JP6064926B2 - Separator and battery - Google Patents

Description

  The present invention relates to a separator and a battery, and more particularly to a microporous separator and a battery including a positive electrode, a negative electrode, an electrolyte, and a separator.

  Due to the remarkable development of portable electronic technology in recent years, mobile phones and notebook computers are recognized as basic technologies that support an advanced information society. Research and development related to the enhancement of the functions of these devices has been energetically advanced, and it has been an issue that the increase in power consumption due to the enhancement of functions shortens the driving time.

  In order to ensure a driving time of a certain level or higher, it is essential to increase the energy density of a secondary battery used as a driving power source. For example, a high-functional secondary battery represented by a lithium ion secondary battery or the like Further increase in energy density is expected.

  In a conventional lithium ion secondary battery, a lithium cobaltate is used for the positive electrode and a carbon material is used for the negative electrode, and the operating voltage has been used in the range of 4.2V to 2.5V. In the unit cell, the terminal voltage can be increased to 4.2 V largely due to excellent electrochemical stability of a non-aqueous electrolyte material or a separator.

  By the way, the positive electrode active material such as lithium cobaltate used in the conventional lithium ion secondary battery operating at a maximum of 4.2 V only uses a capacity of about 60% of its theoretical capacity. In principle, it is possible to utilize the remaining capacity by increasing the charging voltage. In fact, for example, as disclosed in Patent Document 1, it is known that high energy density is manifested by setting the voltage during charging to 4.25 V or more.

International Publication No. WO03 / 019713A1 Pamphlet

  However, the polyolefin microporous membrane used in the nonaqueous electrolyte secondary battery is in physical contact with the positive electrode as a result of an oxidizing atmosphere particularly in the vicinity of the positive electrode surface when the charging voltage is set to 4.25 V or higher. There is a problem that the nonaqueous electrolyte material and the separator are easily subjected to oxidative decomposition, resulting in an increase in internal resistance and a decrease in battery characteristics. Moreover, even if it is a charging voltage lower than 4.25V, it is calculated | required to suppress deterioration of a battery characteristic by using the separator which has oxidation resistance.

  Accordingly, an object of the present invention is to provide a separator and a battery that can suppress deterioration of battery characteristics.

In order to solve the above-described problems, a first invention is a separator used for a battery including a positive electrode and a negative electrode including at least one of lithium (Li), silicon (Si), and tin-cobalt alloy (SnCo). In addition, a resin layer made of a porous matrix resin containing an inorganic substance is provided on at least one main surface of the substrate layer made of a microporous film of the separator, and the inorganic substance is made of metal oxide, metal nitride, or semiconductor. And at least one of an oxide and a semiconductor nitride, and the matrix resin is polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polytetrafluoroethylene, and vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene. It is at least one selected from the group consisting of copolymers and has an air permeability of 30 sec / 00cc~520sec / 100cc range der of is, piercing strength, a separator is in the range of 100Gf～210gf.

A second invention is a battery in which a positive electrode and a negative electrode are arranged to face each other via a separator, and the negative electrode includes at least one of lithium (Li), silicon (Si), and tin-cobalt alloy (SnCo), A resin layer made of a porous matrix resin containing an inorganic substance is provided on at least one main surface of a base material layer made of a microporous film of a separator, and the inorganic substance contains a metal oxide, a metal nitride, a semiconductor oxide, and The semiconductor resin is at least one of nitrides of the semiconductor, and the matrix resin is polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polytetrafluoroethylene, and vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer. The separator has an air permeability of 30 sec / 100. C～520sec / Ri range der of 100 cc, a piercing strength of the separator, a battery is in the range of 100Gf～210gf.

  In the first invention and the second invention, the separator has a structure in which a resin layer having an inorganic substance is provided on at least one main surface of the base material layer. Deterioration can be suppressed.

  According to this invention, there is an effect that the durability of the separator can be improved and the deterioration of the battery characteristics can be suppressed.

It is a schematic sectional drawing of the nonaqueous electrolyte battery by 1st Embodiment of this invention. FIG. 2 is an enlarged sectional view of a part of a wound electrode body shown in FIG. 1. It is an expanded sectional view of an example of a separator. It is an expanded sectional view of other examples of a separator. It is the schematic which shows the structure of the nonaqueous electrolyte battery by 2nd Embodiment of this invention. FIG. 6 is an enlarged cross-sectional view of a part of the battery element shown in FIG. 5.

(1) First Embodiment (1-1) Configuration of Nonaqueous Electrolyte Battery Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional structure of a secondary battery using a microporous membrane according to the first embodiment of the present invention.

  In this secondary battery, the open circuit voltage in a fully charged state (hereinafter, appropriately referred to as a fully charged state) per pair of positive and negative electrodes is within a range of 4.2 V to 4.6 V, for example, or 4.25 V to 4 Within the range of .6V. This secondary battery is a so-called cylindrical type, and is a wound electrode in which a strip-shaped positive electrode 2 and a strip-shaped negative electrode 3 are wound via a separator 4 inside a substantially hollow cylindrical battery can 1. It has a body 20.

  The battery can 1 is made of, for example, iron (Fe) plated with nickel (Ni), and has one end closed and the other end open. Inside the battery can 1, a pair of insulating plates 5 and 6 are arranged perpendicular to the winding peripheral surface so as to sandwich the winding electrode body 20.

  At the open end of the battery can 1, a battery lid 7, a safety valve mechanism 8 and a thermal resistance element (PTC element) 9 provided inside the battery lid 7 are interposed via a gasket 10. It is attached by caulking and the inside of the battery can 1 is sealed. The battery lid 7 is made of, for example, the same material as the battery can 1. The safety valve mechanism 8 is electrically connected to the battery lid 7 via a heat sensitive resistance element 9, and the disk plate 11 is reversed when the internal pressure of the battery becomes a certain level or more due to internal short circuit or external heating. Thus, the electrical connection between the battery lid 7 and the wound electrode body 20 is cut off. The heat-sensitive resistor element 9 limits the current by increasing the resistance value when the temperature rises, and prevents abnormal heat generation due to a large current. The gasket 10 is made of, for example, an insulating material, and asphalt is applied to the surface.

