary battery voltage is monitored. If the voltage falls below the discharge inhibition voltage, the discharge control FET is turned off to inhibit discharge.

[Top cover]
The top cover 5 is fitted into the top side opening of the nonaqueous electrolyte secondary battery 2 to close the top side opening. The top cover 5 is provided with an opening 8, and the contact portion of the circuit board 6 accommodated in the top cover 5 is held horizontally through the opening 8 so as to face the outside of the battery pack 1. ing.

  Such a top cover 5 is, for example, a resin molded product manufactured by injection molding or the like in another process. For example, a holder that fits the top cover 5 is provided, and the circuit board 6 is held by fitting the holder. It may be.

  Alternatively, the non-aqueous electrolyte secondary battery may be molded integrally by placing it in a mold and injecting hot melt resin. In this case, it is necessary to suppress damage to the circuit board 6 due to heat.

[Production of battery pack]
A circuit board 6 is accommodated in such a top cover 5. A terminal 6 a connected to the circuit board 6 is led out from the top cover 5, and the terminal 6 a is connected to the outer surface side of the resin frame 4 of the connection terminal 7 provided integrally with the resin frame 4, for example, resistance welding or ultrasonic waves. Connected by welding. Furthermore, after fitting the top cover 5 into the top side opening of the nonaqueous electrolyte secondary battery 2 so that the terminal 6a is folded, the top cover 5 and the exterior materials 3a and 3b are heat-sealed using a heater block. By doing so, the battery pack 1 is produced.

  Thereafter, hot melt resin or adhesive is injected into the space between the top cover 5 and the resin frame 4 as necessary so that the joint between the nonaqueous electrolyte battery 2 and the top cover 5 becomes stronger. Good. The hot melt resin to be filled is not particularly limited as long as it has a low viscosity state at the time of injection. For example, polyamide hot melt, polyolefin hot melt, nylon, polypropylene (PP), polycarbonate (PC) ABS (Acrylonitrile-Butadiene-Styrene) resin or the like can be used.

  In such a case, an inlet is provided in the top cover 5 in advance so that hot melt resin or adhesive can be injected from the inlet. In addition, when two or more injection ports are provided, it serves as an injection port and an air vent hole for extracting the air in the space between the top cover 5 and the resin frame 4, so that the details are filled and bonded. It is possible to improve the properties.

  Further, it is also preferable to provide a protrusion having a substantially L-shaped cross section, a substantially T-shaped cross section, or the like on a part of the top cover 5 facing the resin frame 4. When the hot melt resin or adhesive is cured, a so-called anchor effect can be obtained, and the bonding strength of the top cover 5 can be further improved.

  The battery pack 1 using the non-aqueous electrolyte secondary battery 2 and the non-aqueous electrolyte battery 2 manufactured as described above has a very high volumetric efficiency of the battery element 10 and suppresses moisture intrusion into the battery. A decrease in battery characteristics can be suppressed.

(2) Second Embodiment A second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the battery pack 1 in which the resin frame 4 is integrally molded on the exterior material 3 in advance will be described. In FIG. 15 and FIG. 16 used below, the same reference numerals are given to the same or corresponding parts as the battery pack 1 and the members constituting the battery pack 1 shown in FIG.

[Battery pack configuration]
As shown in FIG. 15, in this battery pack 1, a battery element 10 containing a non-aqueous electrolyte is inserted into a resin frame 4 provided in advance by integral molding on an exterior material 3a made of a laminate film. The circuit board 6 inserted in the top cover 5 is connected to the non-aqueous electrolyte secondary battery 2 in which the opening of the resin frame 4 is covered with 3b and each of the exterior material 3a and the exterior material 3b is sealed. Being done. Only differences from the first embodiment will be described below.

[Configuration of battery element]
The battery element 10 can be the same as that used in the first embodiment.

  Moreover, you may comprise the battery pack 1 so that the open circuit voltage in a fully charged state per a pair of positive electrode and negative electrode may have a high charging voltage of about 4.25V or more and 4.6V or less. The battery element 10 that realizes the battery pack 1 having a high charging voltage is configured as follows.

