JP2007157459A - Nonaqueous electrolytic solution battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize high energy density and excellent discharge characteristics of a nonaqueous electrolyte solution battery with a maximum charging voltage of 4.25 V or more and 6.9 V or less, through restraint of damage of a material of a separator as well as of degradation of floating characteristics. <P>SOLUTION: A wound-around electrode body 20 having a cathode 2 and an anode 3 of a strip shape wound through a separator is provided inside a battery can 1. A fluororesin layer 2c is provided at an interface between the cathode 2 and the separator 4. The fluororesin resin layer 2c is there for lowering chemical reaction between the cathode 2 and the separator 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a nonaqueous electrolyte battery, and more particularly to a nonaqueous electrolyte battery including a positive electrode, a negative electrode, a nonaqueous 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

  On the other hand, it has been reported that when the charging voltage is increased, the battery characteristics are significantly deteriorated. For example, as described in Non-Patent Document 2, when a lithium ion secondary battery in which a charging voltage is set to about 4.4 V is evaluated, the basic characteristic deterioration of the battery is particularly remarkable in a temperature range higher than room temperature. There is a problem.

J. R. Dahn et al., Electrochimica Acta, 49, 1079-1090, (2004).

  Conventionally, for example, as described in Patent Document 3, such deterioration phenomenon is caused by distortion or fatigue generated in the crystal structure due to an increase in the amount of insertion / extraction of lithium ions, or oxidation of the positive electrode itself. There have been reports of chemical changes in electrolyte materials due to increased properties.

JP 2004-55539 A

For example, as described in Non-Patent Document 4 and Non-Patent Document 5, for example, a lithium-containing composite oxide having a layered structure is made of an oxide such as ZnO or Al ₂ O ₃ against such a deterioration phenomenon. There have been reports mainly focusing on the improvement of the positive electrode active material, such as the proposal of a coated compound.

J. Prakash et al., Journal of the Electrochemical Society, 150 (7), A970-A972 (2003). B. Park et al., Journal of the Electrochemical Society, 149 (2), A127-A132 (2002).

  However, although the improvement by these structures shows a certain level of effect, further improvement is particularly required for the float characteristics at high temperatures. Accordingly, the inventors of the present application conducted extensive studies on improvement of the float characteristics at high temperatures, and as described below, the deterioration reaction of the separator is remarkably reduced in the present battery system characterized by a particularly high charging voltage. Was determined to be a factor.

  The inventors of the present application selected lithium ion secondary batteries as investigation targets as models of non-aqueous electrolyte batteries having a maximum charging voltage of 4.25 V or more, and inspected their storage deterioration at high temperatures in detail as follows. Succeeded in obtaining new and novel findings.

  That is, in the conventional lithium ion secondary battery having a maximum charging voltage of 4.2 V, the oxidative decomposition reaction of the separator that comes into contact with the positive electrode having an increased oxidizing power is very slow because the apparent reaction rate itself is very low. It was experimentally found that a system in which decomposition of the molecular structure hardly occurs during storage under the condition was established, and as a result, characteristic deterioration after storage was difficult to occur. On the other hand, in a non-aqueous electrolyte battery having a maximum charging voltage of 4.25 V or more, the oxidation power of the positive electrode exceeds the oxidation resistance limit of the polyolefin material, which is the main component of the separator, resulting in significant damage to the separator material and float characteristics. Has newly found that is deteriorated. This deterioration behavior is a novel finding that is different from the deterioration behavior caused by the decomposition reaction of the electrolyte material in the vicinity of the positive electrode which has been reported in the past. It has been found that by improving this deterioration behavior, it is possible to significantly improve the battery characteristics.

  Therefore, an object of the present invention is to suppress the separator material from being significantly damaged and to prevent the float characteristics from deteriorating in a non-aqueous electrolyte battery having a maximum charging voltage of 4.25V to 6.0V. An object of the present invention is to provide a non-aqueous electrolyte battery that can realize a high energy density and excellent discharge characteristics.

