JP5504554B2 - Battery pack manufacturing method and battery pack - Google Patents

Description

    The present invention relates to a method of manufacturing a battery pack including, for example, a non-aqueous electrolyte secondary battery. More specifically, the present invention relates to a battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode through a separator is wrapped with a laminate film and its protection. The present invention relates to a method of manufacturing a battery pack in which a circuit board is integrated.

  In recent years, a large number of portable electronic devices such as camera-integrated video tape recorders, mobile phones, and portable computers have appeared, and their size and weight have been reduced. With the reduction in size and weight of such electronic devices, battery packs used as portable power sources are also required to have high energy and be reduced in size and weight. As a battery used for such a battery pack, there is a lithium ion secondary battery having a high capacity.

A lithium ion secondary battery includes a battery element having a positive electrode and a negative electrode that can be doped and dedoped with lithium ions. The battery element is enclosed in a metal can or a metal laminate film and electrically connected to the battery element. The circuit board is controlled. In addition, some conventional lithium ion secondary batteries are housed together with a circuit board in a housing case that is divided into two parts vertically (see, for example, Patent Documents 1-3).
Japanese Patent No. 3556875 Japanese Patent No. 3614767 Japanese Patent No. 3643792

  By the way, in the conventional lithium ion secondary battery as described above, when a metal can is used to enclose the battery element, high dimensional accuracy is easily secured, but the thickness and weight are slightly increased. On the other hand, using a metal laminate film to enclose a battery element is thinner and lighter than a metal can, but it is difficult to increase dimensional accuracy due to large variations in the dimensions of the battery element, as well as mechanical strength. Has the disadvantage of being low.

  In addition, in a conventional battery pack in which a lithium ion secondary battery and a circuit board are stored in a storage case, the storage case is sufficient to protect the lithium ion secondary battery and the circuit board from external shocks. In addition, when the storage case divided into upper and lower parts is joined by double-sided tape or ultrasonic welding, it is necessary to secure a sufficient thickness in the storage case so as to be able to cope with them. As a result, the thickness and weight of the entire battery pack increase, which is not preferable as a portable power source.

  The present invention has been made paying attention to the above-described conventional problems, and an object of the present invention is to provide a battery pack that achieves both high dimensional accuracy and mechanical strength, as well as reduction in size and weight.

  As a result of intensive studies to achieve the above object, the present inventors have found that a battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode through a separator is wrapped with a laminate film, a protective circuit board for the battery, Can be achieved by filling the battery and the protective circuit board integrally with the exterior material by filling the exterior space with the exterior material in the molding space of the mold. As a result, the present invention has been completed.

  In filling the exterior material, particularly the exterior material having viscosity, into the molding space of the mold, it is usually necessary to fill the exterior material at a high pressure for the purpose of preventing the formation of a gap in the molding space. In this case, in order to prevent the battery and the protection circuit board from moving from a predetermined position in the molding space by the exterior material filled with high pressure, for example, when a measure for providing a positioning projection on the molding die is taken. However, there have been obstacles such as a recess for positioning formed at the time of curing of the exterior material impairs the design or becomes difficult to use by the user.

Therefore, in the battery pack of the present invention, for example, the pair of surfaces is at least the maximum surface of the six faces of the tabular battery provided space Sa for a battery position holding, molding space of the battery and the protection circuit board The spacers can be held in a predetermined position in the interior, and the exterior material can flow into every corner of the molding space of the mold while covering the maximum surface and maintaining the space for filling the exterior material. placement, and the children of the scan pacer eventually be integrated with the exterior material are Unishi'll be remaining in the battery pack.

That is, the battery pack manufacturing method of the present invention includes a rectangular plate-shaped battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode with a separator interposed between them, and a protection circuit board for the battery. Through spacers arranged on a pair of surfaces that are the largest of the six planes, set at a predetermined position in the molding space of the mold,
By filling and curing the exterior material in the molding space of the mold, the battery and the protective circuit board are integrally covered with the exterior material,
A method for producing a battery pack, wherein the spacer includes at least one resin material selected from polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene, and polyethylene.

The battery pack of the present invention comprises a rectangular plate-shaped battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode with a separator interposed between them and a protective circuit board for the battery are provided on six planes of the battery. It is set at a predetermined position in the molding space of the molding die through spacers arranged on a pair of surfaces which are the largest surfaces of them,
The battery and the protective circuit board are integrally covered with the exterior material filled and cured in the molding space of the mold,
In the battery pack, the spacer includes any one of at least one resin material selected from polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene, and polyethylene.

In the present invention, when filling the outer package to the mold of the molding space, it is possible to position accurately a predetermined position more battery and the protection circuit board to space Sa, for example, six faces of the tabular battery In all, a strong exterior material layer can be formed with high accuracy almost as designed, and in addition, by increasing or decreasing the amount of exterior material injection, the battery element can be made of a laminate film or a film with a two-layer structure containing at least polyolefin. variations in packaged manufacturing inevitable size of batteries that can be absorbed by the six planes entirely, that do is possible to supply very high dimensional accuracy battery pack stably.

  In the present invention, since the battery and the protection circuit board are integrally covered with the exterior material, a pair of surfaces which are conventionally required, for example, the maximum surfaces of the six flat surfaces of a flat battery Since it is not necessary to provide a hard cover for covering, it is possible to realize a reduction in size and weight in addition to an improvement in mechanical strength.

