JP6303780B2 - Batteries and electronics - Google Patents

Description

  The present technology relates to a battery including a battery element and an exterior material that covers the battery element, and an electronic device including the battery.

  In recent years, a battery having the following configuration has been proposed as a power source for portable electronic devices and the like (see, for example, Patent Document 1). That is, the exterior material is composed of first and second laminate materials having substantially the same size, the battery element is accommodated in the recess formed in the first laminate material, and the second laminate material covers the opening of the recess. The first and second laminates are overlaid and the periphery of the opening is sealed. On the outside of the bottom surface of the concave portion of the first laminate material, both end portions of the first and second laminate materials are joined, and the both side surfaces are shaped into an ellipse that swells outward.

JP 2005-166650 A

  In the battery having the above-described configuration, when a heavy load is applied to the battery, the battery may be broken in half. In this case, there is a possibility that the broken part of the exterior material may pierce the battery element and the battery element may be short-circuited. Thus, when a battery element short-circuits, a battery element may run out of heat.

  Therefore, an object of the present technology is to provide a battery that can improve safety and an electronic device including the battery.

In order to solve the above-mentioned problem, the first technique is:
A battery element having a flat shape or a square shape ;
While containing a battery element, an exterior material having an opening;
A cover body provided in the opening,
The exterior material includes a metal layer,
The cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided in the center of the surface,
The joint is a battery that is provided on the main surface of the battery element and that is located at a position facing or substantially facing the recess.

The second technology is
A battery element having a flat shape or a square shape ;
An exterior material containing the battery element and having a first opening and a second opening;
A first cover body provided in the first opening;
A second cover body provided in the second opening;
With
The exterior material includes a metal layer,
At least one of the first cover body and the second cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided in the center of the surface,
The joint is a battery that is provided on the main surface of the battery element and that is located at a position facing or substantially facing the recess.

The third technology is
A battery element having a flat shape or a square shape ;
While containing a battery element, an exterior material having an opening;
A cover body provided in the opening,
The exterior material includes a metal layer,
The cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided in the center of the surface,
The seam is provided on the main surface of the battery element and includes a battery at a position facing the recess or a position substantially facing the recess,
An electronic device that is supplied with power from a battery.

The fourth technology is
A battery element having a flat shape or a square shape ;
An exterior material containing the battery element and having a first opening and a second opening;
A first cover body provided in the first opening;
A second cover body provided in the second opening;
With
The exterior material includes a metal layer,
At least one of the first cover body and the second cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided in the center of the surface,
The seam is provided on the main surface of the battery element and includes a battery at a position facing the recess or a position substantially facing the recess,
An electronic device that is supplied with power from a battery.

  As described above, according to the present technology, the safety of the battery can be improved.

FIG. 1 is a perspective view showing an example of the appearance of a battery according to the first embodiment of the present technology. FIG. 2 is an exploded perspective view showing an example of the configuration of the battery according to the first embodiment of the present technology. FIG. 3A is a perspective view showing an example of the appearance of the battery element. FIG. 3B is a schematic cross-sectional view showing an example of the configuration of the battery element. FIG. 4A is a development view illustrating an example of the configuration of the exterior material. 4B is a side view of the exterior material shown in FIG. 4A. 4C is a rear view of the exterior material shown in FIG. 4A. FIG. 5 is a perspective view showing an example of the shape of the exterior member that houses the battery element. FIG. 6A is a schematic cross-sectional view illustrating an example of a configuration of a soft laminate material. FIG. 6B is a schematic cross-sectional view showing an example of the configuration of the hard laminate material. FIG. 6C is a schematic cross-sectional view illustrating an example of the configuration of the joint of the exterior material. FIG. 7A is a perspective view showing an example of the shape of the top cover body. FIG. 7B is a cross-sectional view showing an example of a cross section taken along the line AA of FIG. 7A. 8A is a cross-sectional view showing an example of a cross section taken along the line AA of FIG. 8B is a cross-sectional view showing another example of a cross section taken along the line AA of FIG. FIG. 9A is a perspective view showing an example of the shape of the bottom cover. FIG. 9B is a cross-sectional view showing an example of a cross section taken along line AA of FIG. 9A. 10A to 10F are perspective views illustrating an example of the appearance of a battery according to a modification of the first embodiment of the present technology. FIG. 11 is a block diagram illustrating an example of a configuration of an electronic device according to the second embodiment of the present technology.

  The joint of the exterior material is preferably configured by bringing the sides of the exterior material into contact with each other or arranging the sides of the exterior material slightly separated from each other. When the exterior material includes the first exterior material and the second exterior material, and the battery has the joint of the first exterior material and the joint of the second exterior material, the first exterior material and the second exterior material Of the exterior materials, it is preferable that the seam of the harder one is provided at a position facing the recess or a position substantially facing the recess.

It is preferable that the exterior material has an opening at one end or both ends of the battery element, for example. When the exterior material has openings at both ends, it is preferable that a cover body is provided in each of the openings. When cover bodies are provided at both ends of the exterior material, it is preferable that at least one of the cover bodies has a recess on the surface facing the joint of the exterior material, and both of the cover bodies are More preferably, the surface has a recess.

Embodiments of the present technology will be described in the following order with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals.
1 First Embodiment (Example of Battery)
1.1 Configuration of Battery 1.2 Battery Manufacturing Method 1.3 Effect 1.4 Modification 2 Second Embodiment (Example of Electronic Device)
2.1 Configuration of electronic equipment 2.2 Effects

<1 First Embodiment>
[1.1 Battery configuration]
As shown in FIGS. 1 and 2, the battery according to the first embodiment of the present technology includes a battery element 1, an exterior material 2 that covers the battery element 1, and has openings at both ends, and an exterior material 2. A top cover (first cover body) 3 and a bottom cover (second cover body) 4 fitted to the openings at both ends are provided. As shown in FIG. 2, the battery may further include a label 6 that is a surface member, and the surface of the exterior member 2 may be covered with the label 6.

  The battery has a flat shape having two main surfaces, and a seam L1 of the exterior material 2 is provided on one main surface. The top cover 3 includes a positive terminal 3h, a negative terminal 3i, and an identification terminal 3j. A positive electrode lead 5 a and a negative electrode lead 5 b are provided on one opening side of the exterior material 2. In the present specification, of the both ends of the battery or battery element 1, the side on which the positive electrode lead 5a and the negative electrode lead 5b are provided is referred to as the top side, and the opposite side is referred to as the bottom side.

  Hereinafter, the battery element 1, the exterior material 2, the top cover 3, the bottom cover 4, and the label 6 will be described.

(Battery element)
As shown in FIG. 3A, the battery element 1 is a wound battery element having a flat shape, for example. The positive electrode lead 5a and the negative electrode lead 5b are led out in the same direction from one end of the battery element 1, for example. The battery element 1 is a so-called lithium ion secondary battery. The positive electrode lead 5a and the negative electrode lead 5b are made of, for example, a metal material such as aluminum, copper, nickel, or stainless steel, and each have a thin plate shape or a mesh shape.

  As shown in FIG. 3B, the battery element 1 includes a positive electrode 11, a negative electrode 12, a separator 13, and an electrolyte layer 14. The positive electrode 11, the negative electrode 12, and the separator 13 have, for example, an elongated rectangular shape. Yes. The battery element 1 has, for example, a winding structure in which the positive electrode 11 and the negative electrode 12 are wound in the longitudinal direction via the separator 13 and the electrolyte layer 14. An electrolyte layer 14 is provided between the positive electrode 11 and the separator 13 and between the negative electrode 12 and the separator 13, respectively.

(Positive electrode)
The positive electrode 11 includes, for example, a positive electrode current collector 11A and a positive electrode active material layer 11B provided on both surfaces of the positive electrode current collector 11A. Although not shown, the positive electrode active material layer 11B may be provided only on one surface of the positive electrode current collector 11A. The positive electrode lead 5a is attached to the positive electrode current collector 11A by welding or the like.

  The positive electrode current collector 11A is made of, for example, a metal foil such as an aluminum foil, a nickel foil, or a stainless steel foil. The positive electrode active material layer 11B includes, for example, one or more positive electrode materials capable of occluding and releasing lithium as a positive electrode active material, and a conductive agent such as graphite and polyfluoride as necessary. It is configured to contain a binder such as vinylidene.