In order to solve the above-described problems, the present invention provides:
A non-aqueous electrolyte battery having a positive electrode, a negative electrode, a non-aqueous electrolyte, and a separator, and an open circuit voltage in a fully charged state per pair of the positive electrode and the negative electrode is in the range of 4.25V to 6.00V. And
A nonaqueous electrolyte battery characterized in that a porous layer made of a fluorine-containing polymer is provided between a separator and a positive electrode.

  According to the present invention, in a nonaqueous electrolyte battery having an open circuit voltage of 4.25 V or more and 6.00 V or less in a fully charged state per pair of positive electrode and negative electrode, a porous material composed of a fluorine-containing polymer between the positive electrode and the separator. A quality layer is provided. This effectively reduces the chemical reaction between the positive electrode and the separator material, thereby suppressing significant damage to the separator material resulting from the positive electrode oxidizing power exceeding the oxidation resistance limit of the polyolefin material, which is the main component of the separator. The float characteristics can be prevented from deteriorating.

  According to this invention, in a non-aqueous electrolyte battery having an open circuit voltage in a fully charged state per pair of positive electrode and negative electrode of 4.25 V or more and 6.00 V or less, it is possible to suppress the material of the separator from being significantly damaged, and to have float characteristics. By suppressing the deterioration, it is possible to realize a high energy density and excellent discharge characteristics.

(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 per pair of positive and negative electrodes is greater than 4.20V and less than or equal to 6.00V, greater than 4.20V and less than or equal to 4.65V, or greater than or equal to 4.25V and greater than or equal to 6.25V. 00V or less, or 4.25V to 4.65V.

  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. In addition, a fluororesin layer 2 c is provided at the interface between the positive electrode 2 and the separator 4. The fluororesin layer 2 c is for reducing the chemical reaction between the positive electrode 2 and the separator 4.

  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, for example, aluminum is connected to the positive electrode 2 of the spirally wound electrode body 20, and a negative electrode lead 14 made of, for example, nickel is connected to the negative electrode 3. The positive electrode lead 13 is electrically connected to the battery cover 7 by being welded 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 such as 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 to include a lithium composite oxide mainly composed of Li _x MO ₂ as a 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.

  For example, a lithium transition metal composite oxide having a composition represented by (Chemical Formula 1) to (Chemical Formula 2) described below as a general formula can be used.

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

(Chemical formula 2)
Li _a M2 _b PO ₄
(M2 represents at least one element selected from Group 2 to Group 15. a and b are values within the range of 0 ≦ a ≦ 2.0 and 0.5 ≦ b ≦ 2.0. )

[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 a metal element or metalloid element include tin (Sn), lead (Pb), aluminum (Al), indium (In), silicon (Si), zinc (Zn), antimony (Sb), and bismuth (Bi). ), Cadmium (Cd), magnesium (Mg), boron (B), gallium (Ga), germanium (Ge), arsenic (As), silver (Ag), zirconium (Zr), yttrium (Y) or hafnium (Hf) ). 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]
Below, the separator material which can be utilized for 1st Embodiment is demonstrated. As a separator material, 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. For example, a microporous film made of polyethylene or polypropylene resin is preferable.

  Further, as the separator material, it is more preferable to use a laminate or mixture of polyethylene having a lower shutdown temperature and polypropylene having excellent oxidation resistance from the viewpoint of achieving both shutdown performance and float characteristics.

  A porous fluororesin layer 2 c is provided at the interface between the separator 4 and the positive electrode 2. As the material of the fluororesin layer 2c, a material having a basic skeleton of polytetrafluoroethylene, more preferably, polyvinylidene fluoride or polyhexafluoropropylene can be used. Furthermore, these copolymers can also be used. In addition, perfluoroalkoxyalkanes (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resins), ethylene-tetrafluoroethylene copolymers, perfluoroethylene-propene copolymers, ethylene-chlorotrifluoroethylene copolymers, etc. can be used. .

  It is necessary to carefully arrange the fluororesin layer 2c so as not to hinder the movement of ions serving as electrode reactive species. As a method of actually interposing, it can carry in advance on the positive electrode surface or the separator surface. Furthermore, in the system employing the wound electrode body 20 as in the embodiment of the present invention, it is possible to spray directly on the interface between the positive electrode 2 and the separator 4 during winding.