  The wound electrode body 20 is wound around, for example, the center pin 12. A positive electrode lead 13 made of aluminum or the like is connected to the positive electrode 2 of the wound electrode body 20, and a negative electrode lead 14 made of nickel or the like is connected to the negative electrode 3. The positive electrode lead 13 is electrically connected to the battery lid 7 by welding to the safety valve mechanism 8, and the negative electrode lead 14 is welded and electrically connected to the battery can 1.

[Positive electrode]
FIG. 2 shows an enlarged part of the spirally wound electrode body 20 shown in FIG. As shown in FIG. 2, the positive electrode 2 includes, for example, a positive electrode current collector 2A having a pair of opposed surfaces, and a positive electrode mixture layer 2B provided on both surfaces of the positive electrode current collector 2A. In addition, you may make it have the area | region where the positive mix layer 2B was provided only in the single side | surface of 2 A of positive electrode collectors. The positive electrode current collector 2A is made of, for example, a metal foil such as an aluminum (Al) foil. The positive electrode mixture layer 2B includes, for example, a positive electrode active material, and may include a conductive agent such as graphite and a binder such as polyvinylidene fluoride as necessary.

As the positive electrode active material, a lithium-containing compound, for example, lithium oxide, lithium sulfide, or an intercalation compound containing lithium is suitable, and two or more of these may be used in combination. In particular, in order to increase the energy density, it is preferable that a lithium composite oxide mainly composed of LixMO2 is included as the positive electrode active material. M is preferably one or more transition metals, specifically, cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), aluminum (Al), vanadium (V) and titanium ( At least one of the group consisting of Ti) is preferred. In addition, x varies depending on the charge / discharge state of the battery, and is usually a value in the range of 0.05 ≦ x ≦ 1.10. Specific examples of such lithium composite oxide include, for example, Li _a CoO ₂ (a≈1), Li _b NiO ₂ (b≈1), or Li _c Ni _d Co _1-d O ₂ (c≈1, 0 <d <1). Examples of the lithium composite oxide include Li _e Mn ₂ O ₄ (e≈1) having a spinel structure or Li _f FePO ₄ (f≈1) having an olivine structure.

  More specifically, a lithium transition metal composite oxide having a composition represented by (Chemical Formula 1) to (Chemical Formula 5) described below can be used.

(Chemical formula 1)
_{Li [Li x Mn (1-} xyz) Ni y M 'z] O (2-a) F b
(Wherein M ′ is cobalt (Co), manganese (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), tungsten (W), and x represents at least one element. 0 <x ≦ 0.2, y is 0.3 ≦ y ≦ 0.8, z is 0 ≦ z ≦ 0.5, a is −0.1 ≦ a ≦ 0.2, b is 0 ≦ b ≦ 0 The value is within the range of .1.)

(Chemical formula 2)
Li _c Ni _(1-d) M '' _d O _(2-e) F _f
(Where M ″ is cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron ( It represents at least one element selected from Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). Is -0.1≤c≤0.1, d is 0.005≤d≤0.5, e is -0.1≤e≤0.2, and f is in the range of 0≤f≤0.1. Value.)

(Chemical formula 3)
Li _c Co _(1-d) M ''' _d O _(2-e) F _f
(Where M ′ ″ is nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron It represents at least one element selected from (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). c is −0.1 ≦ c ≦ 0.1, d is 0 ≦ d ≦ 0.5, e is −0.1 ≦ e ≦ 0.2, and f is a value within the range of 0 ≦ f ≦ 0.1. .)

(Chemical formula 4)
Li _s Mn _2-t M '''' _t O _u F _v
(Where M ″ ″ is cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), Represents at least one element selected from iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W) S is a value within a range of s ≧ 0.9, t is 0.005 ≦ t ≦ 0.6, u is 3.7 ≦ u ≦ 4.1, and v is a value within a range of 0 ≦ v ≦ 0.1. )

  Moreover, the lithium transition metal composite phosphate which has a composition represented by (Formula 5) described below can also be used.

(Chemical formula 5)
LiM '''''PO ₄
(Where M ′ ″ ″ 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), zirconium (Zr) Represents one or more elements.)

[Negative electrode]
As shown in FIG. 2, the negative electrode 3 includes, for example, a negative electrode current collector 3A having a pair of opposed surfaces, and a negative electrode mixture layer 3B provided on both surfaces of the negative electrode current collector 3A. In addition, you may make it have the area | region in which the negative mix layer 3B was provided only in the single side | surface of 3 A of negative electrode collectors. The negative electrode current collector 3A is made of a metal foil such as a copper (Cu) foil. The negative electrode mixture layer 3B includes, for example, a negative electrode active material, and may include a binder such as polyvinylidene fluoride as necessary.

The negative electrode active material includes a negative electrode material capable of inserting and extracting lithium (hereinafter, appropriately referred to as a negative electrode material capable of inserting and extracting lithium). Examples of negative electrode materials capable of inserting and extracting lithium include carbon materials, metal compounds, oxides, sulfides, lithium nitrides such as LiN ₃ , lithium metals, metals that form alloys with lithium, or polymer materials. Is mentioned.

  Examples of the carbon material include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, glassy carbons, organic polymer compound fired bodies, carbon fibers, and activated carbon. Among these, examples of coke include pitch coke, needle coke, and petroleum coke. An organic polymer compound fired body is a carbonized material obtained by firing a polymer material such as a phenol resin or a 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.

  Among such negative electrode materials capable of inserting and extracting lithium, those having a charge / discharge potential relatively close to lithium metal are preferable. This is because the lower the charge / discharge potential of the negative electrode 3, the easier the battery has a higher energy density. Among these, a carbon material is preferable because a change in crystal structure that occurs during charge / discharge is very small, a high charge / 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. Moreover, non-graphitizable carbon is preferable because excellent cycle characteristics can be obtained.

  Examples of the negative electrode material capable of inserting and extracting lithium include lithium metal alone, a metal element or a metalloid element capable of forming an alloy with lithium, an alloy, or a compound. These are preferable because a high energy density can be obtained, and in particular, when used together with a carbon material, a high energy density can be obtained and excellent cycle characteristics can be obtained, and therefore, it is more preferable. Note that in this specification, alloys include those composed of one or more metal elements and one or more metalloid elements in addition to those composed of two or more metal elements. The structures include solid solutions, eutectics (eutectic mixtures), intermetallic compounds, or those in which two or more of them coexist.

