JP2008027731A - Positive electrode active material and positive electrode using this and nonaqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive electrode active material having high capacity and capable of obtaining superior characteristics even under a high-temperature environment, a positive electrode using this and a non-aqueous electrolyte battery. <P>SOLUTION: The positive electrode 21 has a positive electrode active material. The positive electrode active material exists in a morphology in which fluorine (F) is solid solution substituted to lithium transition metal compound oxide particles. Furthermore, at least nickel (Ni) and manganese (Mn) exist excessively on the surface of the particles compared with the total particles, and the element composition on the surface of the particles becomes 0.01≤F/O<21 and (Co/[Ni+Mn])<4.5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a positive electrode active material, a positive electrode using the same, and a non-aqueous electrolyte battery. For example, a positive electrode active material suitable for use in a non-aqueous electrolyte battery having a high capacity and high environmental resistance, and a positive electrode using the positive electrode active material And a non-aqueous electrolyte battery.

  2. Description of the Related Art High-capacity secondary batteries are an important device that greatly influences product performance and reduction in size and weight in mobile electronic devices that have been increasing in demand in recent years. In particular, lithium ion secondary batteries have a higher energy density than conventional lead batteries and nickel cadmium batteries, which are conventional aqueous electrolyte secondary batteries. The application range is expected to be expanded by improving the characteristics at high temperatures.

  As positive electrode active materials used in lithium ion secondary batteries, lithium-cobalt composite oxides having a layered rock salt structure, lithium-nickel composite oxides, lithium-manganese composite oxides having a spinel structure have been put into practical use. Yes. Although each has advantages and disadvantages, lithium-cobalt composite oxides are currently widely used because they have the best balance between capacity and thermal stability.

  In a lithium transition metal composite oxide having a layered rock salt structure, in order to improve cycle characteristics and environmental resistance, for example, a method of adding a specific metal salt as described in Patent Document 1, or Patent Document A method for defining the binder in the positive electrode mixture as described in 2 has been proposed.

Japanese Patent Laid-Open No. 7-192721 Japanese Patent Laid-Open No. 10-302768

  Further, for example, in Patent Document 3, aluminum (Al), magnesium (Mn), tin (Sn), indium (In), iron (Fe), copper (Cu), magnesium are further added to the NiCo solid solution system. A technique for improving the discharge capacity by dissolving (Mg), titanium (Ti), zinc (Zn), and molybdenum (Mo) is disclosed. Further, similarly, as a method for solid solution substitution of different elements, techniques disclosed in, for example, Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and the like have been proposed. Furthermore, for example, Patent Document 8, Patent Document 9, and Patent Document 10 propose NiMn-based, NiCoMn-based, and substitution of different elements for this.

Japanese Patent No. 3244314 Japanese Patent No. 3281829 Japanese Patent No. 3064655 JP-A-8-37007 Japanese Patent No. 2996751 JP 2003-238165 A US Patent Application Publication No. 2003/0170540 Japanese Patent Laid-Open No. 2004-296098

  Furthermore, as a technique paying attention to the interface between the positive electrode and the electrolyte, as disclosed in Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 14, Patent Document 15, and Patent Document 16, the lithium transition metal composite A technique for modifying the surface of oxide particles has been proposed. Further, Patent Document 17 discloses a technique for defining the particle surface and internal distribution for a plurality of different elements.

Japanese Patent No. 3172388 JP 2001-28265 A JP 2004-47449 A JP 2000-199517 A JP 2004-14405 A Japanese Patent No. 3301931

Japanese Patent No. 3637344

  Further, as a technique using a different anion species instead of a metal element, for example, as disclosed in Patent Document 18, a method in which a metal oxide is simply mixed and heat-treated, for example, Patent Document 19 and Patent Document 20 are disclosed. Thus, a technique for coating a metal fluoride on the particle surface has been proposed.

JP-A-6-333565 Japanese Patent No. 3157413 Japanese Patent No. 3141858

  Furthermore, in recent years, as a technique for increasing the energy density of a lithium ion battery, a technique for improving the utilization factor of the positive electrode by increasing the upper limit charging voltage has been proposed. For example, as disclosed in Patent Document 21 and Patent Document 22, a method for defining a part of constituent elements as a specific element, and a method for defining a charging method as disclosed in Patent Document 23 are proposed. Has been. These focus on the fact that the amount of lithium in the lithium transition metal composite oxide at full charge decreases compared to conventional cases due to an increase in the upper limit voltage for charging, and this is due to element substitution in the crystal. It is a technology to improve.

JP 2001-68168 A JP 2004-296098 A JP 2004-55539 A

  However, the techniques disclosed in Patent Documents 1 and 2 are insufficient to suppress the deterioration of the active material. Moreover, although the technique disclosed by patent document 3-patent document 10 is a method of suppressing degradation of active material itself, the disclosed content is what reforms to the inside of an active material crystal | crystallization, charge / discharge This is not sufficient because it causes a harmful effect such as a decrease in capacity. Furthermore, although the technique disclosed in Patent Documents 11 to 17 arranges a metal element different from the core material particles on the surface of the core material particles, the charge / discharge capacity is also reduced in this case. In many cases, it was not resistant to use in a high temperature environment. Furthermore, the contents disclosed in Patent Documents 18 to 20 are such that metal fluorides that do not contribute to the capacity remain, but rather inhibit the diffusion of lithium ions, so the scope of application is limited. It was a thing. Furthermore, the technology disclosed in Patent Literature 21 to Patent Literature 23 was actually confirmed by the inventors of the present application using this technology to produce a secondary battery. The capacity drop during output discharge was remarkable, which was insufficient for improving the performance in the actual use range.

  Accordingly, an object of the present invention is to provide a positive electrode active material that has a high capacity and can obtain excellent characteristics even in a high temperature environment, and a positive electrode and a nonaqueous electrolyte battery using the positive electrode active material.

  The inventors of the present application have made extensive studies to solve the above-mentioned problems, and found that there is a synergistic effect between the effect of the anion species and the effect of the cation species in the vicinity of the particle surface. Fluorine (F) exists in a state where it is substituted into the system and does not form a metal fluoride phase, and at least nickel (Ni), manganese (Mn), iron (F), and oxygen (O) are in a predetermined ratio. By using a lithium transition metal composite oxide diffused in the vicinity of the particle surface as the positive electrode active material, a non-aqueous electrolyte battery having a high capacity and excellent characteristics even in a high temperature environment can be realized.

That is, in order to solve the above-described problem, the first invention
The lithium transition metal composite oxide particles exist in a form in which fluorine (F) is replaced by solid solution,
Furthermore, at least nickel (Ni) and manganese (Mn) are present in excess on the surface of the particle as compared to the entire particle,
A positive electrode active material characterized in that the elemental composition of the surface of the particles is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5.