As the positive electrode material capable of inserting and extracting lithium, for example, lithium-containing compounds such as lithium oxide, lithium phosphorous oxide, lithium sulfide, or an intercalation compound containing lithium are suitable. May be used in combination. In order to increase the energy density, a lithium-containing compound containing lithium, a transition metal element, and oxygen (O) is preferable. Examples of such a lithium-containing compound include a lithium composite oxide having a layered rock salt structure shown in Formula (A) and a lithium composite phosphate having an olivine structure shown in Formula (B). Can be mentioned. It is more preferable that the lithium-containing compound includes at least one member selected from the group consisting of cobalt (Co), nickel (Ni), manganese (Mn), and iron (Fe) as a transition metal element. Examples of such a lithium-containing compound include a lithium composite oxide having a layered rock salt type structure represented by the formula (C), formula (D), or formula (E), and a spinel type compound represented by the formula (F). Examples thereof include a lithium composite oxide having a structure, or a lithium composite phosphate having an olivine structure shown in the formula (G). Specifically, LiNi _0.50 Co _0.20 Mn _0.30 O ₂ , Li _a CoO ₂ (A≈1), Li _b NiO ₂ (b≈1), Li _c1 Ni _c2 Co _1-c2 O ₂ (c1≈1, 0 <c2 <1), Li _d Mn ₂ O ₄ (d≈1) or Li _e FePO ₄ (e≈1).

_{Li p Ni (1-qr)} Mn q M1 r O (2-y) X z ··· (A)
(In the formula (A), M1 represents at least one element selected from Groups 2 to 15 excluding nickel (Ni) and manganese (Mn). X represents Group 16 other than oxygen (O)) It represents at least one of elements and group 17. Elements p, q, r, 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.

Li _a M2 _b PO ₄ (B)
(In the formula (B), M2 represents at least one element selected from Groups 2 to 15. a and b are 0 ≦ a ≦ 2.0 and 0.5 ≦ b ≦ 2.0. It is a value within the range.)

Li _f Mn _(1-gh) Ni _g M3 _h O _(2-j) F _k (C)
(However, in formula (C), M3 is cobalt (Co), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe ), Copper (Cu), zinc (Zn), zirconium (Zr), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W) F, g, h, j and k are 0.8 ≦ f ≦ 1.2, 0 <g <0.5, 0 ≦ h ≦ 0.5, g + h <1, −0.1 ≦ j. ≦ 0.2, 0 ≦ k ≦ 0.1 (The composition of lithium varies depending on the state of charge and discharge, and the value of f represents the value in the complete discharge state.)

Li _m Ni _(1-n) M4 _n O _(2-p) F _q (D)
(However, in formula (D), M4 is cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr ), Iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). M, n, p and q are 0.8 ≦ m ≦ 1.2, 0.005 ≦ n ≦ 0.5, −0.1 ≦ p ≦ 0.2, 0 ≦ q ≦ 0.1. (Note that the composition of lithium varies depending on the state of charge and discharge, and the value of m represents a value in a fully discharged state.)

Li _r Co _(1-s) M5 _s O _{(2-t) Fu} (E)
(However, in formula (E), M5 is nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr ), Iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). R, s, t, and u are ranges of 0.8 ≦ r ≦ 1.2, 0 ≦ s <0.5, −0.1 ≦ t ≦ 0.2, and 0 ≦ u ≦ 0.1. (Note that the composition of lithium varies depending on the state of charge and discharge, and the value of r represents a value in a fully discharged state.)

Li _v Mn _2-w M6 _w O _x F _y (F)
(However, in formula (F), M6 is cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr ), Iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). V, w, x, and y are in the range of 0.9 ≦ v ≦ 1.1, 0 ≦ w ≦ 0.6, 3.7 ≦ x ≦ 4.1, and 0 ≦ y ≦ 0.1. (Note that the composition of lithium varies depending on the state of charge and discharge, and the value of v represents the value in a fully discharged state.)

Li _z M7PO ₄ (G)
(However, in formula (G), M7 is cobalt (Co), manganese (Mn), iron (Fe), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti ), Vanadium (V), niobium (Nb), copper (Cu), zinc (Zn), molybdenum (Mo), calcium (Ca), strontium (Sr), tungsten (W) and zirconium (Zr) Z represents a value in a range of 0.9 ≦ z ≦ 1.1, wherein the composition of lithium varies depending on the state of charge and discharge, and the value of z is a value in a fully discharged state. Represents.)

In addition to these, positive electrode materials capable of inserting and extracting lithium include inorganic compounds not containing lithium, such as MnO ₂ , V ₂ O ₅ , V ₆ O ₁₃ , NiS, and MoS.

  The positive electrode material capable of inserting and extracting lithium may be other than the above. Moreover, the positive electrode material illustrated above may be mixed 2 or more types by arbitrary combinations.

(Negative electrode)
The negative electrode 12 includes, for example, a negative electrode current collector 12A and a negative electrode active material layer 12B provided on both surfaces of the negative electrode current collector 12A. Although not shown, the negative electrode active material layer 12B may be provided only on one surface of the negative electrode current collector 12A. The negative electrode lead 5b is attached to the negative electrode current collector 12A by welding or the like.

  The negative electrode current collector 12A is made of, for example, a metal foil such as a copper foil, a nickel foil, or a stainless steel foil. The negative electrode active material layer 12B includes one or more negative electrode materials capable of occluding and releasing lithium as the negative electrode active material, and the positive electrode active material layer 11B as necessary. It is comprised including the binder similar to.

  In this battery, the electrochemical equivalent of the negative electrode material capable of inserting and extracting lithium is larger than the electrochemical equivalent of the positive electrode 11 so that lithium metal does not deposit on the negative electrode 12 during charging. It has become.

  Examples of the negative electrode material capable of inserting and extracting lithium include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, glassy carbons, and fired organic polymer compounds And carbon materials such as carbon fiber and activated carbon. As graphite, it is preferable to use spheroidized natural graphite or substantially spherical artificial graphite. As the artificial graphite, artificial graphite obtained by graphitizing mesocarbon microbeads (MCMB) or artificial graphite obtained by graphitizing and pulverizing a coke raw material is preferable. Examples of the coke include pitch coke, needle coke, and petroleum coke. An organic polymer compound fired body refers to a carbonized material obtained by firing a polymer material such as phenol resin or furan resin at an appropriate temperature, and part of it is non-graphitizable carbon or graphitizable carbon. Some are classified as: Examples of the polymer material include polyacetylene and polypyrrole. These carbon materials are preferable because the change in crystal structure that occurs during charge and discharge is very small, a high charge and discharge capacity can be obtained, and good cycle characteristics can be obtained. In particular, graphite is preferable because it has a high electrochemical equivalent and can provide a high energy density. Further, non-graphitizable carbon is preferable because excellent characteristics can be obtained. Furthermore, those having a low charge / discharge potential, specifically, those having a charge / discharge potential close to that of lithium metal are preferable because a high energy density of the battery can be easily realized.

  Examples of the negative electrode material capable of inserting and extracting lithium include materials capable of inserting and extracting lithium and containing at least one of a metal element and a metalloid element as a constituent element. Here, the negative electrode 12 including such a negative electrode material is referred to as an alloy-based negative electrode. This is because a high energy density can be obtained by using such a material. In particular, the use with a carbon material is more preferable because a high energy density can be obtained and excellent cycle characteristics can be obtained. The negative electrode material may be a single element, alloy or compound of a metal element or metalloid element, or may have at least a part of one or more of these phases. In the present technology, the alloy includes an alloy including one or more metal elements and one or more metalloid elements in addition to an alloy composed of two or more metal elements. Moreover, the nonmetallic element may be included. Some of the structures include a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or two or more of them.

  Examples of metal elements or metalloid elements constituting the negative electrode material include magnesium (Mg), boron (B), aluminum (Al), gallium (Ga), indium (In), silicon (Si), and germanium (Ge). ), Tin (Sn), lead (Pb), bismuth (Bi), cadmium (Cd), silver (Ag), zinc (Zn), hafnium (Hf), zirconium (Zr), yttrium (Y), palladium (Pd) ) Or platinum (Pt). These may be crystalline or amorphous.

  Among these, as the negative electrode material, a material containing a 4B group metal element or a semimetal element in the short-period type periodic table as a constituent element is preferable, and at least one of silicon (Si) and tin (Sn) is particularly preferable. It is included as an element. This is because silicon (Si) and tin (Sn) have a large ability to occlude and release lithium (Li), and a high energy density can be obtained.