Examples of such metal elements or metalloid elements include tin (Sn), lead (Pb), aluminum, indium (In), silicon (Si), zinc (Zn), antimony (Sb), bismuth (Bi), and cadmium. (Cd), magnesium (Mg), boron (B), gallium (Ga), germanium (Ge), arsenic (As), silver (Ag), zirconium (Zr), yttrium (Y) or hafnium (Hf). It is done. These alloys or compounds, for example, those represented by the chemical formula Ma _s Mb _t Li _u or a chemical formula Ma _p Mc _q Md _r,. In these chemical formulas, Ma represents at least one of a metal element and a metalloid element capable of forming an alloy with lithium, Mb represents at least one of a metal element and a metalloid element other than lithium and Ma, Mc represents at least one of nonmetallic elements, and Md represents at least one of metallic elements and metalloid elements other than Ma. The values of s, t, u, p, q, and r are s> 0, t ≧ 0, u ≧ 0, p> 0, q> 0, and r ≧ 0, respectively.

  Among these, a simple substance, alloy or compound of a group 4B metal element or metalloid element in the short-period type periodic table is preferable, and silicon or tin, or an alloy or compound thereof is particularly preferable. These may be crystalline or amorphous.

In addition, inorganic compounds that do not contain lithium, such as MnO ₂ , V ₂ O ₅ , V ₆ O ₁₃ , NiS, and MoS, can also be used for either the positive or negative electrode.

[Electrolyte]
As the electrolytic solution, a nonaqueous electrolytic solution in which an electrolyte salt is dissolved in a nonaqueous solvent can be used. As the non-aqueous solvent, for example, it is preferable to contain at least one of ethylene carbonate and propylene carbonate. This is because the cycle characteristics can be improved. In particular, it is preferable to mix and contain ethylene carbonate and propylene carbonate because cycle characteristics can be further improved. The nonaqueous solvent preferably contains at least one of chain carbonates such as diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, or methyl propyl carbonate. This is because the cycle characteristics can be further improved.

  The non-aqueous solvent preferably further contains at least one of 2,4-difluoroanisole and vinylene carbonate. This is because 2,4-difluoroanisole can improve discharge capacity, and vinylene carbonate can further improve cycle characteristics. In particular, it is more preferable that they are mixed and contained because both the discharge capacity and the cycle characteristics can be improved.

  Non-aqueous solvents further include butylene carbonate, γ-butyrolactone, γ-valerolactone, those in which part or all of the hydrogen groups of these compounds are substituted with fluorine groups, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyl Tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, methyl acetate, methyl propionate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropironitrile, N, N-dimethylformamide N-methylpyrrolidinone, N-methyloxazolidinone, N, N-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, dimethyl sulfoxide or trimethyl phosphate may be included. Yes.

  Depending on the electrode to be combined, the reversibility of the electrode reaction may be improved by using a material in which part or all of the hydrogen atoms of the substance contained in the non-aqueous solvent group are substituted with fluorine atoms. Therefore, these substances can be used as appropriate.

Examples of the lithium salt that is an electrolyte salt include LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiClO ₄ , LiB (C ₆ H ₅ ) ₄ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) _2. , LiC (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , LiSiF ₆ , LiCl, LiBF ₂ (ox), LiBOB, or LiBr are suitable, and one or more of these are used in combination. be able to. Among them, LiPF ₆ is preferable because it can obtain high ion conductivity and can improve cycle characteristics.

[Separator]
Hereinafter, an example of the structure of the separator 4 and other examples will be described with reference to FIGS. 3 and 4. FIG. 3 is an enlarged cross-sectional view showing an example of the structure of the separator 4. As shown in FIG. 3, the separator 4 has a structure in which a resin layer 4a is provided on one main surface of the base material layer 4b. As the material for the base material layer 4b, it is possible to use those used in conventional batteries. Among these, it is particularly preferable to use a polyolefin microporous film that is excellent in short-circuit prevention effect and that can improve battery safety by a shutdown effect.

  Specifically, for example, a microporous film made of polyethylene or polypropylene resin is preferable. In addition, although the base material layer 4b shown in FIG. 3 has a single layer structure, the base material layer 4b may have a multilayer structure. More specifically, for example, a microporous film having a three-layer structure in which a polypropylene (PP) layer, a polyethylene (PE) layer, and a PP layer are sequentially laminated is used as the base material layer 4b having a multilayer structure. be able to.

  The resin layer 4a is a highly porous matrix resin layer on which an inorganic substance is supported. By having the resin layer 4a in which an inorganic substance is supported on the matrix resin, oxidation resistance can be obtained and deterioration of the separator 4 can be suppressed.

  More specifically, as the matrix resin, for example, polyvinylidene fluoride (PVdF), hexafluoropropylene (HFP), polytetrafluoroethylene (PTFE) or the like can be used, and these copolymers are used. It is also possible.

As the inorganic substance, a metal, a semiconductor, or an oxide or nitride thereof can be given. Specific examples of the metal include aluminum (Al) and titanium (Ti). Examples of the semiconductor include silicon (Si) and boron (B). Examples of the oxide or nitride include alumina (Al ₂ O ₃ ), boron nitride (BN), aluminum nitride (AlN), titanium dioxide (TiO ₂ ), and silicon dioxide (SiO ₂ ). Moreover, as an inorganic substance, a thing with no electrical conductivity, excellent availability, and a large heat capacity is preferable. This is because a large heat capacity is useful as a heat sink when heat is generated and functions to suppress thermal runaway. Examples of such inorganic substances include alumina (Al ₂ O ₃ ), boron nitride (BN), aluminum nitride (AlN), titanium dioxide (TiO ₂ ), and silicon dioxide (SiO ₂ ).

  The particle size of the inorganic substance is preferably in the range of 1 nm to 10 μm. If it is smaller than 1 nm, it is difficult to obtain, and even if it can be obtained, it is not worth the cost. If it is larger than 10 μm, the distance between the electrodes becomes large, and a sufficient amount of active material cannot be obtained in a limited space, resulting in a low battery capacity.

  As a method for forming the resin layer 4a, for example, a slurry made of a matrix resin, a solvent and an inorganic substance is applied on the base material layer 4b, and the mixture is passed through a poor solvent of the matrix resin and a parent solvent bath of the solvent to cause phase separation. Then, it can be formed by drying.