The second invention is
A positive electrode active material,
The positive electrode active material is
The lithium transition metal composite oxide particles exist in a form in which fluorine (F) is replaced by solid solution,
Furthermore, at least nickel (Ni) and manganese (Mn) are present in excess on the surface of the particle as compared to the entire particle,
The positive electrode is characterized in that the elemental composition of the surface of the particles is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5.

The third invention is
A positive electrode including a positive electrode active material, a negative electrode, and an electrolyte;
The positive electrode active material is
The lithium transition metal composite oxide particles exist in a form in which fluorine (F) is replaced by solid solution,
Furthermore, at least nickel (Ni) and manganese (Mn) are present in excess on the surface of the particle as compared to the entire particle,
The non-aqueous electrolyte battery is characterized in that the elemental composition of the surface of the particles is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5.

  According to the present invention, the capacity is high, and excellent characteristics can be obtained even in a high temperature environment.

  Embodiments of the present invention will be described below with reference to the drawings. First, a positive electrode active material according to an embodiment of the present invention will be described.

  The positive electrode active material according to one embodiment of the present invention is present in a form in which fluorine (F) is replaced by solid solution in lithium transition metal composite oxide particles, and at least nickel (Ni) and manganese (Mn) are present throughout the particles. As compared to the above, the elemental composition of the particle surface is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5. For example, fluorine (F) exists in the form of solid solution substitution on the particle surface or inside.

  That is, the positive electrode active material according to one embodiment of the present invention is present in the lithium transition metal composite oxide particles in a state where fluorine (F) is replaced by solid solution in the system and does not form a metal fluoride phase, It has cobalt (Co), nickel (Ni), manganese (Mn), and fluorine (F) as constituent elements, and at least nickel (Ni) and manganese (Mn) are present in excess on the particle surface compared to the whole particle. The elemental composition of the particle surface is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5. Since there is no metal fluoride phase that does not contribute to the charge / discharge capacity and also inhibits the lithium ion migration phenomenon, a high-capacity positive electrode active material can be obtained. Moreover, the nonaqueous electrolyte battery using the positive electrode active material according to one embodiment has excellent characteristics even in a high temperature environment. Furthermore, the non-aqueous electrolyte battery using the positive electrode active material according to an embodiment can achieve a high energy density by setting the upper limit charging voltage higher than the conventional one.

  Further, the elemental composition of the particle surface measured by XPS (X-ray photoelectron spectroscopy) or the like is set to a predetermined ratio [0.01 ≦ F / O <21 and (Co / “Ni + Mn”) By prescribing in <4.5>, it is possible to suppress side reactions at the positive electrode active material / electrolyte interface and to improve the performance particularly in a high temperature environment. Further, the element composition of the entire particle is preferably (Co / “Ni + Mn”)> 2.0. By defining it in this range, high charge / discharge efficiency can be obtained.

  Furthermore, known elements can be added to elements other than cobalt (Co), nickel (Ni), manganese (Mn), and fluorine (F), preferably magnesium (Mg), aluminum (Al), calcium ( Ca), titanium (Ti), vanadium (V), gallium (Ga), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), tin (Sn), tungsten (W), bismuth ( The battery performance can be further improved by adding at least one element selected from the group consisting of Bi). These elements may be present in any part of the particle or on the surface as long as the metal fluoride is not formed.

  Furthermore, the positive electrode active material according to an embodiment and the positive electrode using the positive electrode active material are designed so that the upper limit charging voltage is 4.25 V to 4.70 V, which is higher than that of the current lithium ion secondary battery, and has a high energy density. In the case of using it for a non-aqueous electrolyte battery such as a lithium ion secondary battery, the effect can be exhibited more.

  The method for synthesizing the lithium transition metal composite oxide in one embodiment is not particularly limited. For example, a nickel compound or a halogen compound is mixed with a known lithium cobalt oxide powder and diffused by heat treatment, a method of growing a surface layer from the gas phase, such as vapor deposition or sputtering, and a shearing force is applied to the particles. Any method can be used as long as the specified material configuration can be realized, such as a method of physically coating, a method of depositing a surface layer on the particle surface in a solution, or a method of exposing to a reactive gas such as fluorine gas. It is.

  Using the positive electrode active material according to one embodiment of the present invention, for example, non-aqueous electrolyte batteries such as lithium ion batteries having various shapes and sizes can be produced. Hereinafter, a first example of a nonaqueous electrolyte battery using a positive electrode active material according to an embodiment of the present invention will be described.

  FIG. 1 shows a cross-sectional structure of a nonaqueous electrolyte battery using a positive electrode active material according to an embodiment of the present invention. This nonaqueous electrolyte battery is, for example, a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. This non-aqueous electrolyte battery is a so-called cylindrical type, in which a strip-like positive electrode 21 and a negative electrode 22 are stacked and wound around a separator 11 in a substantially hollow cylindrical battery can 11. An electrode body 20 is provided.

  The battery can 11 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 11, a pair of insulating plates 12 and 13 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 11, a battery lid 14, a safety valve 15 and a heat sensitive resistance element (Positive Temperature Coefficient; PTC element) 16 provided inside the battery lid 14 are provided via a sealing gasket 17. It is attached by caulking, and the inside of the battery can 11 is sealed.

  The battery lid 14 is made of, for example, the same material as the battery can 11. The safety valve 15 is electrically connected to the battery lid 14 via the heat sensitive resistance element 16, and the disk plate 15A is reversed when the internal pressure of the battery exceeds a certain level due to an internal short circuit or external heating. Thus, the electrical connection between the battery lid 14 and the wound electrode body 20 is cut off.

  When the temperature rises, the heat sensitive resistance element 16 limits the current by increasing the resistance value and prevents abnormal heat generation due to a large current. The sealing gasket 17 is made of, for example, an insulating material, and asphalt is applied to the surface.

  For example, a center pin 24 is inserted in the center of the wound electrode body 20. A positive electrode lead 25 made of aluminum (Al) or the like is connected to the positive electrode 21 of the spirally wound electrode body 20, and a negative electrode lead 26 made of nickel (Ni) or the like is connected to the negative electrode 22. The positive electrode lead 25 is electrically connected to the battery lid 14 by being welded to the safety valve mechanism 15, and the negative electrode lead 26 is welded to and electrically connected to the battery can 11.

  FIG. 2 shows an enlarged part of the spirally wound electrode body 20 shown in FIG. The positive electrode 21 includes, for example, a positive electrode current collector 21A having a pair of opposed surfaces and a positive electrode active material layer 21B provided on both surfaces of the positive electrode current collector 21A. The positive electrode active material layer 21B may have a region that exists only on one side. The positive electrode current collector 21A is made of, for example, a metal foil such as an aluminum foil, a nickel foil, or a stainless steel foil.