  According to the present invention, since it is configured as described above, there is a very excellent effect that it is possible to provide a battery pack that has both high dimensional accuracy and mechanical strength, and that also realizes a reduction in size and weight. Brought about.

  Hereinafter, the battery pack of the present invention will be described in detail. In the present specification, “%” for concentration, content, filling amount, and the like represents a mass percentage unless otherwise specified.

  As described above, the battery pack of the present invention includes a polymer-type nonaqueous electrolyte secondary battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode via a separator is wrapped with a laminate film, and a protection circuit for this battery The substrate is integrally covered with an exterior material, and the exterior material can be a composite material including a resin and a metal oxide filler.

  Here, as the resin constituting the exterior material, a resin having a compatibility, compatibility or reactivity with the metal oxide filler, and having a high dimensional accuracy and strength as a constituent resin is preferable. For example, an acrylic resin or an epoxy resin can be suitably used as the shape maintaining polymer layer (polymer film). In addition, as a shape maintenance polymer, the adhesiveness with a metal laminate film is favorable, and the thing excellent in dimensional stability and a moldability is preferable.

  On the other hand, as the metal oxide filler, silicon (Si), aluminum (Al), titanium (Ti), zirconium (Zr), zinc (Zn), magnesium (Mg) oxide, or any mixture of these oxides Can be mentioned. Such a metal oxide filler functions to improve the hardness of the exterior material and is disposed in contact with the shape maintaining polymer layer. For example, the metal oxide filler is mixed into the shape maintaining polymer layer. In this case, it is preferable that the shape maintaining polymer layer is uniformly dispersed throughout the shape maintaining polymer layer.

  The mixing amount of the metal oxide filler can be appropriately changed according to the polymer type of the shape maintaining polymer layer, etc., but when the mixing amount with respect to the mass of the shape maintaining polymer layer is less than 3%, this exterior material On the other hand, when the mixing amount exceeds 60%, problems due to formability during production and brittleness of the ceramic may occur. It is preferable that the mixing amount of the metal oxide filler with respect to the mass is about 3 to 60%.

  In addition, if the average particle size of the metal oxide filler is reduced, the hardness is increased, but the filling property at the time of molding may be affected, which may cause a problem in productivity. If it is increased, it may be difficult to obtain the desired strength, and sufficient dimensional accuracy as a battery pack may not be obtained. Therefore, the average particle size of the metal oxide filler is preferably 0.5 to 40 μm. 2 to 20 μm is more preferable.

  Furthermore, various shapes such as a spherical shape, a scale shape, a plate shape, and a needle shape can be adopted as the shape of the metal oxide filler. Although not particularly limited, a spherical shape is preferable because it is easy to produce and can be obtained at a low cost with a uniform average particle diameter, and a needle-like shape having a high aspect ratio is preferable because it can easily increase the strength as a filler. . Moreover, a scale-like thing is preferable since filling property can be improved when the filler content is increased. In addition, it is possible to mix and use fillers having different average particle diameters or to mix and use fillers having different shapes depending on applications and materials.

  As described above, the exterior material in the battery pack of the present invention desirably has a shape maintaining polymer layer and a predetermined metal oxide filler, but can contain various additives other than this, for example, In the shape maintaining polymer layer, an ultraviolet absorber, a light stabilizer, a curing agent, or any mixture thereof can be added to coexist with the metal oxide filler.

  The exterior material has a small thickness, for example, the shape maintaining polymer layer has a thickness of 1000 μm or less. When the thickness of the shape-maintaining polymer layer exceeds 1000 μm, even if the battery pack is manufactured using this exterior material, it may be difficult to exhibit merit in terms of volume energy density. More preferably, the thickness of the shape-maintaining polymer layer is 300 μm or less, and the thinner it is, as long as the required mechanical strength and impact resistance can be satisfied.

  Thus, the above-described exterior material is thinner than the conventional one and can realize a high-strength battery pack, and can also realize a reduction in size and weight of the battery pack. In addition, by using any one of an ultraviolet absorber, a light stabilizer and a curing agent together with the metal oxide filler as described above, and using any one of urethane resin, acrylic resin and epoxy resin, the metal Since it is thinner than the plate and can be processed with high productivity, not only the energy density of the resulting battery is improved, but also the battery pack can be easily formed, the dimensional accuracy is increased, and the yield is improved. In addition, the degree of freedom in designing the size, shape and strength according to a wide variety of applications will be expanded.

  Next, the battery pack of the present invention will be described in detail with reference to the drawings.

  FIGS. 1-7 has shown one Embodiment of the battery pack of this invention, and as shown in FIG. 5, this battery pack is the battery 20 produced by coat | covering the battery element 10 with the metal laminate film 17. FIG. It has. In this battery 20, the battery element 10 is accommodated in a recess 17 a (vacant space 17 a) formed in the laminate film 17, and its peripheral part is sealed. In this case, the void 17 a of the laminate film 17 is sealed. Is a rectangular plate-like space corresponding to the shape of the battery element 10 having a rectangular plate shape.