  The puncture strength of the separator 4 is preferably in the range of 100 gf to 1000 gf. This is because if the piercing strength is low, a short circuit may occur, and if the piercing strength is high, the ionic conductivity decreases.

  In addition, the air permeability of the separator is preferably in the range of 30 sec / 100 cc to 1000 sec / 100 cc. This is because when the air permeability is low, a short circuit may occur, and when the air permeability is high, the ion conductivity decreases.

  FIG. 4 is an enlarged sectional view showing another example of the structure of the separator 4. As shown in FIG. 4, the separator 4 has a structure in which a resin layer 4c and a resin layer 4e are provided on both surfaces of a base material layer 4b. Since the structure other than the separator 4 is the same as the above-described example, detailed description thereof is omitted.

(1-2) Nonaqueous Electrolyte Battery Manufacturing Method Next, a nonaqueous electrolyte battery manufacturing method according to the first embodiment of the present invention will be described. Hereinafter, a nonaqueous electrolyte battery manufacturing method will be described by taking a cylindrical nonaqueous electrolyte battery as an example.

  The positive electrode 2 is produced as described below. First, for example, a positive electrode active material, a conductive agent, and a binder are mixed to prepare a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone to form a positive electrode mixture. Use slurry.

  Next, after applying this positive electrode mixture slurry to the positive electrode current collector 2A and drying the solvent, the positive electrode mixture layer 2B is formed by compression molding with a roll press or the like, and the positive electrode 2 is produced.

  The negative electrode 3 is produced as described below. First, for example, a negative electrode active material and a binder are mixed to prepare a negative electrode mixture, and the negative electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone to obtain a negative electrode mixture slurry.

  Next, after applying this negative electrode mixture slurry to the negative electrode current collector 3A and drying the solvent, the negative electrode mixture layer 3B is formed by compression molding using a roll press or the like, and the negative electrode 3 is produced.

  Next, the positive electrode lead 13 is attached to the positive electrode current collector 2A by welding or the like, and the negative electrode lead 14 is attached to the negative electrode current collector 3A by welding or the like. Next, the positive electrode 2 and the negative electrode 3 are wound through the separator 4, and the tip of the positive electrode lead 13 is welded to the safety valve mechanism 8, and the tip of the negative electrode lead 14 is welded to the battery can 1. The rotated positive electrode 2 and negative electrode 3 are sandwiched between a pair of insulating plates 5 and 6 and stored in the battery can 1.

  Next, an electrolytic solution is injected into the battery can 1 and the separator 4 is impregnated with the electrolytic solution. Next, the battery lid 7, the safety valve mechanism 8, and the heat sensitive resistance element 9 are fixed to the opening end of the battery can 1 by caulking through the gasket 10. As described above, the nonaqueous electrolyte battery according to the first embodiment of the present invention is manufactured.

  In the nonaqueous electrolyte battery according to the first embodiment of the present invention, when charged, for example, lithium ions are released from the positive electrode 2 and inserted in the negative electrode 3 through the electrolytic solution. When discharging is performed, for example, lithium ions are detached from the negative electrode 3 and inserted into the positive electrode 2 through the electrolytic solution. In the first embodiment, the separator 4 has excellent oxidation resistance, and a high energy density non-aqueous electrolyte secondary battery can be provided.

(2) Second Embodiment (2-1) Configuration of Nonaqueous Electrolyte Battery FIG. 3 shows the structure of a nonaqueous electrolyte battery according to the second embodiment of the present invention. As shown in FIG. 3, the nonaqueous electrolyte battery is sealed by housing the battery element 30 in an exterior material 37 made of a moisture-proof laminate film and welding the periphery of the battery element 30. The battery element 30 is provided with a positive electrode lead 32 and a negative electrode lead 33, and these leads are sandwiched between outer packaging materials 37 and pulled out to the outside. A resin piece 34 and a resin piece 35 are coated on both surfaces of the positive electrode lead 32 and the negative electrode lead 33 in order to improve the adhesion to the exterior material 37.

[Exterior material]
The packaging material 37 has, for example, a stacked structure in which an adhesive layer, a metal layer, and a surface protective layer are sequentially stacked. The adhesive layer is made of a polymer film. Examples of the material constituting the polymer film include polypropylene (PP), polyethylene (PE), unstretched polypropylene (CPP), linear low density polyethylene (LLDPE), and low density. A polyethylene (LDPE) is mentioned. The metal layer is made of a metal foil, and an example of a material constituting the metal foil is aluminum (Al). Moreover, it is also possible to use metals other than aluminum as a material which comprises metal foil. Examples of the material constituting the surface protective layer include nylon (Ny) and polyethylene terephthalate (PET). The surface on the adhesive layer side is a storage surface on the side where the battery element 30 is stored.

[Battery element]
For example, as shown in FIG. 6, the battery element 30 includes a strip-like negative electrode 43 provided with a gel electrolyte layer 45 on both sides, a separator 44, and a strip-like positive electrode 42 provided with a gel electrolyte layer 45 on both sides. The battery element 30 is a wound type battery element 30 that is formed by laminating the separator 44 and wound in the longitudinal direction.

  The positive electrode 42 includes a strip-like positive electrode current collector 42A and a positive electrode active material layer 42B formed on both surfaces of the positive electrode current collector 42A. The positive electrode current collector 42A is a metal foil made of, for example, aluminum (Al).

  One end of the positive electrode 42 in the longitudinal direction is provided with a positive electrode lead 32 connected by, for example, spot welding or ultrasonic welding. As a material of the positive electrode lead 32, for example, a metal such as aluminum can be used.

  The negative electrode 43 includes a strip-shaped negative electrode current collector 43A and a negative electrode active material layer 43B formed on both surfaces of the negative electrode current collector 43A. The negative electrode current collector 43A is made of, for example, a metal foil such as a copper (Cu) foil, a nickel foil, or a stainless steel foil.

  Similarly to the positive electrode 42, the negative electrode lead 33 connected by, for example, spot welding or ultrasonic welding is also provided at one end portion of the negative electrode 43 in the longitudinal direction. As a material of the negative electrode lead 33, for example, copper (Cu), nickel (Ni) or the like can be used.