  The positive electrode active material layer 21B includes the positive electrode active material described above. The positive electrode active material layer 21B also includes, for example, a conductive agent, and may further include a binder as necessary. Examples of the conductive agent include carbon materials such as graphite, carbon black, and ketjen black, and one or more of them are used in combination. In addition to the carbon material, a metal material or a conductive polymer material may be used as long as it is a conductive material.

  Examples of the binder include synthetic rubber such as styrene butadiene rubber, fluorine rubber or ethylene propylene diene rubber, or a polymer material such as polyvinylidene fluoride, and one or more of them are mixed. Used. For example, when the positive electrode 21 and the negative electrode 22 are wound as shown in FIG. 1, it is preferable to use a styrene butadiene rubber or a fluorine rubber having high flexibility as the binder.

  The negative electrode 22 includes, for example, a negative electrode current collector 22A having a pair of opposed surfaces and a negative electrode active material layer 22B provided on both surfaces of the negative electrode current collector 22A. The negative electrode active material layer 22B may have a region where only one side exists.

  The negative electrode current collector 22A is made of, for example, a metal foil such as a copper foil, a nickel foil, or a stainless steel foil having good electrochemical stability, electrical conductivity, and mechanical strength. In particular, copper foil is most preferable because it has high electrical conductivity.

  The negative electrode active material layer 22B includes one or more negative electrode materials capable of inserting and extracting lithium (Li) as a negative electrode active material. The binder similar to the positive electrode active material layer 21B may be included.

  As the negative electrode material, any material can be used as long as it is electrochemically doped / undoped with lithium at a potential of lithium metal of 2.0 V or less. For example, non-graphitizable carbon, artificial graphite, natural graphite, pyrolytic carbons, cokes (pitch coke, needle coke, petroleum coke, etc.), graphites, glassy carbons, and fired organic polymer compounds Carbonaceous materials such as (carbonized by firing phenol resin, furan resin, etc. at an appropriate temperature), carbon fibers, activated carbon, carbon blacks and the like can be used. In addition, metals capable of forming an alloy with lithium and alloys and intermetallic compounds thereof can also be used. Oxides such as iron oxide, ruthenium oxide, molybdenum oxide, tungsten oxide, titanium oxide, tin oxide, etc. that dope and dedoped lithium with a relatively low potential, and other nitrides can also be used. There is no particular limitation on the form of the negative electrode, and it is possible to use a material in which an active material layer is formed on a current collector by a method such as vapor deposition in addition to a material coated with an active material powder.

  As the electrolyte, a nonaqueous electrolytic solution in which an electrolyte salt is dissolved in an organic solvent can be used. The nonaqueous electrolytic solution is adjusted by appropriately combining an organic solvent and an electrolyte. Examples of the organic solvent include propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, vinylene carbonate, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1, Examples thereof include 3-dioxolane, 4-methyl-1,3-dioxolane, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, propionitrile, anisole, acetate ester, butyrate ester, propionate ester and the like.

Any electrolyte salt can be used as long as it is used for this type of battery. Examples thereof include LiClO ₄ , LiAsF _6, LiPF ₆ , LiBF ₄ , LiB (C ₆ H ₅ ) ₄ , CH ₃ SO ₃ Li, CF ₃ SO ₃ Li, LiCl, and LiBr.

  As the separator 23, for example, a polyolefin microporous film such as polyethylene or polypropylene can be used.

  Next, an example of the manufacturing method of the 1st example of a nonaqueous electrolyte battery is demonstrated. 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 (NMP). A paste-like positive electrode mixture slurry is prepared. Next, the positive electrode mixture slurry is applied to the positive electrode current collector 21A, the solvent is dried, and the positive electrode active material layer 21B is formed by compression molding using a roll press or the like. Thereby, the positive electrode 31 is obtained.

  Further, 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 (NMP) to form a paste-like negative electrode A mixture slurry is prepared. Next, the negative electrode mixture slurry is applied to the negative electrode current collector 22A, the solvent is dried, and the negative electrode active material layer 22B is formed by compression molding using a roll press or the like. Thereby, the negative electrode 22 is obtained.

  Subsequently, the positive electrode lead 25 is attached to the positive electrode current collector 21A by welding or the like, and the negative electrode lead 26 is attached to the negative electrode current collector 22A by welding or the like. After that, the positive electrode 21 and the negative electrode 22 are wound through the separator 23, the tip of the positive electrode lead 25 is welded to the safety valve mechanism 15, and the tip of the negative electrode lead 26 is welded to the battery can 11. The positive electrode 21 and the negative electrode 22 are sandwiched between a pair of insulating plates 12 and 13 and stored in the battery can 11. After the positive electrode 21 and the negative electrode 22 are accommodated in the battery can 11, the electrolytic solution is injected into the battery can 11 and impregnated in the separator 23. After that, the battery lid 14, the safety valve device 15, and the heat sensitive resistance element 16 are fixed to the opening end portion of the battery can 11 by caulking through the gasket 17. Thereby, the nonaqueous electrolyte battery shown in FIG. 2 is obtained.

  In this nonaqueous electrolyte battery, for example, when charged, lithium ions are released from the positive electrode active material layer 21B, and lithium (Li) contained in the negative electrode active material layer 22B is occluded and released through the electrolytic solution. Is occluded in the negative electrode material. Next, when discharge is performed, lithium ions occluded in the negative electrode material capable of inserting and extracting lithium (Li) in the negative electrode active material layer 22B are released, and the positive electrode active material layer 21B is passed through the electrolytic solution. Occluded.

  Next, a second example of the nonaqueous electrolyte battery will be described. FIG. 3 is a cross-sectional view showing a configuration example of a second example of the nonaqueous electrolyte battery. In this nonaqueous electrolyte battery, the wound electrode body 30 to which the positive electrode lead 31 and the negative electrode lead 32 are attached is housed in a film-like exterior member 40, and can be reduced in size, weight, and thickness. It has become.

  Each of the positive electrode lead 31 and the negative electrode lead 32 is led out from the inside of the exterior member 40 to the outside, for example, in the same direction. The positive electrode lead 31 and the negative electrode lead 32 are each made of a metal material such as aluminum (Al), copper (Cu), nickel (Ni), or stainless steel (SUS), and each have a thin plate shape or a mesh shape. Yes.