[Positive electrode]
As the positive electrode active material, for example, one or more positive electrode active materials capable of inserting and extracting lithium can be used. As the positive electrode active material capable of inserting and extracting lithium, for example, lithium-containing transition metal compounds such as lithium oxide, lithium phosphorus oxide, and lithium sulfide are suitable. In order to increase the energy density, a lithium-containing transition metal oxide containing lithium, a transition metal element, and oxygen (O) is preferable. Among them, as the transition metal element, cobalt (Co), Ni, manganese (Mn), and iron It is more preferable if it contains at least one of the group consisting of (Fe). Examples of such a lithium-containing transition metal compound include a lithium-containing transition metal oxide having a layered rock-salt structure shown in Chemical Formula 1 below and a lithium composite phosphate having an olivine-type structure shown in Chemical Formula 2 below. Specific examples include LiNi _0.50 Co _0.20 Mn _0.30 O ₂ , LiCoO ₂ , LiNiO ₂ , LiNi _c Co _1-c O ₂ (0 <c <1), LiMn ₂ O _4, LiFePO _{4, and the} like. is there.

Formula _{1] Li p Ni (1-} qr) Mn q M1 r O (2-y) X z
In the formula, M1 represents at least one element selected from Groups 2 to 15 excluding Ni and Mn, and X represents at least one element selected from Group 16 elements and Group 17 elements other than oxygen (O). p, q, y and z are 0 ≦ p ≦ 1.5, 0 ≦ q ≦ 1.0, 0 ≦ r ≦ 1.0, −0.10 ≦ y ≦ 0.20, 0 ≦ z ≦ 0.2 It is a value within the range.

[Formula 2] Li _a M2 _b PO ₄
In the formula, M2 represents at least one element selected from Groups 2 to 15. a and b are values within the range of 0 ≦ a ≦ 2.0 and 0.5 ≦ b ≦ 2.0.

  As the conductive agent, for example, a carbon material such as carbon black or graphite is used. As the binder, for example, polyvinylidene fluoride, polytetrafluoroethylene or the like is used.

  The negative electrode 12, the separator 13, the gel electrolyte, and the like can use the same materials as those in the first embodiment.

  By using the battery element 10 manufactured using such a positive electrode material, the capacity of the positive electrode active material that has not been used so far can be utilized by increasing the charging voltage compared to the conventional 4.20 V. it can. That is, the amount of lithium released per unit mass of the positive electrode active material is increased and occluded in the negative electrode active material, so that the capacity and energy density can be increased.

  Further, as shown in FIG. 16, the positive electrode 11 and the negative electrode 12 on which the gel electrolyte layer is formed are laminated in the order of the positive electrode 11, the separator 13a, the negative electrode 12, and the separator 13b and wound to form a wound electrode body, and then laminated. The battery element 10 may be packaged with the film 17.

  As the laminate film 17, it is preferable to use a soft laminate film capable of forming the accommodating portion 17 a that accommodates the wound electrode body. The laminate film 17 has the same configuration as that shown in FIG. 14, and the metal layer is sandwiched between an interior layer and an exterior layer, which are resin layers respectively provided on the inner side surface and the outer side surface of the metal layer. It consists of a multilayer film having

  A soft metal material is used for the metal layer, and specifically, the same material as that of the metal layer 31 can be used.

  The interior layer 32 is a part that is melted by heat or ultrasonic waves and fused to each other, and has a low density other than polyethylene (PE), non-axially oriented polypropylene (CPP), polyethylene terephthalate (PET), nylon (Ny). Polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE) can be used, and a plurality of types can be selected and used.

  For the exterior layer, polyolefin-based resin, polyamide-based resin, polyimide-based resin, polyester, or the like is used because of its beautiful appearance, toughness, and flexibility. Specifically, nylon (Ny), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polybutylene naphthalate (PBN) are used. Is also possible.

  As shown in FIG. 16, the laminate film 17 forms an accommodating portion 17a by deep drawing, and after the wound electrode body is accommodated in the accommodating portion 17a, the laminate film 17 is folded back so that the laminate film 17 opens the opening of the accommodating portion 17a. Cover the part. Next, the battery element 10 is formed by sealing the three sides excluding the folded side around the wound electrode body by heat-sealing under reduced pressure.

  At this time, the positive electrode terminal 14 a is preferably provided with a sealant 18 made of a resin piece at a portion facing the sealing portion of the laminate film 17 in order to improve the adhesion to the laminate film 17. As such a resin piece, a resin material having a relatively high adhesiveness to a metal, such as polyethylene modified with maleic anhydride and polypropylene modified with maleic anhydride, is used.

  Further, when such a sealant 18 is not used, it is preferable to perform, for example, primer processing on the surface of the positive electrode terminal 14a. Primer processing is, for example, surface roughening by plasma treatment, chemical conversion treatment, chromate treatment, sand blasting, alumite treatment or the like.

  Moreover, also about the negative electrode terminal 14b, it is preferable to improve the adhesiveness with the laminate film 17 by providing the sealant 18 or carrying out primer processing similarly to the positive electrode terminal 14a.