  Since things other than the gel electrolyte layer 45 are the same as those in the first embodiment, the gel electrolyte layer 45 will be described below.

  The gel electrolyte layer 45 includes an electrolytic solution and a polymer compound serving as a holding body that holds the electrolytic solution, and has a so-called gel shape. The gel electrolyte layer 45 is preferable because it can obtain high ionic conductivity and prevent battery leakage. The configuration of the electrolytic solution (that is, the liquid solvent, the electrolyte salt, and the additive) is the same as that in the first embodiment.

  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, from the viewpoint of electrochemical stability, polyacrylonitrile, polyvinylidene fluoride, polyhexafluoropropylene, or polyethylene oxide is preferable.

(2-2) Method for Manufacturing Nonaqueous Electrolyte Battery Next, a method for manufacturing a nonaqueous electrolyte battery according to the second embodiment of the present invention will be described. First, a precursor solution containing a solvent, an electrolyte salt, a polymer compound, and a mixed solvent is applied to each of the positive electrode 42 and the negative electrode 43, and the mixed solvent is volatilized to form the gel electrolyte layer 45. The positive electrode lead 32 is attached to the end of the positive electrode current collector 42A in advance by welding, and the negative electrode lead 33 is attached to the end of the negative electrode current collector 43A in advance by welding.

  Next, the positive electrode 42 and the negative electrode 43 on which the gel electrolyte layer 45 is formed are laminated via a separator 44 to form a laminated body, and then the laminated body is wound in the longitudinal direction thereof to form a wound battery element 30. Form.

  Next, a recess 36 is formed by deep-drawing an exterior material 37 made of a laminate film, the battery element 30 is inserted into the recess 36, and an unprocessed portion of the exterior material 37 is folded back to the upper portion of the recess 36. The outer peripheral part of is thermally welded and sealed. As described above, the nonaqueous electrolyte battery according to the second embodiment of the present invention is manufactured.

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

Table 1 shows Example 22, Example 23, Reference Example 1 to Reference Example 21, Reference Example 24 to Reference Example 37, and Comparative Example 1 to Comparative Example 10. Hereinafter, with reference to Table 1, Example 22, Example 23, Reference Example 1 to Reference Example 21, Reference Example 24 to Reference Example 37, and Comparative Example 1 to Comparative Example 10 will be described.

  The positive electrode was produced as follows. A positive electrode mixture was prepared by mixing 98 wt% of lithium cobaltate (LiCoO2), 0.8 wt% of amorphous carbon powder (Ketjen Black) and 1.2 wt% of polyvinylidene fluoride (PVdF) as a positive electrode active material. . After this positive electrode mixture was dispersed in N-methyl-2-pyrrolidone (NMP) to produce a positive electrode mixture slurry, this positive electrode mixture slurry was uniformly applied to both surfaces of a positive electrode current collector made of a strip-shaped aluminum foil. . The obtained coated product was dried with hot air, and then compression molded with a roll press to form a positive electrode mixture layer.

  The negative electrode was produced as follows. A negative electrode mixture was prepared by mixing 90 wt% of graphite powder and 10 wt% of PVdF. After this negative electrode mixture was dispersed in N-methyl-2-pyrrolidone to produce a negative electrode mixture slurry, the negative electrode mixture slurry was uniformly applied to both sides of a negative electrode current collector made of a strip-shaped copper foil. Was subjected to hot press molding to form a negative electrode mixture layer.

  The separator was produced as follows. First, N-methyl-2pyrrolidone was added at a mass ratio of 10:90 and sufficiently dissolved in a poly (vinylidene fluoride) resin (average molecular weight of 150,000) to prepare a 10 wt% solution of PVdF in N-methyl-2pyrrolidone.

Next, as an inorganic substance, Al ₂ O ₃ (alumina) fine powder having an average particle diameter of 250 nm was added to the solution so as to be twice the amount of PVdF, and stirred well to prepare a coating slurry. Next, the prepared slurry was coated on a 16 μm-thick polyethylene (PE) microporous membrane as a substrate layer with a tabletop coater, then phase-separated in a water bath, dried with hot air, and alumina. A microporous membrane having a PVdF microporous layer having a thickness of 4 μm carrying slag was obtained.

Here, the air permeability and puncture strength described below were measured for the produced separator.
Air permeability measurement The air permeability was measured according to JIS P8117 using a Gurley densometer (manufactured by Toyo Seiki).
Measurement of Puncture Strength Using a handy compression tester (KES-G5 manufactured by Kato Tech Co., Ltd.), the maximum load when a needle having a diameter of φ1.0 mm was punctured at 2 mm / sec was defined as the puncture strength.

As a result of the above measurement, the air permeability (JIS P8117) of the separator of Reference Example 1 was 550 sec / 100 cc. The puncture strength was 400 gf, and the separator was excellent in ion permeability.

  Next, the separator, the positive electrode, and the negative electrode were laminated in the order of the negative electrode, the separator, the positive electrode, and the separator, and wound many times in a spiral shape, thereby producing a jelly roll type wound electrode body.

  After producing the wound electrode body, a pair of insulating plates are arranged perpendicularly to the peripheral surface of the wound electrode body so as to sandwich the wound electrode body, and in order to collect the positive electrode, it is made of aluminum. One end of the positive electrode lead was led out from the positive electrode current collector, and the other end was electrically connected to the battery lid via a disk plate. Further, in order to collect the negative electrode current, one end of a nickel negative electrode lead was led out from the negative electrode current collector, and the other end was welded to the battery can. In addition, the wound electrode body was housed in the battery can, and the electrolyte was injected into the battery can by a reduced pressure method.

For the electrolytic solution, a mixed solvent in which 35 wt% of ethylene carbonate, 63 wt% of dimethyl carbonate and 2 wt% of vinylene carbonate were mixed was prepared. Further, a solution in which LiPF ₆ was dissolved in this mixed solvent so that the molar concentration was 1.5 mol / kg was used. Finally, the battery can was caulked through a gasket coated with asphalt, and the safety valve mechanism, the heat sensitive resistance element, and the battery lid were hermetically sealed. Thus, a cylindrical nonaqueous electrolyte secondary battery of Reference Example 1 was produced.