  The exterior member 40 is made of, for example, a rectangular aluminum laminated film in which a nylon film, an aluminum foil, and a polyethylene film are bonded together in this order. For example, the exterior member 40 is disposed so that the polyethylene film side and the wound electrode body 30 face each other, and the outer edge portions are in close contact with each other by fusion bonding or an adhesive. An adhesive film 41 is inserted between the exterior member 40 and the positive electrode lead 31 and the negative electrode lead 32 to prevent intrusion of outside air. The adhesion film 41 is made of a material having adhesion to the positive electrode lead 31 and the negative electrode lead 32, for example, a polyolefin resin such as polyethylene, polypropylene, modified polyethylene, or modified polypropylene.

  The exterior member 40 may be made of a laminated film having another structure, a polymer film such as polypropylene, or a metal film instead of the above-described aluminum laminated film.

  FIG. 4 is a cross-sectional view taken along the line II of the spirally wound electrode body 30 shown in FIG. The wound electrode body 30 is obtained by laminating and winding a positive electrode 33 and a negative electrode 34 with a separator 35 and an electrolyte layer 36 interposed therebetween, and the outermost peripheral portion is protected by a protective tape 37.

  The positive electrode 33 has a structure in which a positive electrode active material layer 33B is provided on one or both surfaces of a positive electrode current collector 33A. The negative electrode 34 has a structure in which a negative electrode active material layer 34B is provided on one surface or both surfaces of a negative electrode current collector 34A, and the negative electrode active material layer 34B and the positive electrode active material layer 33B are arranged to face each other. Yes. The configuration of the positive electrode current collector 33A, the positive electrode active material layer 33B, the negative electrode current collector 34A, the negative electrode active material layer 34B, and the separator 35 is the same as that of the positive electrode current collector 21A, the positive electrode active material layer 21B described in the first example, This is the same as the anode current collector 22A, the anode active material layer 23B, and the separator 35.

  The electrolyte layer 36 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 36 is preferable because high ion conductivity can be obtained and battery leakage can be prevented. As the polymer compound, various polymer compounds can be used as long as they absorb the electrolyte and gel. For example, fluorine-based polymers such as poly (vinylidene fluoride) and poly (vinylidene fluoride-co-hexafluoropropylene), ether-based polymers such as poly (ethylene oxide) and the same cross-linked products, poly (acrylonitrile), etc. Can be used. In particular, it is desirable to use a fluorine-based polymer from the viewpoint of redox stability. By containing an electrolyte salt, ionic conductivity is imparted. In addition, you may use for electrolyte as it is as a liquid electrolyte, without hold | maintaining electrolyte solution to a high molecular compound.

  Next, an example of the manufacturing method of the 2nd example of a nonaqueous electrolyte battery is demonstrated. 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 33 and the negative electrode 34, and the mixed solvent is volatilized to form a gel electrolyte layer 36. After that, the positive electrode lead 31 is attached to the end of the positive electrode current collector 33A by welding, and the negative electrode lead 32 is attached to the end of the negative electrode current collector 34A by welding.

  Next, the positive electrode 33 and the negative electrode 34 on which the gel electrolyte layer 36 is formed are laminated through a separator 35 to form a laminated body, and then the laminated body is wound in the longitudinal direction to protect the outermost peripheral portion. The wound electrode body 30 is formed by adhering the tape 37. Finally, for example, the wound electrode body 30 is sandwiched between the exterior members 40, and the outer edges of the exterior members 40 are sealed and sealed by heat fusion or the like. At that time, the adhesion film 41 is inserted between the positive electrode lead 31 and the negative electrode lead 32 and the exterior member 40. Thereby, the nonaqueous electrolyte battery shown in FIGS. 3 and 4 is obtained.

  Further, this nonaqueous electrolyte battery may be manufactured as follows. First, the positive electrode 33 and the negative electrode 34 are prepared as described above, and after the positive electrode lead 31 and the negative electrode lead 32 are attached to the positive electrode 33 and the negative electrode 34, the positive electrode 33 and the negative electrode 34 are stacked via the separator 35 and wound. Rotate and adhere the protective tape 37 to the outermost periphery to form a wound body that is a precursor of the wound electrode body 30. Next, the wound body is sandwiched between the exterior members 40, and the outer peripheral edge except for one side is heat-sealed to form a bag shape, which is then stored inside the exterior member 40. Subsequently, an electrolyte composition including a solvent, an electrolyte salt, a monomer that is a raw material of the polymer compound, a polymerization initiator, and other materials such as a polymerization inhibitor as necessary is prepared, and the exterior member Inject into 40.

  After injecting the electrolyte composition, the opening of the exterior member 40 is heat-sealed and sealed in a vacuum atmosphere. Next, the gelled electrolyte layer 36 is formed by applying heat to polymerize the monomer to obtain a polymer compound. As described above, the nonaqueous electrolyte battery shown in FIGS. 3 and 4 is obtained.

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

<Example 1>
The positive electrode active material was produced as described below. First, commercially available cobalt oxide and lithium carbonate were mixed to obtain a calcined precursor. This calcined precursor was calcined at 950 ° C. for 7 hours using an electric furnace, and pulverized to obtain LiCoO ₂ powder. After mixing 1 mol of this powder with 0.05 mol of nickel fluoride powder, 0.05 mol of manganese dioxide powder, and 0.10 mol of lithium carbonate powder, the mixture was sufficiently pulverized and mixed in an automatic mortar and then at 900 ° C. for 10 hours. Heat treatment was applied. The nickel fluoride phase was completely decomposed, and no peak corresponding to the metal fluoride was observed in the X-ray diffraction measurement.

  This lithium transition metal composite oxide was subjected to composition analysis on the outermost surface by X-ray photoelectron spectroscopy (XPS). As a result, F / O = 0.58 and (Co / “Ni + Mn”) = 2.12. . Further, when the composition of the whole particle was determined by ICP emission spectrometry (Inductively coupled plasma emission spectrometry), (Co / “Ni + Mn”) = 8.92, and nickel (Ni) and manganese (Mn) were present on the particle surface. Existence in excess was confirmed. Using the above powder as the positive electrode active material, a nonaqueous electrolyte battery having a cylindrical shape was produced as described below, and the cycle characteristics at high temperature were evaluated.

  First, 86% by weight of the positive electrode active material, 10% by weight of graphite as a conductive agent, and 4% by weight of polyvinylidene fluoride (PVdF) as a binder are mixed and dispersed in N-methyl-2-pyrrolidone (NMP). Thus, a positive electrode mixture slurry was obtained. This slurry was uniformly applied to both sides of a 20 μm-thick strip-shaped aluminum foil, dried, and then compressed by a roller press to obtain a strip-shaped positive electrode.