The amount of the intervening fluororesin layer 2c is defined by the weight per unit area. For example, it is preferable to intervene so that it becomes 0.1 mg / cm ² or more and 10 mg / cm ² or less. This is because if it is less than 0.1 mg / cm ² , it is difficult to exert a protective effect against the oxidative decomposition reaction. This is because if it is greater than 10 mg / cm ² , the decrease in energy density becomes prominent due to the redundancy of the ion conduction path length due to the increase in the distance between the electrodes, which is inappropriate.

  As a method of providing the fluororesin layer 2c on the electrode surface or the separator surface, a method of drying after spraying a fluororesin suspension on the surface to be deposited, a method of drying after applying a fluororesin solution with a bar coater or the like Etc. can be cited as representative examples. Thus, the method of providing the fluororesin layer 2c is not limited, but the above-described suspension spraying method easily exhibits a porous structure of the fluororesin layer 2c. This is a more preferable method.

(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 1-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 1-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 having the fluorine-containing resin layer 2c supported on the surface in advance and the negative electrode 3 are wound through the separator 4, 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 also wound. The part is welded to the battery can 1, and the wound positive electrode 2 and negative electrode 3 are sandwiched between a pair of insulating plates 5 and 6 and stored inside 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.

(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. 4, the battery element 30 includes a strip-shaped negative electrode 43 provided with a gel electrolyte layer 45 on both sides, a separator 44, and a strip-shaped 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. Further, a fluororesin layer 42 c is provided between the separator 44 and the positive electrode 42. The fluororesin layer 42 c is for reducing the chemical reaction between the positive electrode 42 and the separator 44. In the second embodiment, an example in which the fluororesin layer 42c is provided at the interface between the separator 44 and the gel electrolyte layer 45 will be described, but the present invention is not limited to this. For example, it is possible to provide a fluororesin layer 42 c at the interface between the positive electrode 42 and the gel electrolyte layer 45. Further, for example, a fluororesin layer 42 c can be provided at the interface between the separator 44 and the gel electrolyte layer 45 and at the interface between the positive electrode 42 and the gel electrolyte layer 45. In addition to the above-described embodiment, for example, the battery element 30 can be configured only with a non-aqueous electrolyte without using a gel electrolyte. Furthermore, an embodiment such as a square battery in which similar battery elements are housed in a metal case instead of a laminate film is also possible.

  The positive electrode 42 includes a strip-shaped positive electrode current collector 42A and a positive electrode mixture 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 mixture layer 43B formed on both surfaces of the negative electrode current collector 43A. As 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. In addition, 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 by welding.

  Next, after the positive electrode 42 and the negative electrode 43 on which the gel electrolyte layer 45 is formed are laminated through a separator 44 on which a fluororesin layer 42c is supported in advance, the laminate is wound in the longitudinal direction. Turn to form a wound battery element 30.

  Next, a recess 36 is formed by deep drawing the 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.

  In the first and second embodiments of the present invention, the non-aqueous electrolyte battery is characterized in that the open circuit voltage in a fully charged state is 4.25 V or more and 6.0 V or less, particularly at high temperatures. It is possible to effectively reduce the chemical reaction between the positive electrode material and the separator material to be converted, and it is possible to realize a higher energy density and excellent discharge characteristics.

  A specific embodiment of the present invention will be described in detail with reference to FIGS. Note that the present invention is not limited to these examples.

  Table 1 shows the materials of the positive electrode 2 and the negative electrode 3 used in Examples 1 to 35 and Comparative Examples 1 to 9, the charging voltage, the coating material, the coating weight, the material and thickness of the separator 4, and the rated energy density. , Discharge capacity ratio, continuous charge time. Hereinafter, Examples 1 to 35 and Comparative Examples 1 to 9 will be described with reference to Table 1.