  As an alloy of tin (Sn), for example, as a second constituent element other than tin (Sn), silicon (Si), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), and chromium (Cr) The thing containing at least 1 sort is mentioned. As an alloy of silicon (Si), for example, as a second constituent element other than silicon (Si), tin (Sn), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc (Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), and chromium (Cr). The thing containing 1 type is mentioned.

  Examples of the tin (Sn) compound or silicon (Si) compound include those containing oxygen (O) or carbon (C). In addition to tin (Sn) or silicon (Si), the above-described compounds are used. Two constituent elements may be included.

Examples of the negative electrode material capable of inserting and extracting lithium further include other metal compounds or polymer materials. Examples of other metal compounds include oxides such as MnO ₂ , V ₂ O ₅ , and V ₆ O ₁₃ , sulfides such as NiS and MoS, and lithium nitrides such as LiN ₃ , and polymer materials include polyacetylene. , Polyaniline or polypyrrole.

(Separator)
The separator 13 separates the positive electrode 11 and the negative electrode 12 and allows lithium ions to pass through while preventing a short circuit of current due to contact between the two electrodes. The separator 13 is made of, for example, a porous film made of synthetic resin made of polytetrafluoroethylene, polypropylene, polyethylene, or the like, or a porous film made of ceramic, and these two or more kinds of porous films are laminated. It may be a structure. Among these, a porous film made of polyolefin is preferable because it is excellent in the effect of preventing short circuit and can improve the safety of the battery due to the shutdown effect. In particular, polyethylene is preferable as a material constituting the separator 13 because a shutdown effect can be obtained in a range of 100 ° C. or higher and 160 ° C. or lower and the electrochemical stability is excellent. Polypropylene is also preferable. In addition, any resin having chemical stability can be used by copolymerizing or blending with polyethylene or polypropylene.

(Electrolyte layer)
The electrolyte layer 14 includes a non-aqueous electrolyte and a polymer compound serving as a holding body that holds the non-aqueous electrolyte, and the polymer compound is swollen by the non-aqueous electrolyte. The content ratio of the polymer compound can be adjusted as appropriate. The electrolyte layer 14 having such a configuration is preferably a gel electrolyte layer. This is because high ion conductivity can be obtained and battery leakage can be prevented.

The non-aqueous electrolyte contains, for example, a solvent and an electrolyte salt. Examples of the solvent include 4-fluoro-1,3-dioxolan-2-one, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, and γ-valerolactone. 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, methyl acetate, methyl propionate, ethyl propionate, acetonitrile, glutaronitrile, adiponitrile, methoxy acetonitrile, 3-methoxy propyl Oh nitrile, N, N- dimethylformamide, N- methylpyrrolidinone, N- methyl oxazolidinone, nitromethane, nitroethane, sulfolane, dimethyl sulfoxide, trimethyl phosphate, Li Room temperature molten salts such as triethyl phosphate, ethylene sulfite, and bistrifluoromethylsulfonylimide trimethylhexylammonium. Among them, at least one of the group consisting of 4-fluoro-1,3-dioxolan-2-one, ethylene carbonate, propylene carbonate, vinylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and ethylene sulfite is used as a mixture. It is preferable because excellent charge / discharge capacity characteristics and charge / discharge cycle characteristics can be obtained. The electrolyte layer 14 may contain a known additive in order to improve battery characteristics.

The electrolyte salt may contain one kind or a mixture of two or more kinds of materials. Examples of the electrolyte salt include lithium hexafluorophosphate (LiPF ₆ ), lithium bis (pentafluoroethanesulfonyl) imide (Li (C ₂ F ₅ SO ₂ ) 2N), lithium perchlorate (LiClO ₄ ), six Lithium fluoroarsenate (LiAsF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium trifluoromethanesulfonate (LiSO ₃ CF ₃ ), lithium bis (trifluoromethanesulfonyl) imide (Li (CF ₃ SO ₂ ) ₂ N), tris (trifluoromethanesulfonyl) methyllithium (LiC (SO ₂ CF ₃ ) ₃ ), lithium chloride (LiCl) and lithium bromide (LiBr).

  Examples of the polymer compound include polyacrylonitrile, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, and polysiloxane. , Polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene or polycarbonate. In particular, polyacrylonitrile, polyvinylidene fluoride, polyhexafluoropropylene or polyethylene oxide is preferable from the viewpoint of electrochemical stability.

(Exterior material)
The exterior material is composed of a laminate material such as a laminate film. Specifically, as shown in FIGS. 4A to 4C, the exterior material 2 includes a soft laminate material (first exterior material) 2 a provided with an accommodating portion 25 for accommodating the battery element 1, and the soft material. And a hard laminate material (second exterior material) 2b stacked on the laminate material 2a so as to cover the housing portion 25. The accommodating part 25 has a concave shape with respect to one surface of the soft laminate material 2a. Around the housing portion 25, the soft laminate material 2a and the hard laminate material 2b are bonded together by heat welding or the like. A heat welding sheet 25 a is provided on the protruding surface 2 </ b> S on the back side of the bottom surface of the housing portion 25.

  The soft laminate material 2a is suitable for forming the accommodating portion 25 into which the battery element 1 is inserted by deep drawing and is preferably softer than the hard laminate material 2b. As shown in FIG. 6A, the soft laminate 2a has a laminated structure in which a bonding layer 26a, a metal layer 27a, and a surface protective layer 28a are sequentially laminated. In a state in which the exterior material 1 is closed, the bonding layer 26a becomes the outside (side in contact with the hard laminate material 2b).

  The bonding layer 26a has a function of being melted by heat, ultrasonic waves, or the like and welded to the hard laminate material 2b or the like. As a material of the bonding layer 26a, a material that does not cause alteration such as a polymer electrolyte contained in the battery element 1 is preferable. As such a material, for example, polypropylene such as non-axially stretched polypropylene (CPP) can be used. The thickness of the bonding layer 26a is selected to be about 30 μm, for example.

  The metal layer 27a has a function of preventing moisture from entering the battery. As a material of the metal layer 27a, for example, annealed aluminum (JIS A8021P-O) or (JIS A8079P-O) can be used. Further, the thickness of the metal layer 27a is selected in a range of about 30 μm to 130 μm, for example.

  The surface protective layer 28a has a function of protecting the surface of the soft laminate material 2a. As a material for the surface protective layer 28a, for example, nylon, polyethylene terephthalate (PET), or the like can be used. The thickness of the surface protective layer 28a is selected in the range of about 10 to 30 μm, for example.

  It is preferable that the hard laminate material 2b can maintain the shape after bending and can withstand deformation from the outside. The hard laminate material 2b is harder than the soft laminate material 2a. As shown in FIG. 6B, the hard laminate material 2b has a laminated structure in which a bonding layer 26b, a metal layer 27b, and a surface protective layer 28b are sequentially laminated. In a state where the exterior material 2 is closed, the bonding layer 26b is on the inner side (side in contact with the soft laminate material 2a).

  The bonding layer 26b and the surface protective layer 28b of the hard laminate material 2b are respectively the same as the bonding layer 26a and the surface protective layer 28a of the soft laminate material 2a. The metal layer 27b is harder than the metal layer 27a. For the metal layer 27b, for example, aluminum (JIS A3003P-H18) or (JIS A3004P-H18) without annealing treatment can be used. Moreover, the thickness of the metal layer 27b is selected in the range of about 30 μm to 130 μm, for example. The thickness of each layer of the soft laminate material 2a and the hard laminate material 2b is preferably selected in consideration of the total thickness.

  As shown in FIG. 4A, the soft laminate material 2a and the hard laminate material 2b have a substantially rectangular shape, and are overlapped in the longitudinal direction. That is, a laminated region 2Ra where only the soft laminate material 2a exists is provided at one end in the longitudinal direction of the overlapped soft laminate material 2a and hard laminate material 2b, and only the hard laminate material 2b exists at the other end. A bonding region 2Rb to be provided is provided. These bonding regions 2Ra and 2Rb are formed on the main surface of the battery element 1 covered with the soft laminate material 2a, that is, the bottom surface of the housing portion 25, in a state where the hard laminate material 2b is curved and closed. Are combined on the projecting surface 2S on the back side of the film, and bonded by heat welding or the like.

