WO2010040285A1 - Titanium-containing active material for negative electrodes and its production method and titanium-containing power lithium battery - Google Patents

Abstract

A titanium-containing active material for negative electrodes and its production method, and a titanium-containing power lithium battery. The titanium-containing active material for negative electrodes has a general formula of Li₄Ti₅O₁₂/M_x, wherein Li₄Ti₅O₁₂ is spinel lithium titanate, M is a doping substance selected from a metal element, metal compound, non-metal substance or non-metal compound, and 0<x≤10; an element or ion of said doping substance enters into the lattice matrix of Li₄Ti₅O₁₂ or combines with Li₄Ti₅O₁₂. The production method for the titanium-containing active material includes the following steps: a mixture of a composite lithium titanate precursor is produced and heat treated after spray drying. The titanium-containing power lithium battery uses Li₄Ti₅O₁₂/M_x as an active material for negative electrodes.

Description

 Titanium-based anode active material and preparation method thereof, titanium-based lithium ion power battery, titanium-based anode active material, preparation method thereof, and titanium-based lithium ion power battery

[1] Technical field

 [2] The present invention relates to a lithium ion battery anode material for a power battery, a preparation method thereof, and a lithium ion power battery using the anode material, in particular, a titanium anode material, a preparation method thereof, and the use of the titanium A lithium ion power battery that is a negative electrode material.

 [3] Background Art

 [4] With the steady development of the global economy, the production of automobiles has increased dramatically. The exhaust gas emitted by the fuel car causes atmospheric pollution, and the pollutants in the air are 63%.

 From the car exhaust. Environmental issues, especially the deteriorating air quality, have caused widespread concern in countries around the world, especially in developed countries. Last century 70

 After the outbreak of three global oil crises in the world, various multinational auto companies began to develop various types of electric vehicles. Enter 90

 In the era, with the deepening of the global energy crisis, the depletion of oil resources and the increase of air pollution and rising global temperatures, some western countries, mainly in the United States and Europe, began to formulate and gradually implement strict standards for vehicle exhaust emissions. Governments and auto companies generally recognize that energy conservation and emission reduction are the main directions for future automotive technology development. It is imperative to develop clean vehicles with no emissions or low emissions and low fuel consumption. The development and application of electric vehicles will solve these two problems. The best way to technical difficulties, low-energy, pollution-free green cars have begun to become a hot spot of concern.

[5] Currently used and developed power batteries for electric vehicles mainly include: lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries, lithium-ion batteries and fuel cells. Lithium-ion battery is a kind in the 20th century 90

 The most advanced rechargeable battery ever developed in the early years. Lithium-ion batteries have a high operating voltage of 3.6V and high energy density, which is 3 times and 1.5 times that of Cd/Ni and MH/Ni batteries, respectively.

Times, self-discharge is small, less than 8% / month, long life and no memory effect, the advantages of environmental friendliness, most likely to meet the requirements of electric vehicles. Since Sony introduced lithium-ion battery technology to the market in 1991, advances in electrode materials have been driving the continuous development of this technology. Advanced electrode materials have become the current lithium ion. The core technology of battery replacement. The lithium-ion battery of the prior art is used as a power battery for an electric vehicle, and has the following disadvantages: (1) The problem of fast charging is very prominent. After the vehicle is running normally, the discharge rate of the existing lithium ion battery can be fully satisfied, but in the braking In the process, the braking process is short, generally not more than 10s, and the motor needs a large instantaneous current to effectively brake and recover energy. In theory, the vehicle has 50~60% of braking energy that can be recovered, and the actual recovered braking. Energy <20%, the discharge rate of existing lithium-ion batteries, especially the charging rate is difficult to meet the basic requirements of electric vehicles fast charge and fast release. (2) Safety is a key factor for the practical use of lithium-ion batteries in vehicles. Safety issues restrict the development of power batteries. The safety of positive and negative materials for lithium-ion batteries in the prior art is low, mainly for the following four reasons: a. Traditional lithium The anode material of the ion-charged battery is LiCo0 ₂ , the graphite is the anode material, and the cathode material is 150.

 ^The left and right will resolve the oxygen and react with the electrolyte, resulting in abnormal heating; b. The insertion potential of lithium ion in the carbon-based material is close to the reduction potential of the metal lithium; c. The large-rate charge and discharge cannot be performed; d. There is no charging end indication on the curve, which is not suitable for power batteries for electric vehicles.