<Example 1>
The positive electrode 2 was produced as follows. Lithium cobaltate (shown as positive electrode II in Table 1) and lithium carbonate powder were mixed at a ratio of 95% by mass and 1% by mass, respectively, and then this mixture was mixed with amorphous carbon powder (Ketjen). Black) and polyvinylidene fluoride were mixed at a ratio of 94% by mass, 3% by mass, and 3% by mass, respectively, to prepare a positive electrode mixture. After this positive electrode mixture was dispersed in 1-methyl-2-pyrrolidone to prepare a positive electrode mixture slurry, this positive electrode mixture slurry was uniformly applied to both surfaces of a positive electrode current collector 2A made of a strip-shaped aluminum foil having a thickness of 15 μm. did. The obtained coated material was dried with hot air and then compression molded with a roll press to form a positive electrode mixture layer 2B. The total thickness of the positive electrode 2 was set to 135 μm.

As a method of providing a stable layer at the interface between the positive electrode 2 and the separator 4, in Example 1, a polytetrafluoroethylene-containing suspension (PTFE, Daikin Industries) on the positive electrode 2 has a basis weight of 1 mg / cm ^2. After spray coating as described above, the desired positive electrode material was obtained by drying under reduced pressure at 120 ° C. for 24 hours.

The negative electrode 3 was produced as follows. Spherical graphite powder having an average particle diameter of 20 μm and a specific surface area of 0.8 g / cm ³ , polyvinylidene fluoride and carbon fiber (fiber average diameter of 0.1 μm, aspect ratio of 5) are 90% by mass, 8% by mass and 2%, respectively. A negative electrode mixture was prepared by mixing at a mass% ratio. After this negative electrode mixture was dispersed in 1-methyl-2-pyrrolidone to prepare a negative electrode mixture slurry, the negative electrode mixture slurry was uniformly applied to both surfaces of the negative electrode current collector 3A made of a strip-shaped copper foil having a thickness of 12 μm. Furthermore, the negative electrode mixture layer 3B was formed by subjecting this to hot press molding. The total thickness of the negative electrode 3 was set to 140 μm.

  After the positive electrode 2 and the negative electrode 3 were prepared, a microporous film mainly composed of polyethylene having the physical properties shown in Table 1 was used as the separator 4, and the separator 4, the positive electrode 2, and the negative electrode 3 were combined with the negative electrode 3, the separator 4, and the positive electrode. 2 and separator 4 were laminated in this order, and wound many times in a spiral shape to produce a jelly roll-type wound electrode body 20 having an outer diameter of 17.0 mm.

  After producing the wound electrode body 20, a pair of insulating plates 5, 6 are arranged perpendicular to the peripheral surface of the wound electrode body 20 so as to sandwich the wound electrode body 20, and the current collector of the positive electrode 2 is collected. Therefore, one end of the positive electrode lead 13 made of aluminum was led out from the positive electrode current collector 2 </ b> A, and the other end was electrically connected to the battery lid 7 via the disk plate 11. Further, in order to collect the current of the negative electrode 3, one end of the nickel negative electrode lead 14 was led out from the negative electrode current collector 3 </ b> A, and the other end was welded to the battery can 1. In addition, the wound electrode body 20 was housed in the battery can 1 and 4.0 g of the electrolyte solution was injected into the battery can 1 by a reduced pressure method.

For the electrolytic solution, a mixed solvent in which 35% by mass of ethylene carbonate, 63% by mass of dimethyl carbonate and 2% by mass 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 1 was caulked through a gasket 10 coated with asphalt to seal the safety valve mechanism 8, the heat sensitive resistance element 9, and the battery lid 7 in an overlapped state. As described above, the cylindrical secondary battery of Example 1 having a diameter of 18 mm and a height of 50 mm was obtained.

  Next, for the purpose of demonstrating the effect of the invention, as described below, the measurement of the rated energy density, the discharge characteristic test, and the continuous charge test at a high temperature of 60 ° C. were performed as described in Example 1. went.