  The heat welding sheet 25a is an auxiliary member for bonding the surface protective layers 28a of the soft laminate material 2a facing each other on the projecting surface 2S on the back side of the bottom surface of the housing portion 25. The thickness of the heat-welded sheet 25a is preferably about 10 to 60 μm in consideration of the total thickness of the exterior material 2. As a material of the heat-bonding sheet 25a, a material having a melting point in a temperature range that does not affect the battery element 1 is preferable. For example, a material having a melting point of about 100 degrees is used.

  The width in the short direction of the soft laminate 2a is narrower than the width in the short direction of the hard laminate 2b. A laminated region 2Rc in which only the hard laminate material 2b exists is provided at one end in the short direction of the overlapped soft laminate material 2a and hard laminate material 2b, and this one end side is the top side. The bonding layer 26b of the hard laminate material 2b in the bonding region 2Rc is bonded to the peripheral surface of the top cover 3 by heat welding or the like in a state where the exterior material 2 is closed. On the other hand, such a bonding region is not provided at the other end, and the end portions of the soft laminate material 2a and the hard laminate material 2b coincide with each other, and the other end is the bottom side. In addition, the bonding area | region in which only the hard laminate material 2b exists is provided also in the other end, and the bottom cover 4 in the state which the bonding layer 26b of the hard laminate material 2b in this bonding area | region closed the exterior material 2. You may make it bond by the surrounding surface of this, and heat welding.

  The soft laminate material 2a is a soft laminate film having flexibility, for example. The soft laminate material 2a has a substantially rectangular shape. Specifically, the soft laminate 2a has long sides 21a and 22a that are a set of sides having the same length, and short sides 23a and 24a that are a set of sides having the same length.

  The hard laminate material 2b is a hard laminate film having flexibility, for example. The hard laminate material 2b has a substantially rectangular shape. Specifically, the hard laminate material 2b has long sides 21b and 22b which are a set of sides having the same length, and short sides 23b and 24b which are a set of sides having the same length.

  The short side 23a of the soft laminate 2a is arranged outside the short side 23b of the hard laminate 2b, and the short side 24a of the soft laminate 2a is arranged inside the short side 24b of the hard laminate 2b. . Thereby, bonding area | region 2Ra, 2Rb mentioned above is each provided in the both ends of the longitudinal direction of the laminated soft laminate material 2a and the hard laminate material 2b.

  The lengths of the long sides 21b and 22b of the hard laminate material 2b are set so that the short sides 23b and 24b are in contact with each other or face each other with a slight gap therebetween when the exterior material 2 is closed. . The lengths of the long sides 21a and 22a of the soft laminate 2a are selected to be shorter than the lengths of the long sides 21b and 22b of the hard laminate 2b. For example, when the exterior material 2 is closed, the short sides 23a and 24a Are set to touch each other or to face each other at an interval. Here, the gap between the soft laminates 2a is not limited to a slight width, and may have a certain width.

  The lengths of the short sides 23a and 24a of the soft laminate 2a are slightly shorter than the lengths of the short sides 23b and 24b of the hard laminate 2b. Thereby, the soft laminate material 2a and the hard laminate material 2b are overlapped so that only the hard laminate material 2b exists on the top side, and the bonding region 2Rc is provided on the top side.

  As shown in FIG. 5, the seam L <b> 1 and the seam L <b> 2 are formed on the main surface of the battery element 1 covered with the soft laminate material 2 a in a state where the exterior material 2 is closed. Specifically, on the protruding surface 2S on the back side of the bottom surface of the housing portion 25, the short sides 23b and 24b of the hard laminate material 2b are in contact with each other or are slightly separated from each other so as to be hard on the housing portion 25. A seam L1 of the laminate material 2b is configured. Further, the short sides 23a and 24a of the soft laminate material 2a are also in contact with each other or are slightly separated from each other, thereby forming a joint L2 of the soft laminate material 2a on the housing portion 25. It is preferable that the joint L1 of the soft laminate material 2a is provided at the center of the battery main surface (that is, the main surface of the battery element 2) or substantially at the center.

  As shown in FIG. 6C, on the protruding surface 2S on the back side of the bottom surface of the accommodating portion 25, the bonding regions 2Ra and 2Rb are overlapped with each other and the bonding layer 26a of the soft laminate material 2a and the hard laminate material 2b arranged to face each other. The bonding layer 26b is bonded by thermal welding or the like. Further, on the protruding surface 2S on the back side of the bottom surface of the housing portion 25, the surface protective layer 28a of the soft laminate material 2a constituting the protruding surface 2S and the surface protective layers 28a at both ends of the folded soft laminate material 2a are: It is bonded by heat welding or the like via the heat welding sheet 25a.

It is preferable that one end or both ends of the pair of sides 23b and 24b included in the joint L1 of the exterior material 2 have a shape without corners. In addition, it is preferable that one end or both ends of the pair of sides 23a and 24a included in the joint L2 of the exterior material 2 have a shape without corners. Examples of the shape having no corner include a curved shape such as an R shape or a substantially R shape, and a rounded shape such as a C shape. However, the shape is not limited thereto. Here, the R shape includes not only an arc shape but also an elliptical arc shape. The C shape refers to a shape obtained by cutting off right-angle corners in a straight line.

(label)
The label 6 is a nameplate for displaying, for example, information on handling and safety standards on the surface of the exterior material 2, such as letters and designs. The label 6 includes a substrate having a film shape, an adhesive layer, an ink layer, and a UV coating layer sequentially laminated on one main surface of the substrate, and an adhesive layer laminated on the other main surface. Is provided. As the base material, for example, a PET base material mainly composed of polyethylene terephthalate (PET) can be used. However, the base material is not particularly limited, and is appropriately selected according to the desired label 6 characteristics. Can do. The label 6 is bonded to the exterior material 2 through the adhesive layer. The label 6 may cover only one main surface of the battery provided with the joint L1, or may cover the entire peripheral surface of the battery.

(Top cover)
The top cover 3 is fitted into the top side opening of the exterior material 2 and closes the top side opening. As shown in FIG. 2, the top cover 3 includes a top cover body 31, a circuit board 32, a positive electrode tab 33 a and a negative electrode tab 33 b, and a holder 34.

  The positive electrode lead 5a drawn out from the battery element 1 is connected to the circuit board 32 via the positive electrode tab 33a. The negative electrode lead 5b drawn out from the battery element 1 is connected to the circuit board 32 via the negative electrode tab 33b. Mounted on the circuit board 32 are, for example, a protection circuit including a temperature protection element such as a fuse, a thermal resistance element (Positive Temperature Coefficient: PTC), a thermistor, and an ID resistor for identifying a battery. Further, the protection circuit includes a charge / discharge control FET (Field Effect Transistor) and an IC (Integrated Circuit) that monitors the battery element 1 and controls the charge / discharge control FET.

  The PTC is connected in series with the battery element 1, and when the temperature of the battery element 1 becomes higher than the set temperature, the electrical resistance increases rapidly and substantially blocks the current flowing through the battery element 1. A fuse and a thermistor are also connected in series with the battery element 1, and when the temperature of the battery element 1 becomes higher than the set temperature, the current flowing through the battery element 1 is cut off. If the terminal voltage of the battery element 1 exceeds, for example, a predetermined voltage (for example, 4.3 V to 4.4 V), an abnormal state such as thermal runaway may occur. Therefore, the protection circuit monitors the voltage of the battery element 1. When the voltage exceeds a predetermined voltage, the charge control FET is turned off and charging is prohibited. When the terminal voltage of the battery element 1 is overdischarged to a voltage lower than the discharge prohibition voltage and the secondary battery voltage becomes 0V, the battery element 1 may be in an internal short circuit state and may not be recharged. 1 is monitored, and when the voltage falls below the discharge inhibition voltage, the discharge control FET is turned off and discharge is inhibited.

  As shown to FIG. 7A, the top cover main body 31 has the surface S11, the back surface S12 on the opposite side to this surface S11, and the surrounding surface S13 between those surface S11 and the back surface S12.

  The surface S <b> 11 forms an end surface (front surface) on the top side of the battery in a state where the top cover 3 is fitted in the top side opening of the exterior material 2. As shown in FIG. 2 and FIG. 7A, the surface S <b> 11 of the top cover main body 31 has substantially the same shape as the top-side opening of the exterior material 2. More specifically, the surface S11 of the top cover body 31 has a shape that is curved so that both short sides of an elongated rectangle form an elliptical arc or the like toward the outside.