  In the case of the battery element 10 that is manufactured by being packaged with the laminate film 17, an electrolytic solution can also be used. In the case of such a battery element 10, an electrolytic solution is injected when the battery element 10 is covered with the laminate film 17. First, after heat-sealing the two sides of the electrode body excluding the folded side, a predetermined amount of electrolytic solution is injected from the remaining opening, and finally the opening is heat-sealed, whereby the battery Element 10 is obtained.

[Configuration of non-aqueous electrolyte secondary battery]
The nonaqueous electrolyte secondary battery 2 is provided with a resin frame 4 in advance by integral molding on an exterior material 3a, and the battery element 10 that is exteriorized with a laminate film 17 is accommodated in the resin frame 4, and the exterior material 3b is made of resin. It is produced by sealing the opening of the frame 4. Note that the exterior materials 3a and 3b can be the same as those in the first embodiment, and thus the description thereof is omitted.

[Resin frame]
The resin frame 4 is molded integrally on the exterior material 3a so that four sides are continuously provided by placing the exterior material 3a in an injection mold and injecting a resin material containing a moisture absorbent. It has been made. In addition, the material similar to 1st Embodiment can be used for the material of the resin frame 4 and a moisture absorber.

  Such a resin frame 4 can be provided with a barrier layer made of, for example, an aluminum vapor deposition film on the outer wall portion or the inner wall portion of the resin frame 4 or both the outer wall portion and the inner wall portion as required.

  Alternatively, the outer layer of the resin frame 4 may be configured as a resin layer 4b that does not contain a moisture absorbent, and the inner layer may be configured as the moisture absorbing layer 4a. In such a case, first, a resin material that does not contain a moisture absorbent is injected onto the exterior material 3a disposed in the injection mold to form the resin layer 4b, and then the moisture inside the resin layer 4b. The resin frame 4 is formed by injecting a resin material containing an absorbent to form the moisture absorption layer 4a. When a plurality of moisture absorption layers 4a are provided, layer formation is performed a plurality of times by injection of a resin material containing a moisture absorbent.

  Further, the resin frame 4 is provided with a connection terminal 7 provided so as to communicate from the inner wall side to the outer wall side of the resin frame 4 and electrically connecting the battery element 10 and the circuit board 6 via the resin frame 4. It may be provided integrally. The connection terminal 7 is preliminarily disposed in an injection mold together with the exterior material 3a, and is molded integrally with the resin frame 4 by injecting a resin material.

  In addition, as shown in FIG. 15, when the exterior material 3a is disposed so as to cover the outer wall surface of the resin frame 4 by bending the blank portion, the resin material 4 is injected and the resin frame 4 is molded. It is preferable because it improves the service life of the battery. Further, the resin frame 4 may be integrally formed on the exterior material 3 as shown in FIG.

  The nonaqueous electrolyte secondary battery 2 having the above-described configuration can be manufactured, for example, as follows.

[Production of non-aqueous electrolyte secondary battery]
The electrode terminal 14 led out from the battery element 10 is connected to the resin frame 4 molded integrally with the exterior material 3a as described above by, for example, resistance welding or ultrasonic welding. Next, the non-aqueous electrolyte secondary battery 2 is obtained by housing the battery element 10 in the resin frame 4 and disposing the exterior material 3b on the upper surface of the resin frame 4 and sealing it by heat sealing.

[Production of battery pack]
A top cover 5 containing a circuit board 6 is connected to the nonaqueous electrolyte secondary battery 2 as described above, and the top cover 5 is fitted into the top side opening. Furthermore, the battery pack 1 is manufactured by joining the exterior materials 3a and 3b and the top cover 5 by heat sealing.

  In addition, since the manufacturing process of the circuit board 6, the top cover 5, and the battery pack is the same as that of the first embodiment, detailed description thereof is omitted.

  In this way, by producing the battery pack 1 using the resin frame 4 that is integrally formed on the exterior material 3, moisture intrusion is prevented, volume efficiency is improved, and bonding strength is excellent. An endurable battery pack 1 can be produced.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

(1) Example 1
Battery packs are prepared by changing the amount of moisture absorbent added, and battery swelling is evaluated for each battery pack. Hereinafter, a method for manufacturing the battery pack will be described.

<Example 1-1>
[Production of positive electrode]
A positive electrode mixture was prepared by uniformly mixing 92% by weight of lithium cobaltate (LiCoO ₂ ), 3% by weight of powdered polyvinylidene fluoride and 5% by weight of powdered graphite, and this was dispersed in N-methylpyrrolidone. Thus, a positive electrode mixture slurry was obtained. This positive electrode mixture slurry was uniformly applied on both surfaces of an aluminum (Al) foil serving as a positive electrode current collector, and dried under reduced pressure at 100 ° C. for 24 hours to form a positive electrode active material layer.