  Unless otherwise specified, the charge / discharge test was performed under the following conditions. That is, charging was performed by a constant current constant voltage method. Specifically, after starting charging at a constant current of 500 mA, switching to constant voltage charging was performed when the voltage between terminals increased to 4.40 V, respectively. Charging was terminated when 5 hours had elapsed after the start of charging. In this specification, such a state is defined as a fully charged state. Discharging was performed by a constant current method. Specifically, discharge was started at 300 mA until the voltage between the terminals dropped to 2.75V. Such a state is defined as a complete discharge state.

Rated energy density The rated energy density is determined by measuring the discharge capacity at the second charge / discharge operation described above, defining this as the rated capacity, and dividing the product of the discharge voltage and the rated capacity when measuring the rated capacity by the actual battery volume. I estimated it.

Discharge characteristic test In the discharge characteristic test, the discharge capacity ratio is obtained by dividing the discharge capacity obtained when the discharge current is set to a current value equivalent to 2C in the above-described charge / discharge operation by the rated capacity, and the output of the battery. The characteristics were compared.

Continuous charging test In the continuous charging test, a battery in a fully charged state was subjected to constant current and constant voltage charging while maintaining the charging voltage at an environmental temperature of 70 ° C. In this test, immediately after the start of observation, the charging current decreases to maintain the same voltage immediately after the voltage between the terminals of the battery reaches the charging voltage. A tendency for the charging current once decreased to increase again is observed, but this is thought to suggest that some chemical reaction is occurring inside the battery, so it is an index for evaluating the stability of the battery. It becomes. In this specification, the stability of the battery under high temperature was evaluated by measuring the time which reached 20 mA or more after the start of the test.

<Comparative Examples 1 to 2>
<Comparative Example 1>
A secondary battery of Comparative Example 1 was fabricated in the same manner as in Example 1 except that the PTFE layer was not provided. Next, for Comparative Example 1, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, it was confirmed that by providing the PTFE layer at the interface between the positive electrode 2 and the separator 4, it was possible to significantly improve the continuous charge time while maintaining a good energy density and discharge capacity ratio. .

<Comparative example 2>
A secondary battery of Comparative Example 2 was fabricated in the same manner as Comparative Example 1, except that the charging voltage was 4.20V. Next, for Comparative Example 2, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, in Comparative Example 2, a good continuous charge time was observed despite the absence of the PTFE layer.

<Comparative Example 3>
Furthermore, in order to verify the protective effect of the PTFE layer under the condition where the charging voltage is 4.20 V, Comparative Example 3 is the same as Comparative Example 2 except that the PTFE layer is provided at the interface between the positive electrode 2 and the separator 4. A secondary battery was prepared. Next, for Comparative Example 3, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, it was confirmed that the protective effect of the PTFE layer was not recognized under the condition of the charging voltage of 4.20V.

  As described above, the results obtained in Example 1 and Comparative Examples 1 to 3 are based on measures such as providing a PTFE layer in the current lithium ion secondary battery operating at the upper limit charging voltage of 4.20 V. It is suggested that the technology of the present invention is specifically effective in a battery in which the charging voltage exceeds 4.20 V and the oxidizing atmosphere in the vicinity of the positive electrode surface is stronger. It suggests.

<Example 2 to Example 6>
A mixture of a layered lithium-containing composite oxide having a composition shown in Table 1 (shown as positive electrode I in Table 1) and lithium cobaltate (shown as positive electrode II in Table 1) at a ratio shown in Table 1. Except for the mixed point, secondary batteries of Examples 2 to 6 were produced in the same manner as Example 1. The layered lithium-containing composite oxide having the composition shown in Table 1 was prepared as described below.
Preparation of layered lithium-containing composite oxide Using commercially available nickel nitrate, cobalt nitrate, and manganese nitrate as an aqueous solution, mixing them so that the ratios of Ni, Co, and Mn are 0.50, 0.20, and 0.30, respectively. While stirring, aqueous ammonia was added dropwise to obtain a composite hydroxide. This was mixed with lithium hydroxide, calcined at 850 ° C. for 10 hours in an oxygen stream, and then pulverized to obtain the lithium transition metal composite oxide. When the obtained powder was analyzed by atomic absorption analysis, the composition of LiNi _0.50 Co _0.20 Mn _0.30 O ₂ was confirmed. Further, when the particle diameter was measured by a laser diffraction method, the average particle diameter was 13 μm. Moreover, when X-ray diffraction measurement of this powder was performed, the obtained pattern was similar to the pattern of LiNiO ₂ in 09-0063 of ICDD, and formed a layered rock salt structure similar to LiNiO ₂ . Was confirmed. Further, when the powder was observed with a SEM (Scanning Electron Microscope), spherical particles in which primary particles of 0.1 to 5 μm were aggregated were observed.
Next, for Examples 2 to 6, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, the battery characteristics of Examples 2 to 6 were compared with those of Comparative Example 1 and Comparative Example 2, respectively. As a result, all of them had good rated energy density, discharge capacity ratio, and continuous charging. Time was observed.