  The back surface S <b> 12 faces the top side of the battery element 1 in a state where the top cover body 31 is fitted into the top side opening of the exterior material 2. As shown in FIG. 7B, a housing portion 31a is provided on the back surface S12. In the housing portion 31a, the circuit board 32, the positive electrode tab 33a, the negative electrode tab 33b, and the like are housed. These housing components are held in the housing portion 31 a of the top cover body 31 by fitting the holder 34 to the top cover body 31.

  The peripheral surface S <b> 13 is a surface that is fitted into the top-side opening of the exterior material 2 and faces the top-side inner circumferential surface of the exterior material 2 in a state where the top cover body 31 is fitted into the top-side opening of the exterior material 2. And close contact. As shown in FIG. 7B, the peripheral surface S13 of the top cover body 31 has a pair of long surfaces S131 and S132 having the same length, and the same length provided on both ends of the long surfaces S131 and S132. And a pair of short surfaces S133 and S134. The lengths of the long surfaces S131 and S132 in the circumferential direction of the circumferential surface S13 are longer than the lengths of the short surfaces S133 and S134 in the circumferential direction of the circumferential surface S13.

  The long surfaces S131 and S132 are, for example, a flat surface or a substantially flat surface, and are positioned on the main surface side of the battery in a state where the top cover body 31 is fitted in the top side opening of the exterior material 2. The short surfaces S133 and S134 are, for example, curved surfaces that are curved in a convex shape, and are positioned on the side surface side of the battery in a state where the top cover body 31 is fitted in the top side opening of the exterior material 2. The boundary between the long surfaces S131 and S132 and the short surfaces S133 and S134 is a position where the shape of the surface changes, for example, a position where the surface changes from a flat surface or a substantially flat surface to a curved surface.

  As shown in FIGS. 7A and 7B, the top cover body 31 has a recess 3a on a long surface S131 of the peripheral surface S13 that faces the joints L1 and L2 of the exterior material 2. The recess 3a is preferably provided in the center or substantially the center of the long surface S131. The recessed part 3a is a groove part extended in the thickness direction (namely, width direction of peripheral surface S13) of the top cover main body 31, for example. This groove portion preferably penetrates the top cover body 31 in the thickness direction. The cross-sectional shape of the recess 3a when the top cover body 31 is cut in a direction perpendicular to the thickness direction of the top cover body 31 (that is, a direction perpendicular to the width direction of the peripheral surface S13) is, for example, a V shape.

  The seam L1 of the hard laminate material 2b is provided at a position facing the recess 3a as shown in FIG. 8A, or is provided at a position almost facing the recess 3a as shown in FIG. 8B. Is preferred. This is because when the battery is folded around the concave portion 3 a, the hard laminate material 2 b is broken, and the broken portion can be prevented from piercing the battery element 1.

  Here, the position substantially opposite to the recess 3a is a position within ± 10% of the battery width D (see FIG. 5) in the longitudinal direction of the long surface S131 with respect to the position P1 of the recess 3a (± (D [ m] × 0.1). For example, when the battery width D is 30 mm, the position substantially facing the recess 3a means a position within ± 3 mm in the longitudinal direction of the long surface S131 with respect to the position P1 of the recess 3a. In addition, the position P1 of the recessed part 3a means the deepest position of the recessed part 3a. When the short sides 23b and 24b of the hard laminate material 2b are arranged slightly separated from each other, the position P2 of the joint L1 of the hard laminate material 2b is an intermediate position between the short sides 23b and 24b. To do.

  As shown in FIGS. 7A and 7B, the top cover main body 31 has recesses 3m and 3n at portions between one long surface S131 and short surfaces S133 and S134 on both sides thereof, respectively. On the other hand, as shown in FIGS. 2 and 5, the exterior material 2 has notches 2 m and 2 n at both ends of the top opening. In a state where the top cover 3 is fitted into the top side opening of the exterior material 2, the notches 2 m and 2 n of the exterior material 2 are positioned on the recesses 3 m and 3 n of the top cover body 31, respectively. Thereby, the recessed parts 3m and 3n of the top cover main body 31 are exposed from the exterior material 2 through the notch parts 2m and 2n, respectively. These recesses 3m and 3n are used on the device side where the battery is loaded to prevent reverse loading of the battery in the positive and negative directions.

  The shape of the recesses 3m and 3n provided on both sides of the long surface S131 of the top cover body 31 is not particularly limited, but is preferably a shape taking into account the degree of design freedom on the device side. A concave shape such as a staircase shape descending in the longitudinal direction of the long surface S131.

(Bottom cover)
The bottom cover 4 is fitted into the bottom side opening of the exterior material 2 and closes the bottom side opening. As shown in FIG. 9A, the bottom cover 4 includes a lid portion 41 and a fitting portion 42. The cover part 41 has the surface S21 and the back surface S22 on the opposite side to this surface S21. The surface S <b> 21 constitutes an end surface (back surface) on the bottom side of the battery in a state where the bottom cover 4 is fitted into the bottom side opening of the exterior material 2.

  The surface S <b> 21 of the lid 41 has substantially the same shape as the bottom side opening of the exterior material 2. More specifically, the surface S21 of the bottom cover 4 has a shape that is curved so that both short sides of an elongated rectangle form an elliptical arc or the like toward the outside. The back surface S <b> 22 faces the bottom side of the battery element 1 in a state where the bottom cover 4 is fitted into the bottom side opening of the exterior material 2.

  A fitting portion 42 is provided on the back surface S22. The fitting part 42 has a peripheral surface S23. The circumferential surface S <b> 23 is a surface that is fitted into the bottom side opening of the exterior material 2, and faces the bottom side inner circumferential surface of the exterior material 2 in a state where the bottom cover 4 is fitted into the bottom side opening of the exterior material 2. And adhere closely.

  The peripheral edge portion of the lid portion 41 slightly protrudes from the peripheral surface S23 of the fitting portion 42. The protruding width is selected to be approximately the thickness of the exterior material 2. Thereby, in a state where the bottom cover 4 is fitted to the bottom side opening of the exterior material 2, the lid portion 41 covers the bottom side opening, and a step is formed between the peripheral portion of the lid portion 41 and the peripheral surface of the exterior material 2. There is no, both are connected in a flat state. The peripheral edge portion of the lid portion 41 may protrude continuously over the entire circumference of the peripheral surface S23 of the fitting portion 42, or may partially protrude within the circumference.

  As shown in FIG. 9B, the peripheral surface S23 of the fitting portion 42 has a pair of long surfaces S231 and S232 having the same length and the same length provided on both ends of the long surfaces S231 and S232. It has a pair of short surfaces S233 and S234. The lengths of the long surfaces S231 and S232 in the circumferential direction of the circumferential surface S23 are longer than the lengths of the short surfaces S233 and S234 in the circumferential direction of the circumferential surface S23.

  The long surfaces S231 and S232 are, for example, a flat surface or a substantially flat surface, and are positioned on the main surface side of the battery in a state where the bottom cover 4 is fitted into the bottom-side opening of the exterior material 2. The short surfaces S233 and S234 are, for example, curved surfaces that are curved in a convex shape, and are located on the side surface side of the battery in a state where the bottom cover 4 is fitted into the bottom side opening of the exterior material 2. The boundary between the long surfaces S231 and S232 and the short surfaces S233 and S234 is a position where the shape of the surface changes, for example, a position where the surface changes from a flat surface or a substantially flat surface to a curved surface.

  As shown in FIGS. 9A and 9B, the bottom cover 4 has a recess 4a on a long surface S231 of the peripheral surface S23 facing the joints L1 and L2 of the exterior material 2. The recess 4a is preferably provided in the center or substantially the center of the long surface S231. The recessed part 4a is a groove part extended in the thickness direction (namely, width direction of peripheral surface S23) of the bottom cover 4, for example. It is preferable that the groove portion penetrates the bottom cover 4 in the thickness direction. The cross-sectional shape of the recess 4a when the bottom cover 4 is cut in a direction perpendicular to the thickness direction of the bottom cover 4 (that is, a direction perpendicular to the width direction of the peripheral surface S23) is, for example, a V shape. The joint L1 of the hard laminate material 2b is preferably provided at a position facing the recess 4a or at a position substantially facing the recess 4a.