As a negative electrode material for lithium ion batteries, non-carbon negative electrode materials have received increasing attention from researchers because of their high energy density and safety performance. Non-carbon material Lithium titanate Li ₄ Ti ₅ 0 ₁₂ has a spinel structure, space group Fd3m, used as a negative electrode material, and has small volume and structure changes during charge and discharge (the volume expansion ratio of graphite is usually about 9%, charge) Repeated changes in the temperature of the discharge 容易, easily lead to damage to the smooth surface, the service life is generally 4 00

It is a zero-strain material, so it has excellent cycle performance. The surface of the lithium titanate negative electrode can make the battery charge up to 20,000 times. The spinel structure is conducive to the insertion and removal of lithium ions. The platform is located near 1.5V (vs. Li/Li÷), which is not easy to cause lithium metal to precipitate, can perform large current charge and discharge, solve the dendrite problem, and the battery unit can avoid thermal runaway. Unlike ordinary graphite, the solid electrolyte interface SEI does not form at the interface between Li ₄ Ti ₅ 0 ₁₂ and the electrolyte.

The film, therefore, does not increase internal resistance. In addition, lithium titanate has obvious charging and discharging platform, and has obvious voltage mutation at the end of charge and discharge, and has good overcharge resistance and over-discharge resistance. Since the internal resistance is low, it can be combined with different electrolytes, so the discharge characteristics at low temperatures are excellent. Spinel lithium titanate is suitable for power supply for electric vehicles, and its theoretical lithium insertion capacity is 175mAh/g.

 The actual specific capacity is between 120~130mAh/g. Lithium titanate is used as a negative electrode material as follows: 1

, low capacity, low bulk density, low compaction density, low volumetric capacity; 2 , large rate performance needs to be improved; 3, poor product consistency and poor battery processing; 4, easy to absorb water, battery is easy to expand.

[7] Summary of the invention

 [8] An object of the present invention is to provide a titanium-based anode active material, a preparation method thereof, and a titanium-based lithium ion power battery, and the technical problem to be solved is to improve the rate performance, safety performance, cycle life and environmental protection of a lithium ion power battery. performance.

[9] The present invention uses the following technical solutions:

A titanium-based negative electrode active material having a general formula of Li ₄ Ti ₅ 0 ₁₂ /M _x , wherein: 0

Is a spinel lithium titanate, M is a miscellaneous substance metal element, a metal compound, a non-metal elemental or a non-metal compound, and the element or ion contained in the catastrophic substance enters the lattice of the ^1 ₅ 0 ₁₂ lattice or The titanium-based negative electrode active material Li ₄ Ti ₅ 0 ₁₂ /M _x has an average particle diameter of 0.1 to 30 μm _; the metal element is Al, Mg, Cu, Ag,

 Ni, Cos Mn, Cd, Pb, Bis Sn or Ge, metal compounds are alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide , tin oxide, aluminum fluoride, lithium fluoride or magnesium fluoride, non-metal element is boron, carbon, silicon, phosphorus or iodine, non-metallic compounds are furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy Resin, polyvinyl alcohol, polymethyl methacrylate, polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum pitch.

[10] The Li ₄ Ti ₅ 0 ₁₂ /M _x substrate of the present invention is coated with a coating layer of a nano-cladding material, and the nano-cladding material is nano titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide, Silver oxide, tin oxide, acetylene black or nano-carbon material, the thickness of the coating layer is between 5 and 50 nm.

 [11] A method for preparing a titanium-based anode active material, comprising the following steps: 1. Lithium in an inorganic lithium salt: Titanium dioxide: molar modifier molar ratio 1.9~2.1: 4.9-5.1: greater than 0~10

 Mixing a composite lithium titanate precursor mixture; the inorganic lithium salt is

Lithium hydroxide, lithium carbonate, lithium acetate, lithium chloride, lithium sulfate, lithium nitrate, lithium iodide, lithium t-butoxide, lithium benzoate, lithium formate, lithium fluoride, lithium chromate, lithium citrate tetrahydrate, Lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate or lithium oxalate The miscellaneous modifier is a metal element, a metal compound, a non-metal elemental or a non-metal compound, and the metal element is Al, Mgs Cu, Ag, Ni, Cos Mn, Cd, Pb, Bi, Sn or Ge, a metal compound Alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride or magnesium fluoride, Non-metallic elements are boron, carbon, silicon, phosphorus or iodine. Non-metallic compounds are furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, polytetrafluoroethylene. Ethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum asphalt; 2. Disperse the mixture in an organic solvent at a mass ratio of 1 to 1.5:1, at 100 to 350 ° C Spray-drying and granulating to obtain a dispersed powder; 3. Dissolving the dispersed powder at a temperature rising rate of l~15 ° C / min, heat-treating 4 to 40 hours in a temperature range of 500 to 950 ° C, and naturally cooling to 150 °C

 The titanium-based negative electrode active material is obtained below.