  As shown in FIG. 6, the battery element 10 includes a belt-like positive electrode 11, a separator 13 a, a belt-like negative electrode 12 disposed so as to face the positive electrode 11, and a separator 13 b in this order. The gel electrolyte 14 is applied to both surfaces of the positive electrode 11 and the negative electrode 12.

  From this battery element 10, a positive electrode terminal 15a connected to the positive electrode 11 and a negative electrode terminal 15b connected to the negative electrode 12 are derived (hereinafter referred to as an electrode terminal 15 when a specific terminal is not designated), and the positive electrode terminal 15a. The negative electrode terminal 15b has sealants 16a and 16b (hereinafter referred to as specific sealants), which are resin pieces such as polypropylene (PPa) modified with maleic anhydride, in order to improve the adhesion to the laminate film 17 to be packaged later. If not specified, it is appropriately referred to as sealant 16).

Hereinafter, the constituent elements of the above-described battery (before packing with the exterior material) will be described in detail.
[Positive electrode]
The positive electrode is formed by forming a positive electrode active material layer containing a positive electrode active material on both sides of a positive electrode current collector. The positive electrode current collector is composed of a metal foil such as an aluminum (Al) foil, while the positive electrode active material layer is composed of, for example, a positive electrode active material, a conductive agent, and a binder. . Here, the positive electrode active material, the conductive agent, the binder, and the solvent only have to 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, when a lithium ion battery is configured, the following formula (1) is mainly used.
LiXMO2 (1)
(Wherein M represents at least one transition metal, and X varies depending on the charge / discharge state of the battery, but is usually 0.05 to 1.10.) Can be used. Note that cobalt (Co), nickel (Ni), manganese (Mn), or the like can be used as the transition metal (M) constituting the lithium composite oxide.

Examples of the lithium composite oxides, _{specifically, LiCoO 2, LiNiO 2, LiMn} 2 O 4 and LiNi _y Co ₁ - is _{y O 2 (0 <y <} 1) or the like. In addition, a solid solution in which a part of the transition metal element is substituted with another element can be used, and examples thereof include LiNi _0.5 Co _0.5 O ₂ and LiNi _0.8 Co _0.2 O _2. Can do. These lithium composite oxides can generate a high voltage and have an excellent energy density. Furthermore, _{TiS 2,} MoS 2, may be used NbSe no lithium metal sulfides such as ₂ and _V 2 _{O 5} or the oxide as a cathode active material. These positive electrode active materials may be used alone or in admixture of a plurality of types.

  In addition, as the conductive agent, for example, a carbon material such as carbon black or graphite can be used. Furthermore, as the binder, for example, polyvinylidene fluoride, polytetrafluoroethylene, polyvinylidene fluoride, or the like can be used. Moreover, as a solvent, N-methylpyrrolidone etc. can be used, for example.

  The above-described positive electrode active material, binder and conductive agent are uniformly mixed to form a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent to form a slurry. Next, this slurry is uniformly applied on the positive electrode current collector by a doctor blade method or the like, and then dried at a high temperature to evaporate the solvent and press to form a positive electrode active material layer.

  The positive electrode 11 has a positive electrode terminal 15a connected to one end of the positive electrode current collector by spot welding or ultrasonic welding. The positive electrode terminal 15a is preferably a metal foil or a mesh-like one, but there is no problem even if it is not a metal as long as it is electrochemically and chemically stable and can be energized. Examples of the material of the positive electrode terminal 15a include aluminum.

[Negative electrode]
The negative electrode is formed by forming a negative electrode active material layer containing a negative electrode active material on both surfaces of a negative electrode current collector. The negative electrode current collector is composed of a metal foil such as a copper (Cu) foil, a nickel foil, or a stainless steel foil.

  The negative electrode active material layer includes, for example, a negative electrode active material, a conductive agent as necessary, and a binder. In addition, about a negative electrode active material, a electrically conductive agent, a binder, and a solvent, the mixing ratio is not ask | required similarly to a positive electrode active material.

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-based material and a carbon-based material can be used. Specific examples of carbon materials 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, and activated carbon can be used. Furthermore, as a material that can be doped / undoped with lithium, polymers such as polyacetylene and polypyrrole, and oxides such as SnO ₂ can be used.

  As materials capable of alloying lithium, various kinds of metals can be used, but tin (Sn), cobalt (Co), indium (In), aluminum, silicon (Si), and alloys thereof. Is often used. When metal lithium is used, it is not always necessary to use powder as a coating film with a binder, and a rolled lithium metal foil may be pressure-bonded to a current collector.

  As the binder, for example, polyvinylidene fluoride, styrene butadiene rubber, or the like can be used. Moreover, as a solvent, N-methylpyrrolidone, methyl ethyl ketone, etc. can be used, for example.

  The above-described negative electrode active material, binder, and conductive agent are uniformly mixed to form a negative electrode mixture, which is dispersed in a solvent to form a slurry. Subsequently, after apply | coating uniformly on a negative electrode electrical power collector by the method similar to a positive electrode, it is made to dry at high temperature, a solvent is scattered, and a negative electrode active material layer is formed by pressing.

  Similarly to the positive electrode 11, the negative electrode 12 also has a negative electrode terminal 15b connected to one end of the current collector by spot welding or ultrasonic welding, and this negative electrode terminal 15b is electrochemically and chemically stable. There is no problem even if it is not metal if it can be energized. Examples of the material of the negative electrode terminal 15b include copper and nickel.