<Example 7 to Example 8>
In particular, the secondary batteries of Examples 7 to 8 were manufactured in the same manner as Example 2 except that the ratio of Ni atom, Co atom, and Mn atom was shown in Table 1 by adjusting the charged amount. Produced. Next, for Examples 7 to 8, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, it was confirmed that good battery characteristics were observed in Example 7 and Example 8. From this result, it was confirmed that substantially good battery stability was realized in a wide composition range regardless of the abundance ratio of Ni atoms, Co atoms, and Mn atoms.

<Example 9 to Example 14>
Example 9 to Example 14 were carried out in the same manner as Example 2 except that the charging voltage was changed as shown in Table 1 and the coating thickness of the negative electrode 3 was described below. A secondary battery was produced. In Example 9, the thickness of the negative electrode 3 was 129 μm. In Example 10, the thickness of the negative electrode 3 was 133 μm. In Example 11, the thickness of the negative electrode 3 was set to 151 μm. In Example 12, the thickness of the negative electrode 3 was set to 154 μm. In Example 13, the thickness of the negative electrode 3 was 157 μm. In Example 14, the thickness of the negative electrode 3 was 160 μm.

  In Examples 9 to 14, consideration was given to maintaining a constant capacity balance between the positive electrode 2 and the negative electrode 3 by using the negative electrode 3 having a thickness as described above. Next, for Examples 9 to 14, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, according to Examples 9 to 14, a tendency that the rated energy density increases as the charging voltage is increased is observed, and a relatively good discharge capacity ratio and continuous charging time are observed. It was confirmed that it was observed, and it was suggested that a stable effect by providing the PTFE layer between the positive electrode 2 and the separator 4 can be realized in a charging voltage region.

<Example 15 to Example 19>
The stabilization effect when the thickness of the PTFE layer was changed in terms of basis weight was verified. Secondary batteries of Examples 15 to 19 were manufactured in the same manner as Example 2 except that the basis weight was as shown in Table 1. Next, for Examples 15 to 19, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, it was confirmed that in this measurement region, a stabilizing effect superior to that of Comparative Example 1 was exhibited under any conditions. However, it has been found that when the basis weight is excessive, the apparent electrode reaction rate decreases and the discharge capacity ratio tends to decrease.

<Example 20 to Example 24>
The relationship between the decrease in battery stability generated under high charging voltage conditions and the thickness of the separator 4 was verified. Secondary batteries of Examples 20 to 24 were fabricated in the same manner as in Example 2, except that the thickness of the separator 4 was as shown in Table 1. Next, for Example 20 to Example 24, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, when the thickness of the separator 4 is thin, the continuous charging time tends to be slightly deteriorated, but the improvement effect by the PTFE layer is realized by comparison with Comparative Example 1. There was found.

<Example 25>
Except for using a microporous membrane having a three-layer structure in which a polyethylene layer having a thickness of 6 μm is laminated in the middle of two 7 μm-thick polypropylene layers as the separator 4, two examples of Example 25 are used. A secondary battery was produced. Next, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

<Example 26>
A secondary battery of Example 26 was fabricated in the same manner as in Example 2 except that hard carbon (Carbotron P, Kurewa Chemical) was used as the negative electrode active material and the total thickness of the negative electrode 3 was 230 μm. Next, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the negative electrode material was changed to hard carbon, it was confirmed that favorable battery characteristics were obtained as a result of effectively suppressing the chemical reaction between the positive electrode 2 and the separator 4. .