  Subsequently, this was pressure-formed by a roll press machine to obtain a positive electrode sheet, the positive electrode sheet was cut into a strip shape to form a positive electrode, and an aluminum (Al) ribbon lead was welded to an uncoated portion of the active material.

[Production of negative electrode]
A negative electrode mixture was prepared by uniformly mixing 91% by weight of artificial graphite and 9% by weight of powdered polyvinylidene fluoride, and dispersed in N-methylpyrrolidone to obtain a negative electrode mixture slurry. Next, this negative electrode mixture slurry was uniformly applied to both surfaces of a copper (Cu) foil serving as a negative electrode current collector, and dried under reduced pressure at 120 ° C. for 24 hours to form a negative electrode active material layer.

  Next, this was pressure-formed by a roll press machine to obtain a negative electrode sheet, the negative electrode sheet was cut into a strip shape to form a negative electrode, and a nickel (Ni) ribbon lead was welded to an uncoated portion of the negative electrode active material.

[Production of gel electrolyte]
A polyvinylidene fluoride copolymerized with 6.9% by weight of hexafluoropropylene, a nonaqueous electrolytic solution, and dimethyl carbonate (DMC) as a diluting solvent are mixed, stirred and dissolved to obtain a sol electrolyte solution. Got. The electrolyte was prepared by mixing ethylene carbonate (EC) and propylene carbonate (PC) at a weight ratio of 6: 4 and dissolving 0.8 mol / kg LiPF ₆ and 0.2 mol / kg LiBF ₄ . The mixing ratio was a weight ratio of polyvinylidene fluoride: electrolyte: DMC = 1: 6: 12. Next, the obtained sol-form electrolyte solution was uniformly applied on both the positive electrode and the negative electrode. Then, it was made to dry at 50 degreeC for 3 minute (s), the solvent was removed, and the gel electrolyte layer was formed on both surfaces of the positive electrode and the negative electrode.

[Production of battery element]
Next, a battery element was obtained by winding a belt-like positive electrode having a gel electrolyte layer formed on both sides and a belt-like negative electrode having a gel electrolyte layer formed on both surfaces in the longitudinal direction via a separator. As the separator, a porous polyethylene film having a thickness of 10 μm and a porosity of 33% was used.

[Resin frame]
As a resin frame that accommodates the battery element, a resin material in which 0.10% by weight of magnesium sulfate as a water absorbent is mixed with polypropylene (PP) is used, and only one moisture absorption layer is formed in advance by separate injection molding. Thus, a resin frame having a frame thickness of 1.0 mm was produced. A dumbbell-shaped connection terminal was integrally formed on one side corresponding to the battery top portion of the resin frame.

[Exterior material]
As the exterior material, SUS304 having a thickness of 100 μm was used as a metal layer, and a polypropylene (PP) film having a thickness of 30 μm was used as an inner resin layer, and these were bonded together with an adhesive. Further, the outer surface of the metal layer was subjected to ultraviolet (UV) curing coating to obtain an exterior material. The outer shape of the exterior material is the same as the dimensions of the bottom and top surfaces of the resin frame.

[Production of battery pack]
A battery element is housed in the resin frame described above, and an exterior material is disposed so as to cover the bottom and top openings of the resin frame, respectively, and sealed by thermal fusion under reduced pressure to provide a nonaqueous electrolyte secondary battery It was. Furthermore, after the circuit board accommodated in the top cover was fitted into the top side opening of the nonaqueous electrolyte secondary battery, the exterior material and the top cover were thermally fused to produce a battery pack.

<Example 1-2>
A battery pack was produced in the same manner as in Example 1-1 except that the amount of the water absorbent added was 0.50% by weight.

<Example 1-3>
A battery pack was produced in the same manner as in Example 1-1 except that the amount of the water absorbent added was 1.0% by weight.

<Example 1-4>
A battery pack was produced in the same manner as in Example 1-1 except that the amount of the water absorbent added was 5.0% by weight.

<Example 1-5>
A battery pack was produced in the same manner as in Example 1-1 except that the addition amount of the moisture absorbent was 10.0% by weight.

<Example 1-6>
A battery pack was produced in the same manner as in Example 1-1 except that the addition amount of the moisture absorbent was 25.0% by weight.