  In addition, as described above, when the battery element 10 has a rectangular plate shape, the positive electrode terminal 15a and the negative electrode terminal 15b are preferably led out from one side (usually one of the short sides) in the same direction. As long as no short circuit occurs and the battery performance is not a problem, there is no problem even if it is derived from any direction. Moreover, as long as the electrical connection is taken for the connection location of positive electrode terminal 15a and 15b, the attachment location and the attachment method are not limited to said example.

[Electrolyte]
As the electrolytic solution, an electrolyte salt and a non-aqueous solvent that are generally used in lithium ion batteries 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 and ethylpropyl carbonate, or hydrogen of these carbonic acid esters to halogen. There are substituted solvents and the like. One of these solvents may be used alone, or a plurality of these solvents may be mixed and used in a predetermined composition.

Moreover, as lithium salt which is an example of electrolyte salt, it is possible to use the material used for normal battery electrolyte solution. 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 desirable from the viewpoint of oxidation stability. These lithium salts may be used alone or in combination of two or more. The concentration for dissolving the lithium salt is not a problem as long as it can be dissolved in the non-aqueous solvent, but the lithium ion concentration is in the range of 0.4 mol / kg to 2.0 mol / kg with respect to the non-aqueous solvent. It is preferable that

  In the case of using a gel electrolyte, the above-described electrolytic solution is gelled with a matrix polymer. The matrix polymer is not particularly limited as long as it is compatible with a non-aqueous electrolyte obtained by dissolving the electrolyte salt in the non-aqueous solvent and can be gelled. Examples of such a matrix polymer include a polymer containing polyvinylidene fluoride, polyethylene oxide, polypropylene oxide, polyacrylonitrile, and polymethacrylonitrile in repeating units. Such a polymer may be used individually by 1 type, and 2 or more types may be mixed and used for it.

Among them, particularly preferable as the matrix polymer is polyvinylidene fluoride or a copolymer in which hexafluoropropylene is introduced into polyvinylidene fluoride at a ratio of 7.5% or less. Such polymers usually 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 0.1 × 10 ⁵ (210,000-310,000) and intrinsic viscosity in the range of 1.7-2.1 dl / g.

[Separator]
The separator is composed 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. The porous film may be laminated. Among these, polyethylene and polypropylene porous films are the 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.

[Production of battery]
The gel electrolyte solution prepared as described above is uniformly applied to the positive electrode 11 and the negative electrode 12 and impregnated in the positive electrode active material layer and the negative electrode active material layer, and then stored at room temperature or subjected to a drying process. A state electrolyte layer 14 is formed.

  Next, using the positive electrode 11 and the negative electrode 12 on which the gel electrolyte layer 14 is formed, the positive electrode 11, the separator 13 a, the negative electrode 12, and the separator 13 b are stacked in this order and then wound to form the battery element 10. 10 is accommodated in a recess (vacant space) 17a of the laminate film 17 and packaged to obtain a gel-like nonaqueous electrolyte secondary battery.

  As the laminate film 17, a conventionally known metal laminate film such as an aluminum laminate film can be used. As such an aluminum laminate film, a film suitable for drawing and suitable for forming the recess 17a for accommodating the battery element 10 is preferable.

  In general, an aluminum laminate film has a laminated structure in which an adhesive layer and a surface protective layer are disposed on both sides of an aluminum layer, and a polypropylene layer (PP as an adhesive layer) in order from the inside, that is, the surface side of the battery element 10. Layer), an aluminum layer as a metal layer, and a nylon layer or a polyethylene terephthalate layer (PET layer) as a surface protective layer.

  In this embodiment, as shown in FIGS. 5 and 6, the battery element 10 is packaged with the laminate film 17 as described above, and the periphery of the battery element 10 is welded and sealed to form the battery 20. Further, as described above, after the battery element 10 is accommodated and sealed in the laminate film 17, as shown in FIGS. 7A and 7B, the concave portion 17a accommodating the battery element 10 is formed. The portions 17b on both sides (hereinafter referred to as side sealing portions as appropriate) 17b are bent toward the concave portion 17a.

  The bending angle θ is preferably in the range of 80 ° to 100 °. If the angle is less than 80 °, the side sealing portions 17b provided on both sides of the concave portion 17a are excessively opened, and the width of the battery 20 is widened, making it difficult to reduce the size of the battery 20 and improve the battery capacity. The upper limit of 100 ° is a value defined by the shape of the recess 17a. When the flat battery element 10 is accommodated, the limit value of the bending angle is about 100 °. In addition, the width | variety of the heat welding in the side sealing part 17b becomes like this. Preferably it is 0.5-2.5 mm, More preferably, it is 1.5-2.5 mm.

  The folded width D of the side sealing portion 17b is preferably set to a dimension equal to or smaller than the height h of the concave portion 17a or the thickness of the battery element 10 in order to reduce the size of the battery 20 and improve the battery capacity. Further, in order to reduce the size of the nonaqueous electrolyte secondary battery 20 and improve the battery capacity, the number of turns is preferably set to one.

  Next, an embodiment of the battery pack manufacturing method of the present invention will be described.