  Next, 90% by weight of powdered artificial graphite was mixed with 10% by weight of polyvinylidene fluoride (PVdF) and dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a negative electrode mixture slurry. This negative electrode mixture slurry was uniformly applied on both sides of a 10 μm thick copper foil, and after drying, it was compressed with a roller press to obtain a belt-like negative electrode.

  Next, the produced strip-shaped positive electrode and strip-shaped negative electrode were laminated via a porous polyolefin film, and then wound many times to obtain a spiral wound electrode body. Next, the wound electrode body was housed in a nickel-plated iron battery can, and insulating plates were arranged on both the upper and lower surfaces of the wound electrode body.

  Next, the aluminum positive electrode lead is led out from the positive electrode current collector and welded to the protrusion of the safety valve that is electrically connected to the battery lid, and the nickel negative electrode lead is led out from the negative electrode current collector. Welded to the bottom of the can.

Finally, after injecting the electrolyte into the battery can in which the wound electrode body is incorporated, the safety can, the PTC element and the battery lid are fixed by caulking the battery can through the insulating sealing gasket, and the outer diameter is A nonaqueous electrolyte battery of Example 1 having a cylindrical shape of 18 mm and a height of 65 mm was produced. As the electrolytic solution, a solution obtained by dissolving LiPF ₆ in a mixed solvent having a volume mixing ratio of ethylene carbonate and methyl ethyl carbonate of 1: 1 to a concentration of 1 mol / dm ³ was used.

  The nonaqueous electrolyte battery of Example 1 manufactured as described above was charged under the conditions of an environmental temperature of 45 ° C., a charging voltage of 4.40 V, a charging current of 1000 mA, and a charging time of 2.5 hours, and then a discharging current of 800 mA. The battery was discharged at a final voltage of 2.75 V, and the initial capacity was measured. Furthermore, charge / discharge was repeated in the same manner as when the initial capacity was determined, and the discharge capacity at the 200th cycle was measured to determine the capacity retention rate relative to the initial capacity.

<Example 2>
By adjusting the mixing ratio of nickel fluoride, manganese dioxide and lithium carbonate and heat treatment conditions in the positive electrode active material preparation step, the composition on the surface is F / O = 0.01, (Co / "Ni + Mn" ) = 3.44 A lithium transition metal composite oxide was obtained. The composition of the whole particle was (Co / “Ni + Mn”) = 9.18. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 2 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 2, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1.

<Example 3>
In the preparation process of the positive electrode active material, the ratio at the time of mixing nickel fluoride, manganese dioxide and lithium carbonate and the heat treatment conditions are adjusted so that the composition on the surface is F / O = 1.85, (Co / "Ni + Mn" ) = 3.18 A lithium transition metal composite oxide was obtained. The composition of the entire particle was (Co / “Ni + Mn”) = 9.01. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 3 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 3, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1.

<Example 4>
In the preparation process of the positive electrode active material, the composition on the surface is F / O = 8.22, (Co / “Ni + Mn”) by adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate ) = 4.45 A lithium transition metal composite oxide was obtained. The composition of the entire particle was (Co / “Ni + Mn”) = 8.37. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 4 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 4, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1.

<Example 5>
In the preparation process of the positive electrode active material, the composition on the surface is F / O = 14.6, (Co / “Ni + Mn”) by adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate ) = 2.76 A lithium transition metal composite oxide was obtained. The composition of the entire particle was (Co / “Ni + Mn”) = 8.51. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 5 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 5, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 6>
In the preparation process of the positive electrode active material, the composition on the surface is F / O = 20.8, (Co / “Ni + Mn”) by adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate ) = 3.00 A lithium transition metal composite oxide was obtained. The composition of the whole particle was (Co / “Ni + Mn”) = 8.43. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 6 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 6, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 7>
In the preparation process of the positive electrode active material, the composition on the surface is F / O = 5.86, (Co / “Ni + Mn”) by adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate ) = 1.12 A lithium transition metal composite oxide was obtained. The composition of the whole particle was (Co / “Ni + Mn”) = 5.24. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 7 was produced in the same manner as Example 1. For the nonaqueous electrolyte battery of Example 7, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 8>
In the preparation process of the positive electrode active material, the composition on the surface is F / O = 8.32, (Co / “Ni + Mn”) by adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate ) = 0.89 A lithium transition metal composite oxide was obtained. The composition of the whole particle was (Co / “Ni + Mn”) = 2.04. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 8 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 8, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 9>
In the preparation process of the positive electrode active material, the composition on the surface is F / O = 10.1, (Co / “Ni + Mn”) by adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate ) = 0.70 to obtain a lithium transition metal composite oxide. The composition of the entire particle was (Co / “Ni + Mn”) = 1.39. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 9 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 9, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 10>
In the production process of the positive electrode active material, the composition on the surface was F / O = 0.72, (Co /) in the same manner as in Example 1 except that nickel oxide and lithium fluoride were used instead of nickel fluoride. A lithium transition metal composite oxide satisfying “Ni + Mn”) = 1.92 was obtained. The composition of the entire particle was (Co / “Ni + Mn”) = 8.88. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 10 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 10, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 11>
In the preparation process of the positive electrode active material, when mixing cobalt oxide and lithium carbonate, the same as Example 1 except that magnesium carbonate and aluminum oxide were mixed at 1 mol% relative to cobalt (Co) at the same time. Thus, a lithium transition metal composite oxide containing magnesium (Mg) and aluminum (Al) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.61, (Co / “Ni + Mn”) = 2.07, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.90. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 11 was produced in the same manner as Example 1. For the nonaqueous electrolyte battery of Example 11, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 12>
In the production process of the positive electrode active material, when mixing nickel fluoride, manganese dioxide, and lithium carbonate, the same as Example 1 except that magnesium carbonate was mixed at 1 mol% relative to cobalt (Co) at the same time. Thus, a lithium transition metal composite oxide containing magnesium (Mg) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.60, (Co / “Ni + Mn”) = 2.10, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.87. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 12 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 12, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 13>
In the preparation process of the positive electrode active material, when mixing nickel fluoride, manganese dioxide and lithium carbonate, aluminum hydroxide was mixed at the same time with 1 mol% compared to cobalt (Co), and Example 1 and Similarly, a lithium transition metal composite oxide containing aluminum (Al) was obtained. The composition of the lithium transition metal composite oxide on the surface is F / O = 0.59, (Co / “Ni + Mn”) = 2.02, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.91. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 13 was produced in the same manner as Example 1. For the nonaqueous electrolyte battery of Example 13, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 14>
In the preparation process of the positive electrode active material, when mixing nickel fluoride, manganese dioxide and lithium carbonate, the same as in Example 1 except that calcium hydroxide was mixed at 0.5 mol% relative to cobalt at the same time. Thus, a lithium transition metal composite oxide containing calcium (Ca) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.63, (Co / “Ni + Mn”) = 2.20, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.92. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 14 was produced in the same manner as in Example 1. Further, with respect to the nonaqueous electrolyte battery of Example 14, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1.