Next, the secondary battery of Reference Example 1 was subjected to the float test described below.
Float test The battery was charged so that the open circuit voltage in a fully charged state was 4.2 V or higher, and the fluctuation of the charging current value in a high temperature overcharged state was examined. Hereinafter, this charging current value fluctuation is referred to as a float characteristic. The float characteristic was performed by a constant current constant voltage method of 1000 h in a high temperature bath maintained at 60 ° C. Specifically, after starting constant current charging at 500 mA, switching to constant voltage charging was performed when the voltage between terminals increased to a predetermined voltage. The time until the rise of the current after constant voltage charging was measured and defined as the float limit time.

In Reference Example 1, the battery was charged so that the open circuit voltage in a fully charged state was 4.2 V, and a float test was performed. Moreover, after charging so that the open circuit voltage in a fully charged state was 4.2 V, discharging was performed at a constant current of 540 mA (0.2 C) until 3.0 V, and the capacity was measured.

As shown in Table 1, in Reference Example 1, the float limit time exceeded 1000 hours and exhibited good float characteristics. The capacity at full charge was 2500 mAh.

<Reference Example 2 to Reference Example 9>
< Reference Example 2>
A secondary battery of Reference Example 2 was produced in the same manner as Reference Example 1. Charging was performed such that the open circuit voltage in the fully charged state was 4.25V. Next, capacity measurement and a float test were performed.

< Reference Example 3>
A secondary battery of Reference Example 3 was produced in the same manner as Reference Example 1. Charging was performed such that the open circuit voltage in the fully charged state was 4.30V. Next, capacity measurement and a float test were performed.

< Reference Example 4>
A secondary battery of Reference Example 4 was produced in the same manner as Reference Example 1. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 5>
A secondary battery of Reference Example 5 was produced in the same manner as Reference Example 1. Charging was performed so that the open circuit voltage in the fully charged state was 4.40V. Next, capacity measurement and a float test were performed.

< Reference Example 6>
A secondary battery of Reference Example 6 was produced in the same manner as Reference Example 1. Charging was performed so that the open circuit voltage in the fully charged state was 4.45V. Next, capacity measurement and a float test were performed.

< Reference Example 7>
A secondary battery of Reference Example 7 was produced in the same manner as Reference Example 1. Charging was performed such that the open circuit voltage in the fully charged state was 4.50V. Next, capacity measurement and a float test were performed.

< Reference Example 8>
A secondary battery of Reference Example 8 was produced in the same manner as Reference Example 1. Charging was performed so that the open circuit voltage in a fully charged state was 4.55V. Next, capacity measurement and a float test were performed.

< Reference Example 9>
A secondary battery of Reference Example 9 was produced in the same manner as Reference Example 1. Charging was performed so that the open circuit voltage in the fully charged state was 4.60V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Reference Example 2 to Reference Example 9, all exhibited good floating properties.

< Reference Example 10 to Reference Example 14>
< Reference Example 10>
A secondary battery of Reference Example 10 was produced in the same manner as Reference Example 1 except that alumina fine powder having an average particle diameter of 7 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 11>
A secondary battery of Reference Example 11 was produced in the same manner as Reference Example 1 except that alumina fine powder having an average particle diameter of 16 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 12>
A secondary battery of Reference Example 12 was produced in the same manner as Reference Example 1 except that alumina fine powder having an average particle diameter of 40 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 13>
A secondary battery of Reference Example 13 was produced in the same manner as Reference Example 1 except that alumina fine powder having an average particle diameter of 140 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 14>
A secondary battery of Reference Example 14 was produced in the same manner as Reference Example 1 except that alumina fine powder having an average particle diameter of 380 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Reference Example 10 to Reference Example 14, all exhibited good floating properties.

< Reference Example 15 to Reference Example 18>
< Reference Example 15>
A secondary battery of Reference Example 15 was fabricated in the same manner as Reference Example 1 except that boron nitride (BN) having an average particle diameter of 140 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 16>
A secondary battery of Reference Example 16 was fabricated in the same manner as Reference Example 1, except that aluminum nitride (AlN) having an average particle size of 140 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 17>
A secondary battery of Reference Example 17 was fabricated in the same manner as Reference Example 1, except that titanium dioxide (TiO ₂ ) having an average particle diameter of 140 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 18>
A secondary battery of Reference Example 18 was fabricated in the same manner as Reference Example 1, except that silicon dioxide (SiO ₂ ) having an average particle diameter of 140 nm was used as the inorganic substance. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Reference Example 15 to Reference Example 18, all exhibited good floating properties.

< Reference Example 19 to Reference Example 21>
< Reference Example 19>
A secondary battery of Reference Example 19 was produced in the same manner as Reference Example 1, except that lithium (Li) was used for the negative electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 20>
A secondary battery of Reference Example 20 was produced in the same manner as Reference Example 1 except that silicon (Si) was used for the negative electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 21>
A secondary battery of Reference Example 21 was produced in the same manner as Reference Example 1 except that a tin-cobalt alloy (Sn—Co) was used for the negative electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Reference Example 19 to Reference Example 21, all exhibited good floating properties.

<Example 22 , Example 23, Reference Example 24, Reference Example 25>
<Example 22>
A secondary battery of Example 22 was made in the same manner as in Reference Example 1, except that the thickness of the PE microporous film as the base material layer was changed to 5 μm. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

<Example 23>
A secondary battery of Example 23 was made in the same manner as Reference Example 1, except that the thickness of the PE microporous film as the base material layer was 7 μm. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 24>
A secondary battery of Reference Example 24 was produced in the same manner as Reference Example 1 except that the thickness of the PE microporous film as the base material layer was 9 μm. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 25>
A secondary battery of Reference Example 25 was produced in the same manner as Reference Example 1 except that the thickness of the PE microporous film as the base material layer was 20 μm. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Example 22 , Example 23, Reference Example 24, and Reference Example 25, all exhibited good float characteristics.

< Reference Example 26>
Instead of PE microporous membrane as a substrate layer, a surface layer of polypropylene having a thickness of 16 [mu] m (PP), except that the inner layer PE, using a three-layer, microporous membrane of the surface layer PP is in the same manner as in Reference Example 1, Reference Example 26 secondary batteries were produced. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, all of Reference Examples 26 exhibited good float characteristics.