<Example 1-7>
A battery pack was produced in the same manner as in Example 1-1 except that the amount of the moisture absorbent added was 50.0% by weight.

<Example 1-8>
A battery pack was produced in the same manner as in Example 1-1 except that the addition amount of the moisture absorbent was 75.0% by weight.

<Example 1-9>
A battery pack was produced in the same manner as in Example 1-1 except that the addition amount of the moisture absorbent was 80.0% by weight.

<Comparative Example 1-1>
A battery pack was produced in the same manner as in Example 1-1 except that the moisture absorbent was not added.

[Evaluation of battery swelling]
For each of these battery packs, constant current charging is performed at a charging current of 800 mA, switching to constant voltage charging when the charging voltage reaches 4.35 V, and then charging is performed when the total charging time is 1 hour. finished. Thereafter, constant current discharge at 800 mA was performed, and the process was terminated when the battery voltage reached 3.7V.

  The battery packs of Examples and Comparative Examples charged in this manner were stored in an atmosphere at an air temperature of 25 ° C. and a relative humidity of 55%, and the number of days when the swelling of the battery pack was 0.5 mm or more was examined. The maximum storage period is 2 years.

  Table 3 below shows the results of evaluation of battery swelling. For battery packs whose battery bulge is less than 0.5 mm when two years have passed since the start of battery storage, the number of days that the battery pack bulges is indicated as “over 2 years”.

  As can be seen from Table 3, by adding a moisture absorbent to the resin frame, moisture intrusion into the battery and battery swelling associated therewith can be suppressed. Moreover, the addition amount of the moisture absorbent is more preferably 0.10 wt% or more and 75.0 wt% or less, and further preferably 5.0 wt% or more and 75.0 wt% or less.

(2) Example 2
Battery packs are produced by changing the type of moisture absorbent, and battery swelling is evaluated for each battery pack.

<Example 2-1>
A battery pack was produced in the same manner as in Example 1-1 except that magnesium chloride was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-2>
A battery pack was produced in the same manner as in Example 1-1 except that sodium nitrate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-3>
A battery pack was produced in the same manner as in Example 1-1 except that sodium polyacrylate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-4>
A battery pack was produced in the same manner as in Example 1-1 except that potassium polyacrylate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-5>
A battery pack was produced in the same manner as in Example 1-1 except that magnesium acrylate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-6>
A battery pack was produced in the same manner as in Example 1-1 except that calcium polyacrylate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-7>
A battery pack was produced in the same manner as in Example 1-1 except that sodium sulfate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-8>
A battery pack was produced in the same manner as in Example 1-1 except that calcium oxide was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-9>
A battery pack was produced in the same manner as in Example 1-1 except that calcium chloride was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-10>
A battery pack was produced in the same manner as in Example 1-1 except that aluminum oxide was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-11>
A battery pack was produced in the same manner as in Example 1-1 except that calcium hydride was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-12>
A battery pack was produced in the same manner as in Example 1-1 except that calcium sulfate was used as the water absorbent and the addition amount was 50.0% by weight.

<Example 2-13>
A battery pack was produced in the same manner as in Example 1-1 except that copper sulfate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-14>
A battery pack was produced in the same manner as in Example 1-1 except that silicon oxide was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-15>
A battery pack was produced in the same manner as in Example 1-1 except that magnesium oxide was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-16>
A battery pack was produced in the same manner as in Example 1-1 except that magnesium perchlorate was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-17>
A battery pack was produced in the same manner as in Example 1-1 except that zeolite was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-18>
A battery pack was produced in the same manner as in Example 1-1 except that diphosphorus pentoxide was used as the moisture absorbent and the addition amount was 50.0% by weight.

<Example 2-19>
A battery pack was produced in the same manner as in Example 1-1 except that calcium carbonate was used as the moisture absorbent and the addition amount was 50.0% by weight.

[Evaluation of battery swelling]
About each such battery pack, charging / discharging and preservation | save were performed on the conditions similar to Example 1, and the number of days when the swelling of a battery pack will be 0.5 mm or more was investigated. The maximum storage period is 2 years.

  Table 4 below shows the results of evaluation of battery swelling. For battery packs whose battery bulge is less than 0.5 mm when two years have passed since the start of battery storage, the number of days that the battery pack bulges is indicated as “over 2 years”.

  As can be seen from Table 4, even in the case of using the resin frame to which the moisture absorbents of Examples 2-1 to 2-19 were added in addition to magnesium sulfate, the resin frame can be used for a long period of time. Water intrusion into the battery and battery swelling associated therewith can be suppressed.