<Example 15>
In the preparation process of the positive electrode active material, when mixing nickel fluoride, manganese dioxide and lithium carbonate, titanium oxide was mixed at the same time with 0.5 mol% relative to cobalt (Co), except that it was mixed with Example 1. Similarly, a lithium transition metal composite oxide containing titanium (Ti) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.62, (Co / “Ni + Mn”) = 1.98, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.90. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 15 was produced in the same manner as Example 1. For the nonaqueous electrolyte battery of Example 15, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 16>
Example 1 except that nickel fluoride, manganese dioxide, and lithium carbonate were mixed at the same time in the preparation process of the positive electrode active material, and at the same time vanadium oxide was mixed in an amount corresponding to 0.5 mol% relative to cobalt (Co). In the same manner as above, a lithium transition metal composite oxide containing vanadium (V) was obtained. The composition of the lithium transition metal composite oxide on the surface is F / O = 0.64, (Co / “Ni + Mn”) = 2.05, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.89. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 16 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 16, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 17>
Example 1 except that when mixing nickel fluoride, manganese dioxide, and lithium carbonate in the step of preparing the positive electrode active material, gallium nitrate was mixed at 0.5 mol% relative to cobalt (Co) at the same time. In the same manner as above, a lithium transition metal composite oxide containing gallium (Ga) was obtained. The composition of the lithium transition metal composite oxide on the surface is F / O = 0.60, (Co / “Ni + Mn”) = 2.21, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.94. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 17 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 17, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 18>
Example 1 except that nickel fluoride, manganese dioxide and lithium carbonate were mixed at the same time in the preparation process of the positive electrode active material, and at the same time, yttrium oxide was mixed in an amount corresponding to 0.5 mol% relative to cobalt (Co). In the same manner as above, a lithium transition metal composite oxide containing yttrium (Y) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.58, (Co / “Ni + Mn”) = 1.94, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.92. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 18 was produced in the same manner as Example 1. For the nonaqueous electrolyte battery of Example 18, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 19>
Example 1 except that, in the step of preparing the positive electrode active material, when nickel fluoride, manganese dioxide, and lithium carbonate were mixed, zirconium oxide was mixed in an amount corresponding to 0.5 mol% relative to cobalt (Co). In the same manner as above, a lithium transition metal composite oxide containing zirconium (Zr) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.61, (Co / “Ni + Mn”) = 2.10, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.79. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 19 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 19, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 20>
Example 1 except that in the preparation process of the positive electrode active material, nickel fluoride, manganese dioxide and lithium carbonate were mixed, and at the same time, niobium oxide was mixed in an amount corresponding to 0.5 mol% relative to cobalt (Co). In the same manner as above, a lithium transition metal composite oxide containing niobium (Nb) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.64, (Co / “Ni + Mn”) = 2.16, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.95. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 20 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 20, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 21>
In the production process of the positive electrode active material, when mixing nickel fluoride, manganese dioxide and lithium carbonate, Example 1 and Example 1 except that molybdenum oxide was mixed at 0.5 mol% relative to cobalt (Co) at the same time. Similarly, a lithium transition metal composite oxide containing molybdenum (Mo) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.58, (Co / “Ni + Mn”) = 2.00, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.88. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 21 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 21, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 22>
Example 1 except that, in the step of preparing the positive electrode active material, when nickel fluoride, manganese dioxide, and lithium carbonate were mixed, tin oxide was mixed at 0.5 mol% relative to cobalt (Co) at the same time. In the same manner as above, a lithium transition metal composite oxide containing tin (Sn) was obtained. The composition of the lithium transition metal composite oxide on the surface is F / O = 0.57, (Co / “Ni + Mn”) = 2.07, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.94. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 22 was produced in the same manner as in Example 1. Further, with respect to the nonaqueous electrolyte battery of Example 22, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1.

<Example 23>
Example 1 except that, in the step of preparing the positive electrode active material, when nickel fluoride, manganese dioxide, and lithium carbonate are mixed, tungsten oxide is mixed at 0.5 mol% relative to cobalt (Co) at the same time. In the same manner as above, a lithium transition metal composite oxide containing tungsten (W) was obtained. The composition on the surface of this lithium transition metal composite oxide is F / O = 0.63, (Co / “Ni + Mn”) = 2.09, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.78. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 23, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Example 24>
Example 1 except that nickel fluoride, manganese dioxide, and lithium carbonate were mixed in the positive electrode active material preparation step, and at the same time, bismuth oxide was mixed in an amount corresponding to 0.5 mol% relative to cobalt (Co). Similarly, a lithium transition metal composite oxide containing bismuth (Bi) was obtained. The composition of the lithium transition metal composite oxide on the surface is F / O = 0.60, (Co / “Ni + Mn”) = 1.96, and the composition of the entire particle is (Co / “Ni + Mn”) = 8.91. Met. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Example 24 was produced in the same manner as in Example 1. For the nonaqueous electrolyte battery of Example 24, the initial capacity and capacity retention rate were measured in the same manner as in Example 1.

<Comparative Example 1>
In the production process of the positive electrode active material, nickel oxide is used instead of nickel fluoride, and the ratio at the time of mixing manganese dioxide and lithium carbonate and the heat treatment conditions are adjusted, so that the composition on the surface becomes F / O = 0. As a result, a lithium transition metal composite oxide satisfying 0.000 (Co / “Ni + Mn”) = 2.62 was obtained. The composition of the entire particle was (Co / “Ni + Mn”) = 8.91. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Comparative Example 1 was produced in the same manner as in Example 1. Further, the initial capacity and capacity retention rate of the nonaqueous electrolyte battery of Comparative Example 1 were measured in the same manner as in Example 1.

<Comparative example 2>
By adjusting the ratio and heat treatment conditions when mixing nickel fluoride, manganese dioxide and lithium carbonate in the positive electrode active material preparation process, the composition on the surface is F / O = 36.5, (Co / "Ni + Mn" ) = 1.86 Lithium transition metal composite oxide was obtained. The composition of the entire particle was (Co / “Ni + Mn”) = 8.52. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Comparative Example 2 was produced in the same manner as in Example 1. Further, the initial capacity and capacity retention rate of the nonaqueous electrolyte battery of Comparative Example 2 were measured in the same manner as in Example 1.