<Example 27>
A secondary battery of Example 27 was made in the same manner as Example 25 except that granular silicon was used as the negative electrode active material and the total thickness of the negative electrode was 10 μm. Next, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the negative electrode material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

<Example 28>
A secondary battery of Example 28 is fabricated in the same manner as in Example 25 except that tin (tin) electrolessly plated on copper foil is used as the negative electrode active material, and the total thickness of the negative electrode 3 is 60 μm. did. Next, for Example 28, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the negative electrode material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

<Example 29>
A mixture of carbon and an alloy composed of tin and cobalt was used as the negative electrode active material, and the same as Example 25, except that the respective mixing ratios were 20 wt% and 80 wt%, and the total thickness of the negative electrode 3 was 100 μm. Thus, a secondary battery of Example 29 was produced. Next, for Example 29, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the negative electrode material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

<Example 30>
A secondary battery of Example 30 was fabricated in the same manner as in Example 25 except that lithium metal vacuum-deposited on copper foil was used as the negative electrode active material, and the total thickness of the negative electrode 3 was 60 μm. Next, for Example 30, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the negative electrode material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

<Example 31>
A secondary battery of Example 31 was made in the same manner as Example 25 except that the total thickness of the negative electrode 3 was 100 μm. Next, in the same manner as in Example 25, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results. In Example 31, the effect of a novel negative electrode as described in Japanese Patent No. 3573102 was verified. That is, a secondary battery of Example 31 was prototyped using a negative electrode active material in which a carbon material and lithium metal were combined during full charge, and the battery characteristics were evaluated.

  As shown in Table 1, even when the negative electrode material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

<Example 32>
A secondary battery of Example 32 was made in the same manner as Example 25 except that a suspension in which polyvinylidene fluoride fine particles were dispersed was used and the coating material was PVdF. Next, for Example 32, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the coating material was changed, it was confirmed that favorable battery characteristics were obtained as a result of effectively suppressing the chemical reaction between the positive electrode 2 and the separator 4.

<Example 33>
Except for the point that this polymer was used as the coating material, using a suspension in which fine particles made of a copolymer of polyvinylidene fluoride and polyhexafluoropropylene having a copolymerization ratio of 95% and 5% were dispersed. A secondary battery of Example 33 was made in the same manner as Example 25. Next, for Example 33, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the coating material was changed, it was confirmed that favorable battery characteristics were obtained as a result of effectively suppressing the chemical reaction between the positive electrode 2 and the separator 4.

<Example 34, Comparative Example 4 to Comparative Example 6>
<Example 34>
A secondary battery of Example 34 was made in the same manner as Example 1 except that the positive electrode active material was LiNi _0.5 Ti _0.5 MnO ₄ and the total thickness of the positive electrode 2 was 150 μm.

<Comparative Example 4 to Comparative Example 6>
Secondary batteries of Comparative Examples 4 to 6 were fabricated in the same manner as in Example 34 except that the charging voltage, the coating material, the coating weight, and the material of the separator 4 were as shown in Table 1.

  Next, with respect to Example 34 and Comparative Examples 4 to 6, the rated energy density, the discharge capacity ratio, and the continuous charging time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the positive electrode active material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

<Example 35, Comparative Example 7 to Comparative Example 9>
<Example 35>
A secondary battery of Example 35 was made in the same manner as Example 1 except that the positive electrode active material was LiCoPO ₄ and the total thickness of the positive electrode 2 was 160 μm.

<Comparative Example 7 to Comparative Example 9>
Secondary batteries of Comparative Examples 7 to 9 were manufactured in the same manner as in Example 35 except that the charging voltage, the coating material, the coating weight per unit area, and the material of the separator 4 were as shown in Table 1.

  Next, for Example 35 and Comparative Examples 7 to 9, the rated energy density, the discharge capacity ratio, and the continuous charge time were measured. Table 1 shows the measurement results.