  Further, the bottom cover 4 is provided with one or more, preferably two or more through holes (not shown) penetrating from the surface facing the battery element 1 toward the surface opposite thereto. Yes. When two or more through holes are provided, at least one through hole can be used for venting air between the battery element 1 and the bottom cover 4 at the time of resin injection. Fillability can be improved.

[1.2 Battery Manufacturing Method]
Next, an example of a method for manufacturing a battery according to the first embodiment of the present technology will be described.

(Battery element manufacturing process)
First, for example, the positive electrode 11 and the negative electrode 12 having the electrolyte layer 14 formed on both surfaces, and the separator 13 are sequentially laminated in the order of the negative electrode 12, the separator 13, the positive electrode 11, and the separator 13 to form a laminate. Next, the laminate is wound around a flat core and wound many times in the longitudinal direction to produce a wound battery element 1.

(Battery element exterior process)
Next, the accommodating part 25 is formed in the soft laminate material 2a by deep drawing. At this time, as shown in FIG. 4A, the accommodating portion 25 is formed at a position slightly shifted to the short side 24a side with respect to the center position of the soft laminate material 2a. Next, the battery element 1 is accommodated in the accommodating portion 25 formed in the soft laminate material 2a.

  Next, as shown in FIG. 4A, the hard laminate material 2b is superposed on the soft laminate material 2a at a position shifted in the longitudinal direction thereof. Thereby, a bonding region 2Ra where only the soft laminate material 2a exists is formed at one end in the longitudinal direction of the overlapped soft laminate material 2a and hard laminate material 2b, and only the hard laminate material 2b is formed at the other end. An existing bonding region 2Rb is formed. In this way, by overlapping the positions, the both ends of the soft laminate material 2a and the hard laminate material 2b are folded toward the projecting surface 2S of the accommodating portion 25, and then the bonding layer 26a of the soft laminate material 2a and the hard laminate are folded. The bonding layer 26b of the material 2b is bonded with a certain width.

  Next, in a state of arrangement as shown in FIG. 4A, the battery element 1 is sealed by thermally welding the periphery of the housing portion 25 in a reduced pressure atmosphere. At this time, the entire part where the bonding layers 26a and 26b overlap may be heat-welded. Next, as shown in FIG. 4A, a heat welding sheet 25 a having a predetermined shape is provided on the protruding surface 2 </ b> S on the back side of the bottom surface of the housing portion 25.

  Next, both ends of the soft laminate material 2a and the hard laminate material 2b, that is, the short sides toward the main surface of the battery element 1 covered with the soft laminate material 2a, that is, the protruding surface 2S on the back side of the bottom surface of the housing portion 25 23a, 24a and short sides 23b, 24b are folded inward. Next, the bonding region 2Ra of the soft laminate material 2a and the bonding region 2Rb of the hard laminate material 2b are thermally welded, and the protruding surface 2S on the back side of the bottom surface of the housing portion 25 is interposed via the heat welding sheet 25a. Then, the soft laminate material 2a is heat-welded. Thereby, as shown in FIG. 5, the soft laminate material 2a and the hard laminate material 2b are fixed in a closed state so as to wrap around the housing portion 25 in which the battery element 1 is housed, and the top side opening and the bottom side opening are formed. It is formed.

  In a state where the battery element 1 is encased, as shown in FIG. 6C, the short sides 23b and 24b of the hard laminate 2b are in contact with each other or are arranged so as to face each other with a slight gap therebetween, thereby forming the joint L1. Is formed. Further, the seam L2 is formed by arranging the short sides 23a and 24a of the soft laminate material 2a so as to be in contact with each other or facing each other while being slightly separated from each other inside the hard laminate material 2b. The seam L2 is not limited to this example, and the short sides 23a and 24a of the soft laminate material 2a may be arranged so as to face each other with a certain distance therebetween.

(Top cover mating process)
Next, the positive electrode lead 5a and the negative electrode lead 5b are attached to the circuit board 32 via the positive electrode tab 33a and the negative electrode tab 33b, respectively, by resistance welding or ultrasonic welding, for example. Next, after the circuit board 32, the positive electrode tab 33 a, the negative electrode tab 33 b, and the like are accommodated in the accommodation portion of the top cover body 31, the holder 34 is fitted to the top cover body 31. Thereby, the top cover 3 is formed.

  Next, the top cover 3 is fitted into the top side opening of the exterior material 2 so that the joint L1 of the exterior material 2 faces the recess 3a of the top cover body 31 while appropriately folding back the positive electrode lead 5a and the negative electrode lead 5b. To do.

(Bottom cover fitting process)
Next, the bottom cover 4 is fitted into the bottom side opening of the exterior material 2 so that the joint L <b> 1 of the exterior material 2 faces the recess 4 a of the bottom cover 4.

(Thermal welding process)
Next, the exterior material 2 is thermally welded while holding the entire length with a jig. Specifically, a heater block made of a metal such as copper is pressed from above and below to the top end of the exterior material 2 or the vicinity thereof, and the peripheral surface of the top cover body 31 and the inner surface of the hard laminate material 2b are bonded together. The layer 26b (that is, the bonding layer 26b in the bonding region Rc) is thermally welded. Similarly, the heater block is pressed from above and below to the bottom end of the exterior material 2 or in the vicinity thereof, and the peripheral surface of the bottom cover 4 and the bonding layer 26b on the inner surface of the hard laminate material 2b are thermally welded. You may do it.

(Resin injection process)
Next, a molten resin is filled between the bottom side end face of the battery element 1 and the bottom cover 4 through a through hole (not shown) and solidified. Thereby, the bottom cover 4 is bonded to the end surface of the battery element 1. The resin to be filled is not particularly limited as long as it has a low viscosity state at the time of casting. For example, polyamide hot melt, polyolefin hot melt, nylon, polypropylene (PP), polycarbonate (PC) Copolymer synthetic resin (ABS resin) of acrylonitrile, butadiene, styrene, or the like can be used.

Note that a molten resin may also be filled between the top cover 3 and the top side end surface of the battery element 1. In this case, one or more through holes may be provided in the top cover 3 and the molten resin may be injected from the through holes.
The target battery is manufactured through the above steps.

[1.3 Effect]
In the battery according to the first embodiment, the top cover 3 and the bottom cover 4 have a recess on the surface facing the joint L1 of the exterior material 2, and the joint L1 is a position facing the recess 3a and the recess 4a. , Or approximately opposite positions. Thereby, when a heavy load is applied to the battery, the direction of battery folding can be controlled such that the battery is folded with the main surface of the battery including the joint L1 as the inside. Further, the position of the battery fold can be controlled so that the battery folds at the position of the seam L1 or substantially at the seam L1. Therefore, it is possible to suppress the exterior material 2 from being bent and generating a sharp portion, and the sharp portion from being stuck into the battery element 1. That is, the occurrence of a short circuit of the battery can be suppressed and the safety of the battery can be improved.

  When one end or both ends of the pair of sides 23b and 24b included in the joint L1 of the exterior material 1 have a shape without corners, even when a large load is applied to the battery and the battery is broken The one or both ends of the sides 23b and 24b can be prevented from piercing the battery element 1. Similarly, when one end or both ends of the pair of sides 23a and 24a included in the joint L2 of the exterior material 1 have a shape without corners, the piercing can be similarly suppressed.

  Under the joints L1 and L2 of the exterior material 2, a soft laminate material 2a that constitutes the protruding surface 2S of the accommodating portion 25 is provided. Therefore, when the battery is folded with the main surface of the battery including the joints L1 and L2 of the exterior material 2 as the inner side, the short sides 23b and 24b of the hard laminate 2b, the short sides 23a and 24a of the soft laminate 2a, and The battery element 1 can be protected from the corners at both ends.

[1.4 Modification]
In the first embodiment described above, the example in which the cross-sectional shape of the recess 3a when the top cover 3 is cut in a direction perpendicular to the thickness direction of the top cover 3 is a V-shape has been described. The shape is not limited to this example. Examples of cross-sectional shapes other than the V shape include polygonal shapes such as a rectangular shape (see FIG. 10A), trapezoidal shapes (see FIG. 10B), U shapes (see FIG. 10C), and partial circles such as a semicircle. Shapes (see FIG. 10D), partial ellipses such as semi-elliptical shapes, and indefinite shapes. 10A to 10D show an example in which the depth of the recess 3a is not more than half the thickness of the top cover 3, but the depth of the recess 3a is limited to this example. Instead, as shown in FIG. 10E, the depth may be more than half the thickness of the top cover 3. The bottom cover 4 may have a cross-sectional shape other than the V-shape as in the top cover 3 described above. The shape of the recess 3a of the top cover 3 and the recess 4a of the bottom cover 4 may be different.