  In the battery pack manufacturing method in this embodiment, the non-aqueous electrolyte secondary battery 20 produced as described above is formed into a cavity of a molding die (molding) together with a protective circuit board and a spacer capable of controlling the voltage and current of the battery. Space), the battery and the protective circuit board are set at predetermined positions in the cavity by the spacer, and then the exterior material containing the shape maintaining polymer and filler is filled in the cavity and cured, A battery pack equipped with an exterior material is obtained.

  As described above, the spacer is provided on a pair of surfaces which are at least the largest surface among the six flat surfaces of the battery having a rectangular plate shape, and the lithium ion secondary battery and the protection circuit board are disposed in the molding space. It is arranged to cover the maximum surface and maintain the filling space of the exterior material so that the exterior material flows into every corner of the molding space of the mold while being able to be held in the center with high accuracy. Finally, it is integrated with the exterior material and remains in the battery pack, which can greatly contribute to the formation of a uniform shape maintaining polymer layer.

  In addition, the spacer described above is preferably not thermally deformed when integrated with the exterior material and thermally cured, and is preferably transparent when cured with ultraviolet rays. It should be noted that any material such as metal, glass or resin may be used as long as the accuracy of the thickness dimension is maintained without being deformed when thermosetting. Although not particularly limited, materials such as acrylic resin, epoxy resin, polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene, polyethylene, etc. with high dimensional accuracy, and metals such as aluminum and stainless steel are used as materials. Alternatively, a resin material in which a metal material such as aluminum is insert-molded can be used.

  Furthermore, the shape of the spacer 35 described above is not particularly limited, but can be the columnar spacer 35 shown in FIG. 4, the frustoconical spacer 35 shown in FIG. 8, or the shape shown in FIG. 9. A prism-shaped spacer 35, a rectangular parallelepiped spacer 35 shown in FIG. 10, a truncated pyramid-shaped spacer 35 shown in FIG. 11, a mesh-like spacer 35 shown in FIG. 12, and a cross-shaped spacer 35 shown in FIG. It can be.

  In the above embodiment, the molding die to be used includes the battery 20 packed with the aluminum laminate film 17, the protection circuit board, the spacer described above, and a cushioning material (described later) used as necessary. Although it is not particularly limited as long as it can be arranged in the cavity, it usually has two or more gates for introducing the melt molding material into the cavity. Therefore, in the obtained battery pack, an excess of the molding material corresponding to the gate is cured and remains in any part of the exterior material. In the present invention, the excess molding material is trimmed. However, some resin injection marks remain.

  The protection circuit is usually disposed above the positive terminal 15a and the negative terminal 15b (see FIG. 5). Further, when the above-described cushioning material has a rectangular plate shape like the battery 20 (when the formed battery exterior material has a rectangular plate shape), the side portions in the lead-out direction of the terminals 15a and 15b or the sides facing the side portions. Placed on either side or both sides. Specifically, in FIG. 5, the battery 20 having a rectangular plate shape is arranged on one short side or both short sides. The protective circuit board and the buffer material arranged in this way are integrated with the battery 20 by the exterior material.

  In addition, since the said buffer material has a function which improves the impact resistance of the battery pack obtained while protecting a battery and a circuit board, as a material used for this buffer material, it has impact resistance and dimensions. Use high-precision polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene, polyethylene, or other metals, or metals such as aluminum or stainless steel, or resin-molded metal materials such as aluminum. Is preferred.

  In the present invention, unlike the conventional case, all dimensional variations can be absorbed by the shape maintaining polymer layer, and therefore various rubber-like plastics can be used. Specifically, natural rubber, vulcanized synthetic rubber, such as polybutadiene, butadiene-acrylonitrile, styrene-butadiene, chloroprene, etc., ebonite, urethane rubber, silicon rubber can be used.

  Next, the point of manufacturing the battery pack of the present embodiment will be described. As shown in FIG. 2, first, the side sealing portion 17b along the side surface of the battery 20 is shown in the drawing in order to increase the rigidity and the resin biting property. The state shown in FIG. 3A is formed by bending along the broken line.

  Next, the protective circuit board 32 and the buffer material 34 are disposed on the top side of the battery 20, and the buffer material 33 is disposed on the bottom side, and the pair of surfaces 17 c that are the largest surfaces of the six planes of the battery 20 are provided. In the state where the cylindrical spacers 35 are arranged, as shown by phantom lines in FIGS. 3B and 3C, after being placed in the cavity Ca of the molding die C, the above shape maintaining polymer and filler Is injected into the cavity Ca of the molding die C.

  At this time, since the spacer 35 is in contact with the molding die C, the battery 20 and the protection circuit board 32 are accurately held at predetermined positions in the cavity Ca, and in addition, the maximum surface of the battery 20 Since the spacer 35 is disposed so as to cover the space 17c and maintain the filling space of the exterior member 18, the exterior member 18 flows into every corner in the cavity Ca.

  Then, when the outer packaging material 18 containing the shape maintaining polymer and the filler is cured in the cavity Ca, the battery pack 30 of the present embodiment in which the aluminum laminate film 17 is covered with the outer packaging material 18 as shown in FIG. At this time, the spacer 35 is integrated with the cured outer packaging 18 and remains in the battery pack 30.