(3) Example 3
Battery packs are manufactured by changing the configuration of the exterior material and the resin frame, and the strength against dropping of each battery pack is measured.

<Example 3-1>
A battery was prepared in the same manner as in Example 1-1 except that aluminum 3003H18 was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A pack was made.

<Example 3-2>
A battery as in Example 1-1, except that aluminum 3004H18 was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A pack was made.

<Example 3-3>
A battery was prepared in the same manner as in Example 1-1 except that aluminum 500H18 was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A pack was made.

<Example 3-4>
Battery as in Example 1-1, except that aluminum 1N30H18 was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A pack was made.

<Example 3-5>
Battery pack as in Example 1-1, except that SUS304 was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. Was made.

<Example 3-6>
Battery pack as in Example 1-1, except that titanium was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. Was made.

<Example 3-7>
Example 1-1, except that galvanized iron was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A battery pack was produced.

<Example 3-8>
Battery as in Example 1-1 except that tin-plated iron was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A pack was made.

<Example 3-9>
Example 1-1, except that nickel-plated iron was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. A battery pack was produced.

<Example 3-10>
Battery pack as in Example 1-1, except that copper was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. Was made.

<Example 3-11>
Battery pack as in Example 1-1, except that copper was used as the metal layer, polyethylene (PE) was used as the inner resin layer, and polypropylene (PP) added with 50.0 wt% magnesium sulfate was used as the resin frame. Was made.

<Example 3-12>
Example except that copper was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and polypropylene (PP) added with 50.0% by weight magnesium sulfate and 30.0% by weight glass fiber was used as the resin frame. A battery pack was produced in the same manner as in 1-1.

<Example 3-13>
Copper is used as the metal layer, polypropylene (PP) is used as the inner resin layer, and polypropylene (PP) added with 50.0% by weight of magnesium sulfate is used as the resin frame. A battery pack was produced in the same manner as in Example 1-1 except that the ends of the battery were bent to cover both sides of the battery pack.

<Example 3-14>
Copper is used as the metal layer, polypropylene (PP) is used as the inner resin layer, polypropylene (PP) to which 50.0% by weight of magnesium sulfate is added is used as the resin frame, one end of the exterior material is bent, and A battery pack was produced in the same manner as in Example 1-1 except that a resin frame was produced by integral molding to cover both sides of the battery pack.

<Example 3-15>
Example 1-1, except that the inner resin layer was not provided, copper whose primer was treated on the inner surface was used as the metal layer, and polypropylene (PP) added with 50.0% by weight of magnesium sulfate was used as the resin frame. A battery pack was produced in the same manner.

<Example 3-16>
Copper was used as the metal layer, polypropylene (PP) was used as the inner resin layer, and 50.0% by weight of magnesium sulfate was added to the inside of the aluminum (Al) formed in a U shape on the bottom and both sides as the resin frame. A battery pack was produced in the same manner as in Example 1-1 except that a frame provided with a moisture absorption layer made of polypropylene (PP) was used.

[Evaluation of drop strength]
About each such battery pack, after charging / discharging on the conditions similar to Example 1, the battery was dropped from the point of 1 m in height, and the frequency | count of dropping until electric leakage occurred was measured.

  Table 5 below shows the results of evaluation of the drop strength.

  As can be seen from Table 5, any metal material can be used as the metal layer of the exterior material, but it is preferable to use a metal material with higher hardness. In addition, it is preferable to use the same material for the inner resin layer of the exterior material and the resin frame because the bonding strength is increased and the strength against dropping is improved. Furthermore, the strength of the resin frame can be improved by mixing glass fibers in the resin frame as in Example 3-12 or providing a metal skeleton on the outer wall surface of the resin frame as in Example 3-16. This is preferable because the strength of the battery pack is improved. Further, as in Example 3-13 and Example 3-14, the strength of the battery pack is improved by configuring the battery pack so as to cover the side surface of the resin frame by bending the end portion of the exterior material. It is preferable because it can be used. In particular, it is preferable to inject a resin material into an exterior material having a bent end and mold the resin frame integrally because the strength is remarkably improved compared to molding the resin frame in a separate process.

  As described above, by using a resin frame with a low moisture permeability to which a moisture absorbent is added and using an exterior material mainly composed of hard metal, a non-aqueous electrolyte secondary battery and a battery pack are manufactured. In addition, it is possible to obtain a battery pack excellent in volume efficiency and drop strength of the battery element.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.

  For example, the numerical values and materials listed in the above-described embodiments are merely examples, and different numerical values and materials may be used as necessary.