<Comparative Example 3>
By adjusting the mixing ratio of nickel fluoride, manganese dioxide and lithium carbonate and the heat treatment conditions in the production process of the positive electrode active material, the composition on the surface is F / O = 38.1, (Co / “Ni + Mn” ) = 5.29 A lithium transition metal composite oxide was obtained. The composition of the whole particle was (Co / “Ni + Mn”) = 8.07. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Comparative Example 3 was produced in the same manner as in Example 1. Further, the initial capacity and capacity retention rate of the nonaqueous electrolyte battery of Comparative Example 3 were measured in the same manner as in Example 1.

<Comparative Example 4>
In the production process of the positive electrode active material, the heat treatment temperature was set to 300 ° C., so that a lithium transition metal composite oxide in which nickel fluoride was not completely dissolved and the nickel fluoride phase remained was obtained. When X-ray diffraction measurement was performed, diffraction lines were confirmed at the same angle as the raw material nickel fluoride, and the composition on the surface was F / O = 4.21, (Co / “Ni + Mn”) = 0.64, The composition of the entire particle was (Co / “Ni + Mn”) = 8.94. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Comparative Example 4 was produced in the same manner as in Example 1. Further, the initial capacity and capacity retention rate of the nonaqueous electrolyte battery of Comparative Example 4 were measured in the same manner as in Example 1.

<Comparative Example 5>
In the preparation process of the positive electrode active material, the composition at the surface is F / O = 0.96 and (Co / “Ni + Mn”) = 4.81 by adjusting the mixing ratio of manganese dioxide and the heat treatment conditions. A lithium transition metal composite oxide was obtained. The composition of the whole particle was (Co / “Ni + Mn”) = 9.27. Using this lithium transition metal composite oxide, a nonaqueous electrolyte battery of Comparative Example 5 was produced in the same manner as in Example 1. Further, the initial capacity and capacity retention rate of the nonaqueous electrolyte battery of Comparative Example 5 were measured in the same manner as in Example 1.

  Table 1 shows the measurement results of the initial capacities and capacity retention rates of Examples 1 to 24 and Comparative Examples 1 to 5.

  As shown in Table 1, according to the comparison between Example 1 to Example 24 and Comparative Example 1 to Comparative Example 5, fluorine exists as a solid solution in the system and does not form a metal fluoride phase. And at least nickel (Ni), manganese (Mn), and fluorine (F) are excessively present on the particle surface as compared with the whole particle, and the elemental composition on the particle surface is 0.01 ≦ F / O <21, and ( Co / "Ni + Mn") <4.5 Non-aqueous electrolyte battery using a lithium transition metal composite oxide as a positive electrode active material has a high capacity and can be improved at high temperature. . Further, it was found that the elemental composition of the entire particle is preferably (Co / “Ni + Mn”)> 2.0.

  Further, according to comparison between Example 1 to Example 10 and Example 11 to Example 24, magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), vanadium (V), gallium At least one element selected from the group consisting of (Ga), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), tin (Sn), tungsten (W), and bismuth (Bi) It was found that the performance can be further improved by adding.

<Example 25>
In the production process of the positive electrode active material, the non-aqueous electrolyte of Example 25 was prepared in the same manner as in Example 1 except that the electrode was designed so that the charging voltage was 4.20 V when the non-aqueous electrolyte battery was produced. An electrolyte battery was produced. For the nonaqueous electrolyte battery of Example 25, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.20V.

<Example 26>
In the production process of the positive electrode active material, the non-aqueous electrolyte of Example 26 was prepared in the same manner as in Example 1 except that the electrode was designed so that the charging voltage was 4.25 V when the non-aqueous electrolyte battery was produced. An electrolyte battery was produced. For the nonaqueous electrolyte battery of Example 26, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.25V.

<Example 27>
In the production process of the positive electrode active material, the nonaqueous electrolyte of Example 27 was obtained in the same manner as in Example 1 except that the electrode was designed so that the charging voltage was 4.35 V when producing the nonaqueous electrolyte battery. An electrolyte battery was produced. For the nonaqueous electrolyte battery of Example 27, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.35V.

<Example 28>
In the production process of the positive electrode active material, the non-aqueous electrolyte of Example 28 was prepared in the same manner as in Example 1 except that the electrode was designed so that the charging voltage was 4.50 V when the non-aqueous electrolyte battery was produced. An electrolyte battery was produced. For the nonaqueous electrolyte battery of Example 28, the initial capacity and capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charge voltage was 4.50V.

<Example 29>
In the production process of the positive electrode active material, the non-aqueous electrolyte of Example 29 was obtained in the same manner as in Example 1 except that the electrode was designed so that the charging voltage was 4.60 V when the non-aqueous electrolyte battery was produced. An electrolyte battery was produced. For the nonaqueous electrolyte battery of Example 29, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.60 V.

<Example 30>
The non-aqueous electrolyte of Example 30 is the same as Example 1 except that the electrode is designed to have a charging voltage of 4.70 V when the non-aqueous electrolyte battery is produced in the production process of the positive electrode active material. An electrolyte battery was produced. For the nonaqueous electrolyte battery of Example 30, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.70 V.

<Comparative Example 6>
In Comparative Example 1, the nonaqueous electrolyte battery of Comparative Example 6 was prepared in the same manner as Comparative Example 1 except that the electrode was designed so that the charging voltage was 4.20 V when the nonaqueous electrolyte battery was produced. Produced. For the nonaqueous electrolyte battery of Comparative Example 6, the initial capacity and capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.20V.

<Comparative Example 7>
In Comparative Example 1, the nonaqueous electrolyte battery of Comparative Example 7 was prepared in the same manner as Comparative Example 1 except that the electrode was designed so that the charging voltage was 4.25 V when the nonaqueous electrolyte battery was produced. Produced. For the nonaqueous electrolyte battery of Comparative Example 7, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.25V.

<Comparative Example 8>
In Comparative Example 1, the nonaqueous electrolyte battery of Comparative Example 8 was prepared in the same manner as Comparative Example 1 except that the electrode was designed so that the charging voltage was 4.35 V when the nonaqueous electrolyte battery was produced. Produced. For the nonaqueous electrolyte battery of Comparative Example 8, the initial capacity and capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.35V.

<Comparative Example 9>
In Comparative Example 1, the nonaqueous electrolyte battery of Comparative Example 9 was prepared in the same manner as Comparative Example 1, except that the electrode was designed so that the charging voltage was 4.50 V when the nonaqueous electrolyte battery was produced. Produced. For the nonaqueous electrolyte battery of Comparative Example 9, the initial capacity and capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.50 V.