  Thus, according to the present invention, it is possible to obtain a battery pack that has both high dimensional accuracy and mechanical strength as described above, and that is reduced in size and weight. In addition, although this battery pack 30 is normally provided with the connection terminal connected with an object apparatus, the description was abbreviate | omitted above.

  Moreover, although the above-mentioned embodiment demonstrated using the non-aqueous electrolyte secondary battery 20 using a gel electrolyte, this invention is applicable also to the laminate film exterior battery pack using electrolyte solution. In this case, in the above-described embodiment, the step of applying the gel electrolyte to the positive electrode and the negative electrode surface is omitted, and the step of injecting the electrolytic solution in the middle of the laminate film welding step is provided. More specifically, after welding and sealing three sides around the battery element 10 having a rectangular plate shape, an electrolyte is injected from the opening on the other side, and then this one side is welded. What is necessary is just to seal. Thereby, the whole shape of a sealing part becomes a rectangular frame shape.

  Furthermore, in the above-described embodiment, the case where the battery element 10 is formed by winding the positive electrode 11 and the negative electrode 12 via the separators 13a and 13b is shown. However, as shown in FIG. Needless to say, the present invention can also be applied to a battery pack having battery elements 10 that are alternately stacked via 13.

  In the embodiment described above, the nonaqueous electrolyte secondary battery 20 is housed in a cavity (molding space) of a molding die together with a protective circuit board and a spacer capable of controlling the voltage and current of the battery, and the battery is separated by the spacer. The protective circuit board is set at a predetermined position in the cavity, and then the exterior material containing the shape maintaining polymer and filler is filled in the cavity and cured, thereby obtaining a battery pack having the exterior material attached thereto. However, as another embodiment, the protrusion formed or pasted on the molding die is used as a positioning member, and the protrusion is arranged so as to spread the exterior material over the entire space around the battery and the protection circuit board. After the battery and the protection circuit board are set at predetermined positions in the cavity by the protrusion, the exterior containing the shape maintaining polymer and the filler The may be cured by filling in the cavity.

As a reference example of the battery pack manufacturing method , as shown in FIG. 15B, a protective circuit board 32 and a buffer are provided on the top side of the battery 20 in a cavity Ca of a molding die C having a protrusion as a positioning member. After the material 34 is disposed and the cushioning material 33 is disposed on the bottom side, and the protrusions 35A are placed in contact with the pair of surfaces 17c, which is the largest surface among the six flat surfaces of the battery 20, The packaging material 18 containing the shape maintaining polymer and filler may be injected into the cavity Ca of the molding die C.

  At this time, since the protrusion 35A is in contact with the molding die C, the battery 20 and the protection circuit board 32 are accurately held in the predetermined position in the cavity Ca, and in addition, the maximum surface of the battery 20 Since the projections 35A are arranged so as to cover the space 17c and maintain the filling space of the exterior material 18, the exterior material 18 flows into every corner in the cavity Ca.

  Then, when the packaging material 18 containing the shape maintaining polymer and the filler is cured in the cavity Ca, the battery pack of the present embodiment in which the aluminum laminate film 17 is covered with the packaging material 18 as shown in FIG. In this case, the positioning mark 35B due to the projection 35A remains as a recess in the hardened exterior material 18. At this time, as shown in FIG. 16, the positioning marks 35 </ b> B remaining on the exterior material 18 can function as information display portions or patterns such as characters, so that the professional design is not impaired.

  The shape of the protrusion 35A described above is not particularly limited, but can be a cylindrical protrusion (see FIG. 4), a truncated cone-shaped protrusion (see FIG. 8), a prismatic protrusion (see FIG. 9), a rectangular parallelepiped projection (see FIG. 10), a truncated pyramid shaped projection (see FIG. 11), a net-like projection (see FIG. 12), and a cross-shaped projection (see FIG. 13). be able to.

EXAMPLES Hereinafter, although an Example , a reference example, and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

(Examples 1-9)
First, a battery 20 having a laminate film 17 in which an adhesive is applied to the inner surface side of an aluminum vapor-deposited PET film is prepared, and the battery 20 is connected to a protective circuit board 32 capable of controlling its voltage and current, and a cushioning material. 33, 34 and the spacer 35 are inserted into the cavity Ca of the mold C, and the battery 20 is fixed at a predetermined position in the cavity Ca by the spacer 35. When a resin containing a metal oxide filler is injected from a 5 mm resin injection hole and filled into the cavity Ca, when excess resin comes out from the resin discharge holes located at three positions below the mold C, it is left at room temperature. The layer of the outer packaging 18 is formed by allowing the resin to cure by standing at a temperature shown in Table 1 in a thermostatic chamber or by irradiating ultraviolet light having a wavelength of 365 nm using a transparent mold. Form, by cutting the extra ramified resin remaining in the resin injection hole and the discharge hole after curing of the resin containing a metal oxide filler, and a battery pack 30 of each example.

  That is, by arranging the spacers 35 of various shapes on the pair of surfaces 17c, which is at least the largest surface of the six planes of the battery 20, the battery 20 is accurately positioned in the center of the cavity Ca, and in this state, By arranging the resin containing the metal oxide filler on the six planes of the battery 20, the battery pack 30 of each example with no time loss in the process was obtained.