  In addition, the configuration according to the present invention is not limited to the secondary battery, and can be used in all batteries that can take a configuration in which a power generation element is accommodated in a resin frame and sealed with an exterior material. .

  For example, the inner resin layer 22 of the exterior material 3 may contain a moisture absorbent.

It is a schematic diagram which shows one structural example of the battery pack 1 by this invention. It is a schematic diagram which shows the structure of the battery element 10 which comprises the battery pack 1 by this invention. It is sectional drawing which shows one structural example of the exterior material by this invention. It is a schematic diagram which shows the other structural example of the battery pack by this invention. It is a schematic diagram which shows the other structural example of the battery pack by this invention. It is a schematic diagram which shows the other structural example of the battery pack by this invention. It is a top view which shows the structural example of the resin frame by this invention. It is a schematic diagram which shows the other structural example of the battery pack by this invention. It is a top view which shows the other structural example of the resin frame by this invention. It is a top view which shows the other structural example of the resin frame by this invention. It is a schematic diagram which shows one structural example of the nonaqueous electrolyte secondary battery by this invention. It is a top view which shows the other structural example of the resin frame by this invention. It is a schematic diagram which shows the other structural example of the battery pack by this invention. It is a schematic diagram which shows one structural example of the soft laminate film by this invention. It is a schematic diagram which shows the other structural example of the battery pack by this invention. It is a schematic diagram which shows the other structural example of the battery element by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery pack 2 ... Nonaqueous electrolyte secondary battery 3, 3a, 3b ... Exterior material 4 ... Resin frame 4a ... Moisture absorption layer 4b ... Resin layer 5 ... Top Cover 6 ... Circuit board 7 ... Connection terminal 8 ... Opening 10 ... Battery element 11 ... Positive electrode 12 ... Negative electrode 13, 13a, 13b ... Separator 14 ... Electrode terminal 14a ... Positive electrode terminal 14b ... Negative electrode terminal 17 ... Laminate film

Claims (30)