<Comparative Example 10>
In Comparative Example 1, the nonaqueous electrolyte battery of Comparative Example 10 was prepared in the same manner as Comparative Example 1 except that the electrode was designed to have a charging voltage of 4.60 V when the nonaqueous electrolyte battery was produced. Produced. For the nonaqueous electrolyte battery of Comparative Example 10, the initial capacity and capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.60V.

<Comparative Example 11>
In Comparative Example 1, the nonaqueous electrolyte battery of Comparative Example 11 was prepared in the same manner as Comparative Example 1 except that the electrode was designed so that the charging voltage was 4.70 V when the nonaqueous electrolyte battery was produced. Produced. For the nonaqueous electrolyte battery of Comparative Example 11, the initial capacity and the capacity retention rate were measured in the same manner as in Example 1 except that the upper limit charging voltage was 4.70V.

  Table 2 shows the measurement results of the initial capacity and capacity retention rate of Example 1, Example 25 to Example 30, and Comparative Example 1, Comparative Example 5 to Comparative Example 11.

  As shown in Table 2, according to the comparison between Example 1, Example 25 to Example 30, and Comparative Example 1, Comparative Example 6 to Comparative Example 11, at least the above-described positive electrode active material was used, so that the upper limit charging was performed. It was found that, in a nonaqueous electrolyte battery having a voltage of 4.25 V or more and 4.70 V or less, it is possible to suppress deterioration of cycle characteristics that becomes more prominent and to obtain excellent high-temperature cycle characteristics.

  In the lithium transition metal composite oxide particle, fluorine (F) is present in a state in which the fluorine (F) is replaced by a solid solution and does not form a metal fluoride phase, and at least nickel (Ni) and manganese (Mn) are present. A positive electrode that is excessively present on the particle surface as compared to the whole particle, and the elemental composition of the particle surface is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5 It is an active material. A non-aqueous electrolyte battery using this positive electrode active material has excellent characteristics even in a high temperature environment. Moreover, the nonaqueous electrolyte battery using this positive electrode active material can implement | achieve a high energy density by setting an upper limit charging voltage higher than before.

  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, in the above-described embodiment, a cylindrical battery and a laminate battery have been described as examples. However, the present invention is not limited to these, and various shapes such as a square, a coin, and a button can be used. Can do.

  Moreover, in the above-mentioned embodiment, although the example which applied this invention with respect to the battery provided with a non-aqueous electrolyte or gel electrolyte as an electrolyte was shown, it is not limited to these. For example, the present invention may be applied to a battery including a solid electrolyte. As the solid electrolyte, any inorganic solid electrolyte or polymer solid electrolyte can be used as long as the material has lithium ion conductivity. Examples of the inorganic solid electrolyte include lithium nitride and lithium iodide. The polymer solid electrolyte is composed of an electrolyte salt and a polymer compound that dissolves the electrolyte salt. Examples of the polymer compound include ether polymers such as poly (ethylene oxide) and cross-linked polymers, poly (methacrylate) esters, and acrylates. A system or the like may be used alone, or may be copolymerized or mixed in the molecule.

  Furthermore, the manufacturing method of an electrode is not ask | required. For example, a method of applying a known binder or conductive material to the material and adding a solvent, a method of adding a known binder or the like to the material and applying it by heating, a material alone or a conductive material, May be mixed with a binder and subjected to a treatment such as molding to produce a molded body electrode on the current collector, but is not limited thereto. More specifically, for example, the active material can be mixed with a binder, an organic solvent or the like to form a slurry, which is then applied onto a current collector and then dried. Furthermore, regardless of the presence or absence of the binder, it is also possible to produce a strong electrode by performing pressure molding while applying heat to the active material.

  Further, the method for producing the battery is not limited, but for example, a production method in which the separator is wound between the positive and negative electrodes around the core, or a lamination method in which the electrode and the separator are sequentially laminated is employed. The present invention is also effective when adopting a winding method when manufacturing a rectangular battery.

It is sectional drawing showing the structure of the 1st example of the nonaqueous electrolyte battery using the electrolyte by one Embodiment of this invention. It is sectional drawing which expands and represents a part of winding electrode body in the nonaqueous electrolyte battery shown in FIG. It is a disassembled perspective view showing the structure of the 2nd example of the nonaqueous electrolyte battery using the electrolyte by one Embodiment of this invention. It is sectional drawing along the II line | wire of the winding electrode body shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Battery can 12, 13 ... Insulation board 14 ... Battery cover 15 ... Safety valve 15A ... Disc board 16 ... Heat sensitive resistance element 17 ... Sealing gasket 20, 30, ... Winding electrode body 21, 33 ... Positive electrode 21A, 33A ... Positive electrode current collector 21B, 33B ... Positive electrode active material layer 22, 34 ... Negative electrode 22A, 34A ... Negative electrode current collector 22B 34B ... Negative electrode active material layer 23, 35 ... Separator 24 ... Center pin 25, 31 ... Positive electrode lead 26, 32 ... Negative electrode lead 36 ... Electrolyte layer 37 ... Protective tape 40 ... exterior member 41 ... adhesion film

Claims (6)

The lithium transition metal composite oxide particles exist in a form in which fluorine (F) is replaced by solid solution,
Furthermore, at least nickel (Ni) and manganese (Mn) are present in excess on the surface of the particles as compared to the whole particles,
A positive electrode active material, wherein the elemental composition of the surface of the particles is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5. 2. The positive electrode active material according to claim 1, wherein the elemental composition of the entire particle is (Co / “Ni + Mn”)> 2.0. The lithium transition metal composite oxide particles include magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), vanadium (V), gallium (Ga), yttrium (Y), zirconium (Zr), 2. The positive electrode active material according to claim 1, comprising at least one selected from the group consisting of niobium (Nb), molybdenum (Mo), tin (Sn), tungsten (W), and bismuth (Bi). . A positive electrode active material,
The positive electrode active material is
The lithium transition metal composite oxide particles exist in a form in which fluorine (F) is replaced by solid solution,
Furthermore, at least nickel (Ni) and manganese (Mn) are present in excess on the surface of the particles as compared to the whole particles,
A positive electrode characterized in that the elemental composition of the surface of the particles is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5. A positive electrode including a positive electrode active material, a negative electrode, and an electrolyte;
The positive electrode active material is
The lithium transition metal composite oxide particles exist in a form in which fluorine (F) is replaced by solid solution,
Furthermore, at least nickel (Ni) and manganese (Mn) are present in excess on the surface of the particles as compared to the whole particles,
A nonaqueous electrolyte battery, wherein the elemental composition of the surface of the particles is 0.01 ≦ F / O <21 and (Co / “Ni + Mn”) <4.5. 6. The nonaqueous electrolyte battery according to claim 5, wherein the upper limit charging voltage is 4.25V or more and 4.70V or less.

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