  As shown in FIG. 10F, the top cover 3 may have a hole 3b instead of the recess 3a. In this case, for example, the hole 3b is provided at a position closer to the long surface S131 than the long surface S132, preferably in the vicinity of the long surface S131. It is preferable that the hole 3b is provided at the center or substantially the center of the long surface S131. The joint L1 of the hard laminate material 2b is preferably provided directly above or almost directly above the hole 3b. Examples of the cross-sectional shape of the hole 3b include, but are not limited to, a circular shape, an elliptical shape, a polygonal shape such as a rectangular shape, an indefinite shape, and the like. Similarly to the top cover 3, the bottom cover 4 may have a hole instead of the recess 4a. The shapes of the holes of the top cover 3 and the bottom cover 4 may be different.

  The top cover 3 may have both the recessed part 3a and the hole 3b. In this case, the hole 3b is provided, for example, at a position directly below or substantially directly below the recess 3a. Similarly to the top cover 3, the bottom cover 4 may have both a recess and a hole. Further, one of the top cover 3 and the bottom cover 4 may have a recess, and the other may have a hole.

<2 Second Embodiment>
[2.1 Electronic equipment configuration]
As illustrated in FIG. 11, an electronic device 400 according to the second embodiment of the present technology includes an electronic circuit 401 of the electronic device main body and a battery 300. Here, a configuration in which electronic device 400 includes one battery 300 will be described as an example, but a configuration in which two or more batteries 300 are provided may be employed. The battery 300 is electrically connected to the electronic circuit 401 via the positive terminal 3h and the negative terminal 3i. For example, the electronic device 400 has a configuration in which the battery 300 is detachable by a user. The configuration of the electronic device 400 is not limited to this, and the battery 300 may be built in the electronic device 400 so that the user cannot remove the battery 300 from the electronic device 400. Good.

  When the battery 300 is charged, the positive terminal 3h and the negative terminal 3i of the battery 300 are connected to the positive terminal and the negative terminal of a charger (not shown), respectively. On the other hand, when the battery 300 is discharged (when the electronic apparatus 400 is used), the positive terminal 3h and the negative terminal 3i of the battery 300 are connected to the positive terminal and the negative terminal of the electronic circuit 401, respectively.

  Examples of the electronic device 400 include a notebook personal computer, a tablet computer, a mobile phone (for example, a smartphone), a portable information terminal (Personal Digital Assistants: PDA), an imaging device (for example, a digital still camera, a digital video camera, etc.), Audio equipment (for example, portable audio player), game equipment, cordless phone, e-book, electronic dictionary, radio, headphones, navigation system, electric tool, electric shaver, refrigerator, air conditioner, TV, stereo, water heater, microwave oven, Examples include, but are not limited to, a dishwasher, a washing machine, a dryer, a lighting device, a toy, a medical device, and a robot.

(Electronic circuit)
The electronic circuit 401 includes, for example, a CPU, a peripheral logic unit, an interface unit, a storage unit, and the like, and controls the entire electronic device 400.

(battery)
The battery 300 is a battery according to the above-described first embodiment or a modification thereof. The battery 300 includes a protection circuit 301. This protection circuit 301 is a protection circuit provided on the circuit board 32 in the first embodiment.

[2.2 Effects]
The electronic apparatus 400 includes the battery according to the above-described first embodiment or a modification thereof as the battery 300. Thereby, even when the electronic device 400 is damaged and the battery is broken, it is possible to prevent the battery from being short-circuited. Therefore, the safety of the electronic device 400 can be improved.

  Hereinafter, the present technology will be specifically described by way of examples. However, the present technology is not limited only to these examples.

(Example)
(Battery element manufacturing process)
First, for example, a positive electrode and a negative electrode each having a gel electrolyte layer formed on both sides, and a separator were sequentially laminated in the order of the negative electrode, the separator, the positive electrode, and the separator to form a laminate. Next, this laminate was wound around a flat core and wound many times in the longitudinal direction to produce a wound battery element having a flat shape.

(Battery element exterior process)
First, as a soft laminate material, a rectangular soft aluminum laminate film (hereinafter referred to as “soft Al laminate”) having a laminated structure in which a PP layer (adhesive layer), a soft aluminum layer (metal layer), and a nylon layer (surface protective layer) are sequentially laminated. "Film"). Next, the accommodating part was formed in the soft Al laminate film by deep drawing. Under the present circumstances, the accommodating part was formed in the position which shifted | deviated slightly to one short side side with respect to the center position of a soft Al laminated film. Next, the battery element was accommodated in the accommodating part formed in the soft Al laminate film.

  Next, as a hard laminate material, a rectangular hard aluminum laminate film (hereinafter “hard Al”) having a laminated structure in which a polypropylene layer (adhesive layer), a hard aluminum layer (metal layer), and a nylon layer (surface protective layer) are sequentially laminated. "Laminate film") was prepared. Next, the hard Al laminate film was superposed on the soft Al laminate film at a position shifted in the longitudinal direction thereof. Thereby, the bonding area | region where only a soft Al laminate film exists is formed in the end of the longitudinal direction of both the laminated Al films, and the bonding area | region where only a hard Al laminate film exists in the other end. Been formed.

  Next, in a reduced pressure atmosphere, the battery element was sealed by thermally welding the periphery of the housing portion. Next, a heat welding sheet having a predetermined shape was provided on the protruding surface on the back side of the bottom surface of the housing portion. Next, both ends of the soft Al laminate film and the hard Al laminate film are folded inward toward the main surface of the battery element covered with the soft Al laminate film, that is, the protruding surface on the back side of the bottom surface of the housing portion, and the both ends are pasted. The polypropylene layers in the combined area were overlapped. Under the present circumstances, the joint of the hard Al laminate film was formed in the center of the main surface of a battery element by opposingly arranging so that the short sides of a hard Al laminate film may touch. In addition, on the inner side of the hard Al laminate film, the joint of the soft Al laminate film is formed at a position slightly deviated from the center of the main surface of the battery element by arranging the short sides of the soft Al laminate film in contact with each other. did.

  Next, the polypropylene layers in the bonding region of the soft Al laminate film and the hard Al laminate film were thermally welded together. At the same time, the nylon layer of the soft Al laminate film constituting the protruding surface on the back side of the bottom surface of the housing portion and the nylon layers at both ends of the folded soft Al laminate film were thermally welded via the heat welding sheet. Thereby, the soft Al laminate film and the hard Al laminate film are fixed in a closed state so as to wrap the accommodating portion in which the battery element is accommodated, and have an aluminum laminate film exterior material (hereinafter referred to as “the bottom side opening”). "Al film exterior material") was formed.

(Top cover mating process)
Next, the positive electrode lead and the negative electrode lead were attached to the circuit board via the positive electrode tab and the negative electrode tab, respectively, by ultrasonic welding. Next, a top cover body in which a groove having a V-shaped cross section is provided in the center of the long surface is prepared, and the circuit board, the positive electrode tab, and the negative electrode tab are accommodated in the accommodating portion of the top cover body. The holder was fitted. Thereby, the top cover was formed.

  Next, the top cover was fitted into the top-side opening of the Al film exterior material so that the seam of the hard Al laminate film was opposed to the groove having a V-shaped cross section while appropriately folding back the positive electrode lead and the negative electrode lead.

(Bottom cover fitting process)
Next, a bottom cover having a V-shaped groove in the center of the long surface is prepared, and the bottom cover is covered with an Al film so that the seam of the hard Al laminate film faces the V-shaped groove. It was fitted into the bottom opening of the material.

(Thermal welding process)
Next, the heater block was pressed from above and below against the top end of the Al film exterior material, and the peripheral surface of the top cover main body and the PP layer on the inner surface of the hard Al laminate film were thermally welded.

(Resin injection process)
Next, molten resin was filled between the battery element and the bottom cover through the through hole of the bottom cover and solidified. Thereby, the bottom cover 4 was adhere | attached on the bottom side end surface of the battery element. The target battery was obtained through the above steps.