< Reference Example 27 to Reference Example 29>
< Reference Example 27>
A secondary battery of Reference Example 27 was made in the same manner as Reference Example 1, except that polytetrafluoroethylene (PTFE) was used as the matrix resin. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 28>
A secondary battery of Reference Example 28 was produced in the same manner as Reference Example 1, except that polyvinylidene fluoride-hexafluoropropylene (PVdF-HEP) copolymer was used as the matrix resin. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 29>
A secondary battery of Reference Example 29 was produced in the same manner as Reference Example 1, except that a polyvinylidene fluoride-hexafluoropropylene-polytetrafluoroethylene (PVdF-HEP-PTFE) copolymer was used as the matrix resin. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Reference Example 27 to Reference Example 29, all exhibited good floating properties.

< Reference Example 30 to Reference Example 32>
< Reference Example 30>
A secondary battery of Reference Example 30 was produced in the same manner as Reference Example 1 except that PVdF having an average molecular weight of 50,000 was used. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 31>
A secondary battery of Reference Example 31 was produced in the same manner as Reference Example 1, except that PVdF having an average molecular weight of 300,000 was used. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 32>
A secondary battery of Reference Example 32 was produced in the same manner as Reference Example 1 except that PVdF having an average molecular weight of 1,000,000 was used. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, Reference Example 30 to Reference Example 32 all showed good float characteristics.

< Reference Example 33 to Reference Example 35>
< Reference Example 33>
A secondary battery of Reference Example 33 was made in the same manner as Reference Example 1 except that LiCoO ₂ / LiNiCoMnO ₂ = 8/2 (mass ratio) was used for the positive electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 34>
A secondary battery of Reference Example 34 was made in the same manner as Reference Example 1 except that LiNiMnO ₄ was used for the positive electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 35>
A secondary battery of Reference Example 35 was produced in the same manner as Reference Example 1, except that lithium cobalt phosphate (LiCoPO ₄ ) was used for the positive electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, all of Reference Example 33 to Reference Example 35 exhibited good float characteristics.

< Reference Example 36 to Reference Example 37>
< Reference Example 36>
A secondary battery of Reference Example 36 was made in the same manner as Reference Example 1, except that the thickness of the resin layer was 1 μm. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

< Reference Example 37>
A secondary battery of Reference Example 37 was made in the same manner as Reference Example 1, except that the thickness of the resin layer was 10 μm. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

As shown in Table 1, in Reference Example 36 to Reference Example 37, but the float time decreases as the thickness of the resin layer is thin, all exhibited good floating properties.

<Comparative Example 1>
A slurry prepared in the same manner as in Reference Example 1 was applied on a microporous PE film having a thickness of 16 μm using a desktop coater, dried in hot air without being phase-separated in a water bath, and a PVdF layer supporting alumina was formed. A PE microporous membrane was prepared.

  In Comparative Example 1, the thickness of the separator was 20 μm, but the PVdF layer did not have porosity, no air permeability, and the air permeability could not be measured. That is, there was no microporosity and a membrane with poor ion permeability and poor ion permeability, and did not function as a battery.

<Comparative example 2>
A secondary battery of Comparative Example 2 was produced in the same manner as Reference Example 1, except that the PE fine multilayer film having a thickness of 20 μm was used without applying the slurry of Reference Example 1. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

  As shown in Table 1, a current rise was observed after 150 hours, and it was found that a minute short circuit occurred.

<Comparative Example 3 to Comparative Example 5>
<Comparative Example 3>
A secondary battery of Comparative Example 3 was fabricated in the same manner as Comparative Example 2, except that lithium (Li) was used for the negative electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

<Comparative example 4>
A secondary battery of Comparative Example 4 was produced in the same manner as Comparative Example 2 except that silicon (Si) was used for the negative electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

<Comparative Example 5>
A secondary battery of Comparative Example 5 was fabricated in the same manner as Comparative Example 2, except that tin-cobalt alloy (Sn—Co) was used for the negative electrode. Charging was performed such that the open circuit voltage in the fully charged state was 4.35V. Next, capacity measurement and a float test were performed.

  As shown in Table 1, in Comparative Example 3, it was found that a current rise was observed after 150 hours, and a micro short circuit occurred. In Comparative Example 4, it was found that a current rise was observed after 100 hours, and a micro short circuit occurred. In Comparative Example 5, it was found that a current rise was observed after 100 hours, and a micro short circuit occurred.

<Comparative Example 6>
A secondary battery of Comparative Example 6 was produced in the same manner as Comparative Example 2. Charging was performed so that the open circuit voltage in the fully charged state was 4.20V. Next, capacity measurement and a float test were performed.

  As shown in Table 1, in Comparative Example 6, it was found that a current rise was observed after 400 hours, and a micro short circuit occurred.

<Comparative Example 7>
A secondary battery of Comparative Example 7 was produced in the same manner as Comparative Example 2. Charging was performed such that the open circuit voltage in the fully charged state was 4.25V. Next, capacity measurement and a float test were performed.

  In Comparative Example 7, it was found that a current rise was observed after 400 hours, and a micro short circuit occurred.

<Comparative Example 8 to Comparative Example 10>
<Comparative Example 8>
A secondary battery of Comparative Example 8 was produced in the same manner as Comparative Example 3. Charging was performed such that the open circuit voltage in the fully charged state was 4.25V. Next, capacity measurement and a float test were performed.

<Comparative Example 9>
A secondary battery of Comparative Example 9 was produced in the same manner as Comparative Example 4. Charging was performed such that the open circuit voltage in the fully charged state was 4.25V. Next, capacity measurement and a float test were performed.

<Comparative Example 10>
A secondary battery of Comparative Example 10 was produced in the same manner as Comparative Example 5. Charging was performed such that the open circuit voltage in the fully charged state was 4.25V. Next, capacity measurement and a float test were performed.

  As shown in Table 1, in Comparative Example 8, it was found that a current rise was observed after 110 hours, and a micro short circuit occurred. In Comparative Example 9, it was found that a current rise was observed after 95 hours, and a minute short circuit occurred. In Comparative Example 10, a current rise was observed after 104 hours, and it was found that a minute short circuit occurred.

  The present invention is not limited to the above-described embodiments of the present invention, and various modifications and applications are possible without departing from the spirit of the present invention. The present invention is not limited to the above-described embodiments of the present invention, and various modifications and applications are possible without departing from the spirit of the present invention. For example, the shape is not particularly limited. It may be a cylindrical shape, a square shape, a coin shape, a button shape, or the like.