( Reference Examples 1-15)
A battery 20 having a laminate film 17 in which an adhesive is applied to the inner surface side of an aluminum vapor-deposited PET film is prepared, and the battery 20 is connected to a protective circuit board 32 capable of controlling its voltage and current, and a buffer material 33, 34 is inserted into the cavity Ca of the molding die C having the projection 35A, and the battery 20 is fixed at a predetermined position in the cavity Ca by the projection 35A. When a resin containing a metal oxide filler is injected from the resin injection hole and filled in the cavity Ca, and when excess resin comes out from the resin discharge holes located at three positions below the mold C, the resin is left at room temperature and kept at a constant temperature. The layer of the outer packaging 18 is formed by allowing the resin to cure by being left standing in the tank at the temperature shown in Table 2 or by irradiating ultraviolet light having a wavelength of 365 nm using a transparent mold. Extra branched resin remaining in the resin injection hole and the discharge hole after curing of the resin containing the metal oxide filler is cut may be a battery pack 30 of each example.

  That is, by bringing the projections 35A of various shapes into contact with the pair of surfaces 17c, which is at least the largest surface among the six flat surfaces of the battery 20, the battery 20 is accurately positioned at the center in the cavity Ca. By arranging the resin containing various metal oxide fillers on the six planes of the battery 20, the battery pack 30 of each example with no time loss in the process was obtained.

(Comparative Example 1)
As Comparative Example 1, a battery pack formed by molding in a molding die C without projections 35A without a spacer 35 was produced, that is, molding was performed without positioning in the cavity Ca of the molding die C. A battery pack was produced. Each specification of the battery pack 30 of Examples 1-9 and Reference Example 1 is shown in Table 1, and each specification of the battery pack 30 of Reference Examples 2-15 and the specification of the battery pack 30 of Comparative Example 1 are shown in Table 2. .

(Performance evaluation)
First, at a temperature of 23 ° C., 1C constant current and constant voltage charging performed for 15 hours with an upper limit of 4.2 V and 1 C constant current discharging up to a final voltage of 2.5 V are repeatedly performed. Table 1 shows the rated energy density obtained from the discharge capacity.
Rated energy density [Wh / l] = (average discharge voltage [V] × rated capacity [Ah]) / battery volume [l]
In addition, 1C shows the electric current value which can discharge | release the theoretical capacity | capacitance of a battery in 1 hour.

  Further, in order to observe the variation in the pack strength of the battery pack 30 in each example, ten battery packs 30 are produced for each example, and all the battery packs 30 are placed on a concrete floor from a height of 2 m. It was allowed to fall freely. At this time, the drop test is performed ten times on one battery pack 30 so that all six planes of one battery pack 30 are in contact with the floor. Those having an abnormality in appearance such as cracking or part removal were determined as defective products, and the obtained determination results are shown in Tables 1 and 2 together.

Further, in the case of a thermosetting resin, the molding die C is filled with one of a urethane resin, an acrylic resin, and an epoxy resin, which is an exterior material 18 containing a metal oxide such as silicon or aluminum, The time required for molding and curing at the curing temperature was defined as the curing time. On the other hand, in the case of an ultraviolet curable resin, a transparent mold is filled with one of a urethane resin, an acrylic resin, and an epoxy resin, which is an exterior material 18 containing a metal oxide such as silicon or aluminum, and ultraviolet irradiation is performed. The time required for molding and curing by irradiating ultraviolet light having a wavelength of 365 nm with an irradiation intensity of 200 mW / cm ² by the apparatus was set as the curing time, and the obtained curing time is also shown in Table 1.

  With the battery 20 having the laminate film 17 coated with an adhesive on the inner surface side of the aluminum vapor-deposited PET film and the protective circuit board 32 being connected, the battery 20 is inserted into the cavity Ca of the mold C together with the cushioning materials 33 and 34 and the spacer 35. Each of the battery packs 30 of Examples 1 to 9 in which the resin containing the metal oxide filler is filled into the cavity Ca and cured while positioning in the cavity Ca of the battery 20 by the spacer 35 is all of the present invention. From the determination result of the drop test shown in Table 1, the battery packs 30 of Examples 1 to 9 are more stable without increasing the time of the production process than the battery pack 30 of Comparative Example 1. It can be seen that it has excellent strength characteristics with the quality obtained.

Further, the battery 20 and the protection circuit board 32 are connected to the cavity Ca of the molding die C having the protrusion 35A, and inserted together with the cushioning materials 33 and 34, and the positioning of the battery 20 in the cavity Ca is performed by the protrusion 35A. Each of the battery packs 30 of Reference Examples 2 to 15 in which the cavity Ca was filled with a resin containing a metal oxide filler while being cured was included in the scope of the present invention, and the drop test determination shown in Table 2 was performed. From the results, it can be seen that each battery pack 30 of Reference Examples 2 to 15 has excellent strength characteristics with stable quality without increasing the time of the production process as compared with the battery pack 30 of Comparative Example 1. I understand.