A battery element containing a non-aqueous electrolyte;
A resin frame with four continuous sides;
A non-aqueous electrolyte secondary battery having an exterior material formed by laminating a metal layer and a resin layer,
The resin frame has at least one moisture absorption layer,
A non-aqueous electrolyte secondary battery sealed by the battery element being housed in the resin frame and the exterior material being provided so as to cover an opening of the resin frame. A battery element containing a non-aqueous electrolyte;
A resin frame with four continuous sides;
An exterior material formed by laminating a metal layer and a resin layer;
A battery pack having a circuit board,
The resin frame has at least one moisture absorption layer,
The battery element is accommodated in the resin frame, and the nonaqueous electrolyte secondary battery sealed by providing the exterior material so as to cover the opening of the resin frame is electrically connected to the circuit board. Battery pack. The water absorption layer is composed of sodium sulfate, magnesium sulfate, calcium sulfate, copper sulfate, magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, calcium chloride, magnesium chloride, sodium nitrate, calcium hydroxide, magnesium perchlorate, zeolite, Diphosphorus pentoxide, calcium carbonate, or a polyacrylate represented by the general formula (—CH ₂ —CH (COOM) —) _n (wherein M is selected from Na, K, Mg, and Ca). The battery pack according to claim 2, which contains at least one moisture absorbent selected from the group consisting of:   The battery pack according to claim 3, wherein the moisture absorbent is contained in the moisture absorbing layer in an amount of 0.10 wt% to 75.0 wt%.   The battery pack according to claim 3, wherein the moisture absorbent is contained in the moisture absorbing layer in an amount of 5.0 wt% to 75.0 wt%.   The resin frame is made of polyethylene, polypropylene, ethylene vinyl acetate copolymer, ethylene vinyl acetate alcohol copolymer, ethylene / acrylic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, Methacrylic acid copolymer, ethylene / methyl methacrylic acid copolymer, ionomer, polyacrylonitrile, polyvinylidene chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyphenylene ether, polyethylene terephthalate hot melt agent, polyamide hot melt agent The battery pack according to claim 2, comprising at least one resin material selected from the group as a main component.   The battery pack according to claim 2, wherein the resin frame and the resin layer of the exterior material are heat-sealed.   The battery pack according to claim 2, wherein the resin frame and the resin layer of the exterior material have the same kind of molecular structure.   The battery pack according to claim 2, wherein the resin frame is molded integrally with a connection terminal provided so as to communicate from an inner wall portion to an outer wall portion of the resin frame.   The battery pack according to claim 9, wherein the battery element and the circuit board are electrically connected via the connection terminal.   The battery pack according to claim 2, wherein the resin frame is molded integrally with the exterior material.   At least one of an aluminum vapor-deposited film, a carbon vapor-deposited film, a silicon oxide vapor-deposited film, an aluminum oxide vapor-deposited film, a polyvinylidene chloride coating film, and a layered silicate film was formed on the outer wall and / or inner wall of the resin frame. The battery pack according to claim 2.   The battery pack according to claim 2, wherein at least a part of an outer wall portion of the resin frame is covered with the exterior material.   The battery pack according to claim 2, wherein the resin frame contains glass fibers.   The battery pack according to claim 2, wherein the electrode terminal of the battery element is led out through a joint surface of the resin frame and the exterior material, and a portion of the electrode terminal facing the joint surface is covered with a resin material.   The above resin materials include maleic anhydride modified polyethylene, maleic anhydride modified polypropylene, polyethylene to which a titanate coupling agent is added, polypropylene to which a titanate coupling agent is added, ionomer, ethylene / acrylic acid copolymer, ethylene The battery pack according to claim 15, which is at least one resin material selected from the group consisting of a methacrylic acid copolymer and an ethylene vinyl acetate copolymer.   The battery pack according to claim 2, wherein the surface of the electrode terminal derived from the battery element is subjected to primer processing. The exterior material has an inner resin layer on the inner surface of the metal layer,
The inner resin layer is made of polyethylene, polypropylene, ethylene vinyl acetate copolymer, ethylene vinyl acetate alcohol copolymer, ethylene / acrylic acid copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl acrylate copolymer, ethylene・ From methacrylic acid copolymer, ethylene / methyl methacrylic acid copolymer, ionomer, polyacrylonitrile, polyvinylidene chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyphenylene ether, polyethylene terephthalate hot melt agent, polyamide hot melt agent The battery pack according to claim 2, comprising at least one of resin materials selected from the group consisting of as a main component. The exterior material further has an outer resin layer on the outer surface of the metal layer,
The outer resin layer is made of stretched nylon, stretched polyethylene terephthalate, stretched polyethylene naphthalate, stretched polybutylene terephthalate, stretched polybutylene naphthalate, stretched polypropylene, stretched polyethylene. The battery pack according to claim 18, comprising at least one resin material selected from the group as a main component. The metal layer of the exterior material is made of a hard metal,
The battery pack according to claim 2, wherein the hard metal is any one of hard aluminum, stainless steel, titanium, copper, and iron plated with any of tin, zinc, and nickel.   The battery pack according to claim 20, wherein the thickness of the hard metal is 50 µm or more and 100 µm or less.   The battery pack according to claim 20, wherein the hard aluminum is any one of 3003H18, 3004H18, 1N30H18, and 5000 series.   The battery pack according to claim 20, wherein the stainless steel is austenite.   The battery pack according to claim 2, wherein the exterior material is formed by insulating and anchoring the outer surface of the metal layer.   The battery pack according to claim 2, wherein a printed layer is provided on a part or the entire outer surface of the exterior material.   The battery pack according to claim 2, wherein a colored layer is provided on a part of or the entire outer surface of the exterior material, and the colored layer is burned off by a laser and printed. A step of molding a resin frame having four continuous sides made of a resin material containing a moisture absorbent,
Accommodating the battery element in the resin frame;
And a step of sealing the opening of the resin frame so as to be covered with an exterior material formed by laminating a metal layer and a resin layer. An exterior material formed by laminating a metal layer and a resin layer is inserted into an injection mold, and a resin material containing a moisture absorbent is injected into the exterior material to integrally fix a resin frame having four continuous sides. Process,
A step of accommodating a battery element in a recess formed from the exterior material and the resin frame;
And a step of sealing the opening of the recess so as to be covered with the exterior material or another exterior material. A step of molding a resin frame having four continuous sides made of a resin material containing a moisture absorbent,
Accommodating the battery element in the resin frame;
Sealing the opening of the resin frame so as to cover with an exterior material formed by laminating a metal layer and a resin layer;
Electrically connecting the battery element and the circuit board accommodated in the top cover;
A method for producing a battery pack, comprising the step of joining the exterior material and the top cover. An exterior material formed by laminating a metal layer and a resin layer is inserted into an injection mold, and a resin material containing a moisture absorbent is injected into the exterior material to integrally fix a resin frame having four continuous sides. Process,
A step of accommodating a battery element in a recess formed from the exterior material and the resin frame;
Sealing the opening of the recess so as to cover the exterior material or other exterior material;
Electrically connecting the battery element and the circuit board accommodated in the top cover;
A method for producing a battery pack, comprising the step of joining the exterior material and the top cover.

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