  In the first embodiment, the non-aqueous electrolyte battery having an electrolyte as an electrolyte has been described. In the second embodiment, the non-aqueous electrolyte battery having a gel electrolyte as an electrolyte has been described. However, the present invention is not limited thereto. is not.

  For example, as the electrolyte, in addition to the above-described ones, a polymer solid electrolyte using an ion conductive polymer or an inorganic solid electrolyte using an ion conductive inorganic material can be used. It may be used in combination with the electrolyte. Examples of the polymer compound that can be used for the polymer solid electrolyte include polyether, polyester, polyphosphazene, and polysiloxane. Examples of the inorganic solid electrolyte include ion conductive ceramics, ion conductive crystals, and ion conductive glass.

DESCRIPTION OF SYMBOLS 1 ... Battery can 2 ... Positive electrode 2A ... Positive electrode collector 2B ... Positive electrode mixture layer 3A ... Negative electrode collector 3B ... Negative electrode mixture layer 3 ... Negative electrode 4. ··· Separator 4a, 4c, 4e ··· Resin layer 4b, 4d · · · Base layer 5, 6 · · · Insulating plate 7 · · · Battery cover 8 · · · Safety valve mechanism 9 · · · Thermal resistance element DESCRIPTION OF SYMBOLS 10 ... Gasket 11 ... Disc board 12 ... Center pin 13 ... Positive electrode lead 14 ... Negative electrode lead 20 ... Winding electrode body 30 ... Battery element 32 ... Positive electrode lead 33 ... Negative electrode lead 34, 35 ... Resin piece 35 ... Negative electrode lead 36 ... Recess 37 ... Exterior material 42 ... Positive electrode 42A ... Positive electrode current collector 42B ... Positive electrode mixture Layer 43 ... Negative electrode 43A ... Negative electrode current collector 43B ... Negative electrode mixture layer 44 ... Separator 45 ... Gel electrolyte layer

Claims (22)

A separator used for a battery having a positive electrode and a negative electrode including at least one of lithium (Li), silicon (Si), and tin-cobalt alloy (SnCo),
A resin layer made of a porous matrix resin containing an inorganic substance is provided on at least one main surface of the base material layer made of the microporous membrane of the separator,
The inorganic material is at least one of a metal oxide, a metal nitride, a semiconductor oxide, and a semiconductor nitride,
The matrix resin is at least one selected from the group consisting of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polytetrafluoroethylene, and vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer. And
Air permeability, Ri range in Der of 30sec / 100cc~520sec / 100cc,
A separator having a puncture strength in the range of 100 gf to 210 gf .   2. The separator according to claim 1, wherein the inorganic substance has a particle size in a range of 250 nm to 10 μm. According to claim 1 or 2, the air permeability is in the range of 290sec / 100cc~520sec / 100cc separators.   The separator according to any one of claims 1 to 3, wherein the inorganic substance is at least one of alumina, boron nitride, aluminum nitride, titanium dioxide, and silicon dioxide.   5. The separator according to claim 1, wherein the resin layer is a layer in which the inorganic substance is supported on the porous matrix resin. 6. The separator according to any one of claims 1 to 5 , wherein the base material layer has a thickness of 5 to 20 µm. A battery in which a positive electrode and a negative electrode are arranged to face each other with a separator interposed therebetween,
The negative electrode includes at least one of lithium (Li), silicon (Si), and tin-cobalt alloy (SnCo),
A resin layer made of a porous matrix resin containing an inorganic substance is provided on at least one main surface of the base material layer made of the microporous membrane of the separator,
The inorganic material is at least one of a metal oxide, a metal nitride, a semiconductor oxide, and a semiconductor nitride,
The matrix resin is at least one selected from the group consisting of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polytetrafluoroethylene, and vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer. And
Air permeability of the separator is, Ri range der of 30sec / 100cc~520sec / 100cc,
A battery in which the puncture strength of the separator is in the range of 100 gf to 210 gf . The battery according to claim 7, wherein the inorganic substance has a particle size in a range of 250 nm to 10 μm. According to claim 7 or 8, the air permeability is in the range of 290sec / 100cc~520sec / 100cc battery. The battery according to any one of claims 7 to 9 , wherein the inorganic substance is at least one of alumina, boron nitride, aluminum nitride, titanium dioxide, and silicon dioxide. The battery according to any one of claims 7 to 10 , wherein the resin layer is a layer in which the inorganic substance is supported on the porous matrix resin. The battery according to any one of claims 7 to 11 , wherein the base material layer has a thickness of 5 to 20 µm. The positive electrode according to any one of claims 7 to 12 , wherein the positive electrode is a lithium-cobalt composite oxide, a lithium- nickel-cobalt-manganese composite oxide, a lithium-nickel-manganese composite oxide, and a lithium-cobalt composite phosphoric acid. A battery comprising at least one of the salts. The battery according to any one of claims 7 to 13 , wherein the negative electrode further includes a carbon material. The battery according to any one of claims 7 to 14 , wherein a gel electrolyte layer is provided between at least one of the positive electrode and the separator and between the negative electrode and the separator. The battery according to claim 15, wherein the gel electrolyte layer includes an electrolytic solution and a polymer compound that holds the electrolytic solution. The polymer compound according to claim 16, wherein the polymer compound is polyacrylonitrile, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, or polyphosphazene. Batteries that are polysiloxane, polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene or polycarbonate. The battery according to any one of claims 7 to 14 , wherein a polymer solid electrolyte or an inorganic solid electrolyte is provided between at least one of the positive electrode and the separator and between the negative electrode and the separator. According to any one of claims 7 to 18, housed in the outer package made of a laminate film battery. 20. The battery according to claim 19, wherein the exterior material has a laminated structure in which an adhesive layer, a metal layer, and a surface protective layer are sequentially laminated. The open circuit voltage in a fully charged state per pair of the positive electrode and the negative electrode is in the range of 4.2 V to 4.6 V according to any one of claims 7 to 20 ,
A battery having a float limit time of 500 hours or more when a float test is performed. The battery according to any one of claims 7 to 20 , wherein an open circuit voltage in a fully charged state per pair of the positive electrode and the negative electrode is in a range of 4.25V to 4.6V.

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