  As shown in Table 1, even when the positive electrode active material was changed, it was confirmed that favorable battery characteristics were obtained as a result of the chemical reaction between the positive electrode 2 and the separator 4 being effectively suppressed.

  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. Absent.

  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.

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 the schematic which shows the structure of the nonaqueous electrolyte battery by 2nd Embodiment of this invention. FIG. 4 is an enlarged cross section of a part of the battery element shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery can 2 ... Positive electrode 2A ... Positive electrode collector 2B ... Positive electrode mixture layer 2c ... Fluorine resin layer 3A ... Negative electrode collector 3B ... Negative electrode mixture layer DESCRIPTION OF SYMBOLS 3 ... Negative electrode 4 ... Separator 5,6 ... Insulating plate 7 ... Battery cover 8 ... Safety valve mechanism 9 ... Heat sensitive resistance element 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 42c ... Fluorine resin layer 43 ... Negative electrode 43A ... Negative electrode current collector 43B ... Negative electrode mixture layer 44 ... Separator 45 ... Gel electrolyte layer

Claims (12)

A nonaqueous electrolyte battery having a positive electrode, a negative electrode, a nonaqueous electrolyte, and a separator, 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 4.25 V to 6.00 V Because
A nonaqueous electrolyte battery, wherein a porous layer made of a fluorine-containing polymer is provided between the separator and the positive electrode. In claim 1,
The non-aqueous electrolyte battery, wherein the porous layer is provided at an interface between the separator and the positive electrode. In claim 1,
The non-aqueous electrolyte battery, wherein the porous layer is made of polytetrafluoroethylene or a copolymer containing the polytetrafluoroethylene. In claim 1,
The non-aqueous electrolyte battery, wherein the porous layer is made of polyvinylidene fluoride or a copolymer containing the polyvinylidene fluoride. In claim 1,
A non-aqueous electrolyte battery characterized in that the basis weight of the porous layer is 0.1 mg / cm ² or more and 10 mg / cm ² or less. In claim 1,
The negative electrode has a negative electrode active material,
The non-aqueous electrolyte battery, wherein the negative electrode active material is made of a carbonaceous material. In claim 1,
The negative electrode has a negative electrode active material,
The non-aqueous electrolyte battery, wherein the negative electrode active material is composed of a material that forms an intermetallic compound with lithium (Li) metal. In claim 1,
The negative electrode has a negative electrode active material,
The non-aqueous electrolyte battery, wherein the negative electrode active material is composed of silicon. In claim 1,
The negative electrode has a negative electrode active material,
The non-aqueous electrolyte battery, wherein the negative electrode active material is composed of lithium (Li) metal. In claim 1,
The positive electrode has a positive electrode active material,
The non-aqueous electrolyte battery, wherein the positive electrode active material is composed of a layered compound represented by Chemical Formula 1.
(Chemical formula 1)
_{Li p Ni (1-qr)} Mn q M1 r O (2-y) X z
(M1 represents at least one element selected from Group 2 to Group 15 excluding nickel (Ni) and manganese (Mn). X represents at least one of Group 16 elements and Group 17 elements other than oxygen (O). P, q, y, and z are 0 ≦ p ≦ 1.5, 0 ≦ q ≦ 1.0, 0 ≦ r ≦ 1.0, −0.10 ≦ y ≦ 0.20, 0 (It is a value within the range of ≦ z ≦ 0.2.) In claim 1,
The positive electrode has a positive electrode active material,
The non-aqueous electrolyte battery, wherein the positive electrode active material is composed of lithium cobalt oxide. In claim 1,
The positive electrode has a positive electrode active material,
The non-aqueous electrolyte battery, wherein the positive electrode active material is a phosphate represented by Chemical Formula 2:
(Chemical formula 2)
Li _a M2 _b PO ₄
(M2 represents at least one element selected from Group 2 to Group 15. a and b are values within the range of 0 ≦ a ≦ 2.0 and 0.5 ≦ b ≦ 2.0. )

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