(Comparative example)
A top cover and a bottom cover were prepared in which a groove having a V-shaped cross section was provided at the center of the long surface opposite to the example . Of the two main surfaces of the battery, the top cover and the bottom cover are respectively placed on the top side of the Al film exterior material such that a groove having a V-shaped cross section is formed on the main surface opposite to the side where the joint is formed. Fit into the opening and bottom opening. Except for this, a battery was obtained in the same manner as in the example.

(Vertical crush test)
A longitudinal crush test was performed by applying a force from both sides of the battery of the example and comparative example obtained as described above toward the center. The results are shown in Table 1.

The result of the vertical crushing test of the battery pack of an Example and a comparative example is shown.

Table 1 shows the following.
Since the top cover has a groove in the center of the long surface facing the joint of the exterior material, the direction of battery folding can be controlled so that the battery can be folded with the main surface of the battery including the joint as the inside. .
The top cover has a groove in the center of the long surface opposite to the long surface facing the joint of the exterior material so that the battery can be folded with the main surface opposite to the main surface of the battery including the joint as the inside. In addition, the direction of battery folding can be controlled.
Since the top cover has a groove in the center of the long surface facing the joint of the exterior material and the joint has a joint at a position where the exterior material faces the groove, occurrence of a short circuit can be suppressed.

  As mentioned above, although embodiment of this art, its modification, and an example were explained concretely, this art is not limited to the above-mentioned embodiment, its modification, and an example. Various modifications based on technical ideas are possible.

  For example, the configurations, methods, processes, shapes, materials, numerical values, and the like given in the above-described embodiment and its modified examples and examples are merely examples, and different configurations, methods, processes, and shapes are necessary as necessary. , Materials and numerical values may be used.

  In addition, the above-described embodiment and its modified examples, and the configurations, methods, processes, shapes, materials, numerical values, and the like of the examples can be combined with each other without departing from the gist of the present technology.

  Further, in the above-described embodiment and its modified examples and examples, the example in which the present technology is applied to the battery having the winding structure has been described, but the structure of the battery is not limited to this, and the positive electrode The present technology can also be applied to a battery having a structure in which the negative electrode is folded or stacked.

  Further, in the above-described embodiment and its modified examples and examples, the case where the battery element is a lithium ion secondary battery has been described as an example. However, the battery element is not limited to this example. The present technology can also be applied to secondary batteries other than secondary batteries, or primary batteries.

  Further, in the above-described embodiment and its modified examples and examples, the battery and the battery element have been described as having a flat shape. However, the shape of the battery and the battery element is not limited to the flat shape, and is rectangular. The present technology can also be applied to a battery having a shape.

  Further, in the above-described embodiment and its modified examples and examples, the present invention is applied to a battery including a non-aqueous electrolyte solution as an electrolyte and a polymer compound serving as a holding body that holds the non-aqueous electrolyte solution. Although the example to which the technology is applied has been described, the electrolyte is not limited to this example. For example, the present technology can also be applied to a battery including an electrolyte such as a non-aqueous electrolyte as an electrolyte, or a battery including a solid electrolyte containing an electrolyte salt as an electrolyte.

  Further, in the above-described embodiment and its modified examples and examples, the configuration has been described in which the exterior material has the top side opening and the bottom side opening, and the top cover and the bottom cover are fitted to the openings, respectively. The configuration of the battery is not limited to this. For example, the present technology can also be applied to a battery having a configuration in which an exterior material has only one of a top-side opening and a bottom-side opening and a cover is fitted to the opening.

  Further, in the above-described embodiment and its modified examples, and examples, the battery is described as including two exterior materials, a soft laminate material (first exterior material) and a hard laminate material (second exterior material). However, the configuration of the battery is not limited to this. For example, the present technology can be applied to a battery including only one exterior material or a battery including three or more exterior materials. In addition, when a battery is provided with three or more exterior materials and three or more joints of exterior materials are provided, it opposes the joint of the hardest exterior material among three or more exterior materials. It is preferable to provide a concave portion at a position or a substantially opposite position.

The present technology can also employ the following configurations.
(1)
A battery element;
While packaging the battery element, an exterior material having an opening;
A cover body provided in the opening,
The cover body has a recess on the surface facing the joint of the exterior material,
The joint is a battery at a position facing or substantially facing the recess.
(2)
A battery element;
While housing the battery element, an exterior material having a first opening and a second opening,
A first cover body provided in the first opening;
A second cover body provided in the second opening;
With
At least one of the first cover body and the second cover body has a recess on the surface facing the joint of the exterior material,
The joint is a battery at a position facing or substantially facing the recess.
(3)
The said recessed part is a battery as described in (1) or (2) provided in the center of the said surface.
(4)
The battery according to any one of (1) to (3), wherein one end or both ends of a pair of sides included in the joint of the exterior material have a shape without corners.
(5)
The exterior material is
A first exterior material;
A second exterior material superimposed on the first exterior material,
The battery according to any one of (1) to (4), wherein both ends of the second exterior material are joined together on the main surface of the battery element to form the joint.
(6)
The exterior material is
A first exterior material;
A second exterior material that is shifted and superimposed on the first exterior material,
The shifted portions of the first exterior material and the second exterior material are overlapped on the main surface of the battery element, and the seam of the first exterior material and the seam of the second exterior material are overlapped. Is configured,
The battery according to any one of (1) to (5), wherein the joint of the exterior material is a joint of the second exterior material.
(7)
The battery according to (5) or (6), wherein the second exterior material is harder than the first exterior material.
(8)
The battery according to any one of (1) to (7), wherein the exterior material is a laminate film.
(9)
The battery element has a flat shape or a square shape,
The battery according to any one of (1) to (8), wherein the joint is provided on a main surface of the battery element.
(10)
(1) to the battery according to any one of (9),
An electronic device that receives power from the battery.

DESCRIPTION OF SYMBOLS 1 Battery element 2 Exterior material 2a Soft laminating material 2b Hard laminating material 3 Top cover 3a, 4a Recessed part 3b Hole part 4 Bottom cover 5a Positive electrode lead 5b Negative electrode lead 6 Label L1, L2 Joint S13, S23 Circumferential surface S131, S132, S231 , S232 long surface S133, S134, S233, S234 short surface

Claims (9)

A battery element having a flat shape or a square shape ;
While containing the battery element, an exterior material having an opening,
A cover body provided in the opening,
The exterior material includes a metal layer,
The cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided at the center of the surface,
The said seam is a battery which is provided on the main surface of the said battery element, and exists in the position which opposes the said recessed part, or a substantially opposition position. A battery element having a flat shape or a square shape ;
While housing the battery element, an exterior material having a first opening and a second opening,
A first cover body provided in the first opening;
A second cover body provided in the second opening;
With
The exterior material includes a metal layer,
At least one of the first cover body and the second cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided at the center of the surface,
The said seam is a battery which is provided on the main surface of the said battery element, and exists in the position which opposes the said recessed part, or a substantially opposition position. The battery according to claim 1 or 2 , wherein one end or both ends of a set of sides included in the joint of the exterior material have a shape without corners. The exterior material is
A first exterior material;
A second exterior material superimposed on the first exterior material,
The battery according to any one of claims 1 to 3, wherein both ends of the second exterior material are joined together on a main surface of the battery element to form the joint. The exterior material is
A first exterior material;
A second exterior material that is shifted and superimposed on the first exterior material,
The shifted portions of the first exterior material and the second exterior material are overlapped on the main surface of the battery element, and the seam of the first exterior material and the seam of the second exterior material are overlapped. Is configured,
The battery according to any one of claims 1 to 3, wherein the joint of the exterior material is a joint of the second exterior material. The battery according to claim 4 or 5, wherein the second exterior material is harder than the first exterior material. The battery according to claim 1, wherein the exterior material is a laminate film. A battery element having a flat shape or a square shape ;
While containing the battery element, an exterior material having an opening,
A cover body provided in the opening,
The exterior material includes a metal layer,
The cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided at the center of the surface,
The seam includes a battery provided on the main surface of the battery element and located at a position facing or substantially facing the recess.
An electronic device that receives power from the battery. A battery element having a flat shape or a square shape ;
While housing the battery element, an exterior material having a first opening and a second opening,
A first cover body provided in the first opening;
A second cover body provided in the second opening;
With
The exterior material includes a metal layer,
At least one of the first cover body and the second cover body has a recess on the surface facing the joint of the exterior material,
The recess is provided at the center of the surface,
The seam includes a battery provided on the main surface of the battery element and located at a position facing or substantially facing the recess.
An electronic device that receives power from the battery.

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