Above, some preferred embodiments forms state of the present invention has been described by the real施例and reference examples, the present invention is not limited to such embodiments and examples, range variously without departing from the gist of the present invention Can be modified. For example, the battery pack of the present invention can be applied not only to the battery and battery element shown in FIG. 1 and the like, but also to various gel-like or polymer-type non-aqueous electrolyte secondary batteries, and only a wound battery element. In addition, the present invention can be applied to a stacked battery element.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory plan view (A), a longitudinal sectional explanatory view (B), and a horizontal sectional explanatory view (C) showing an embodiment of a battery pack of the present invention. FIG. 2 is an explanatory plan view of the battery showing a state before the side sealing portion of the battery of the battery pack in FIG. 1 is bent. It is plane | planar explanatory drawing (A), longitudinal cross-section explanatory drawing (B), and cross-sectional explanatory drawing (C) of the battery which show the point which coat | covers the battery in FIG. 2 with exterior material, and produces a battery pack. FIG. 2 is a perspective explanatory view of a spacer integrated with an exterior material of the battery pack in FIG. 1. It is a disassembled perspective explanatory view which shows the battery before coat | covering with the exterior material of the battery pack in FIG. It is an isometric view explanatory drawing which shows the battery element packaged and accommodated in a laminate film. It is end surface explanatory drawing (A) and (B) which show the point which bends the side sealing part of the battery shown in FIG. It is the arrangement | positioning condition explanatory drawing (A) with respect to the battery which shows the other structural example of the spacer integrated with the exterior material of the battery pack of this invention, and a perspective explanatory drawing (B). It is arrangement | positioning condition explanatory drawing (A) with respect to the battery which shows the further another structural example of the spacer integrated with the exterior | packing material of the battery pack of this invention, and a perspective explanatory drawing (B). It is arrangement | positioning condition explanatory drawing (A) with respect to the battery which shows the further another structural example of the spacer integrated with the exterior | packing material of the battery pack of this invention, and a perspective explanatory drawing (B). FIG. 12 is a perspective explanatory view showing still another configuration example of the spacer integrated with the exterior material of the battery pack of the present invention. FIG. 12 is a perspective explanatory view showing still another configuration example of the spacer integrated with the exterior material of the battery pack of the present invention. FIG. 12 is a perspective explanatory view showing still another configuration example of the spacer integrated with the exterior material of the battery pack of the present invention. It is a perspective explanatory view of a lamination type battery element showing other examples of composition of a battery element used for a battery pack of the present invention. It is plane explanatory drawing (A) and longitudinal cross-sectional explanatory drawing (B) which show the reference example of the battery pack of this invention. FIG. 16 is an explanatory plan view showing another configuration example of the battery pack of FIG. 15.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Battery element, 11 ... Positive electrode, 12 ... Negative electrode, 13a, 13b ... Separator, 14 ... Gel electrolyte, 15a ... Positive electrode terminal, 15b ... Negative electrode terminal, 17 ... Laminate film, 18 ... Battery exterior material, 20 ... Battery, 30 ... Battery pack, 32 ... Protection circuit board, 35 ... Spacer, 35A ... Projection, 35B ... Positioning mark, C ... Mold for molding

Claims (10)

A rectangular plate-shaped battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode with a separator interposed between them and a protective circuit board of the battery is mounted on the maximum surface of the six planes of the battery. Through a spacer arranged on a pair of surfaces, set at a predetermined position in the molding space of the mold,
By filling and curing the exterior material in the molding space of the mold, the battery and the protection circuit board are integrally covered with the exterior material,
The method for producing a battery pack, wherein the spacer includes at least one resin material selected from polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene, and polyethylene. A rectangular plate-shaped battery in which a battery element formed by winding or laminating a positive electrode and a negative electrode with a separator interposed between them and a protective circuit board of the battery is the largest of the six planes of the battery. It is set at a predetermined position in the molding space of the molding die through spacers arranged on a pair of surfaces,
The battery and the protective circuit board are integrally covered with the exterior material filled and cured in the molding space of the mold,
The battery pack, wherein the spacer includes at least one resin material selected from polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene, and polyethylene.   The battery pack according to claim 2, wherein the exterior material is a composite material including a shape maintaining polymer and a filler material. The battery pack according to claim 3 , wherein the shape maintaining polymer is a resin selected from a urethane resin, an acrylic resin, and an epoxy resin.   5. The spacer according to claim 2, wherein the spacer has a cylindrical shape, a prismatic shape, a rectangular parallelepiped shape, a truncated cone shape, a truncated pyramid shape, a net shape, a cross shape, or a shape similar to these shapes. The battery pack described in 1. The battery pack according to any one of claims 2 to 5, wherein the packaging body for packaging the battery element is a single-layer or double-layer film, and includes an aluminum laminate film or a polyolefin film. The filler material includes silicon (Si), aluminum (Al), titanium (Ti), zirconium (Zr), zinc (Zn), magnesium (Mg) oxide, and any mixture of these oxides. The battery pack according to any one of claims 3 and 4 , which is any metal oxide filler.   The battery pack according to any one of claims 2 to 7, wherein a buffer material is formed integrally with the battery.   The buffer material is at least one resin material selected from polycarbonate, acrylonitrile-butadiene-styrene resin (ABS), polypropylene and polyethylene, at least one metal material selected from aluminum and stainless steel, and the metal material to the resin material. The battery pack according to claim 8, comprising any of insert-molded materials.   The battery pack according to any one of claims 2 to 9, wherein the battery element includes a gel electrolyte.

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