[12] The method of the present invention is based on lithium in an inorganic lithium salt: Titanium dioxide: miscellaneous modifier: nano-cladding material molar ratio 1.9 2.1: 4.9-5.1: greater than 0~10

 : Composite lithium titanate precursor mixture prepared by mixing more than 0~4.0; nano-cladding material is nano titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide, silver oxide, tin oxide, acetylene black or nano carbon material

[13] The method of the present invention is cooled and sieved and sieved to obtain a particle size of 0.1 to 30 μm.

 Titanium-based negative electrode active material.

[14] The method of the present invention uses a high-speed stirring or ball milling method, and the rotation speed is 100~500r/min.

 , grinding and dispersion 2~40 hours.

[15] Process of the Invention The organic solvent is ethanol or acetone.

[16] The process of the invention is conducted with argon or nitrogen during the heat treatment.

[17] A titanium-based lithium ion power battery having a positive electrode and a negative electrode, the negative electrode being composed of Li ₄ Ti ₅ 0 ₁₂ /M _x , a conductive agent, and a binder dissolved in N-methylpyrrolidone, quality The ratio is 85~95%: 3~10%: 2~10%, where: 0

Is a spinel lithium titanate, M is a heterogeneous metal element, a metal compound, a non-metal elemental or a non-metal compound, and the elements or ions contained in the catastrophic substance enter Li ₄ Ti ₅ 0 ₁₂ Lattice lattice or composite with it, the average particle size is 0.1~30μηι _; the metal element is

 Al, Mgs Cu, Ag, Ni, Cos Mn, Cd, Pb, Bi, Sn or Ge, metal compounds are alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide , manganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride or magnesium fluoride, non-metal element is boron, carbon, silicon, phosphorus or iodine, non-metallic compounds are furfural resin, urea-formaldehyde resin, dense More than one type of amine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum pitch.

[18] The Li ₄ Ti ₅ 0 ₁₂ /M _x substrate of the battery of the invention is coated with a coating layer of a nano-cladding material, and the nano-cladding material is nano titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide. , silver oxide, tin oxide, acetylene black or nano-carbon material, the thickness of the coating layer is between 5 and 50 nm.

 [19] The positive electrode of the battery of the invention is composed of an iron-based or manganese-based active material, a conductive agent and a binder dissolved in N-methylpyrrolidone, and the mass ratio is 85 to 95%: 3 to 10%: 2~ 10%.

[20] The iron-based active material of the battery of the present invention is 1^^0 ₄ or ^ ₂ ^ 0 ₄ , and the manganese-based active material is LiMnP0 ₄ , LiCo _x Ni _y Mn ₍₁ . _x . _y) 0 _{2 )} wherein 0 ≤ χ<1, 0<y<l, Li[Li _x Mn ₍₂ . _x) ]0 _{4 )} where 0≤

χ<1/3 , Li[M _x Mn ₍₂ . _x) ]0 _{4 )} where 0<χ<1, M is a 3d transition metal element, Li ₂ MnSi0 ₄ .

 [21] The iron-based and manganese-based active material of the battery of the present invention has an average particle diameter of 0.1 to 30 μm.

[22] Compared with the prior art, the elements or ions of the impurity substance enter the lattice, complex or surface of the Li ₄ Ti ₅ 0 ₁₂ lattice, and the titanium-based anode active material has high capacity and high bulk density. Titanium-based lithium ion power battery with high compaction density, high volume ratio, high rate performance, good product consistency, good battery processing performance and battery swellability, and low cost, the negative electrode contains titanium active material. The battery has high safety performance, rate performance, cycle performance, and the method for manufacturing the battery of the invention is simple and low-cost; the battery is environmentally friendly, has no leakage, has long storage life, is easy to be miniaturized, and has a wide temperature range, and can be used as each Power battery.

 [23] BRIEF DESCRIPTION OF THE DRAWINGS

 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an SEM image of a negative electrode active material obtained in Example 1 of the present invention.

 Fig. 2 is a graph showing the discharge of a battery cell of Example 1 of the present invention.

 Fig. 3 is a cycle diagram of a battery cell of Embodiment 1 of the present invention.

4 is a discharge graph of the lithium iron phosphate/MCMB power battery of Comparative Example 1. 5 is a cycle performance diagram of the lithium iron phosphate/MCMB power battery of Comparative Example 1.

Fig. 6 is a TEM image of the negative electrode active material obtained in Example 1.

Fig. 7 is an XRD diffraction pattern of the negative electrode active material obtained in Example 1.

Figure 8 is an XRD diffraction pattern of a lithium titanate substrate of Comparative Example 1.

[32] Specific implementation

The invention will be further described in detail below with reference to the drawings and embodiments. The titanium-based negative electrode active material of the present invention has a general formula of Li ₄ Ti ₅ 0 ₁₂ /M _x , wherein: 0<x≤10, and Li ₄ Ti ₅ 0 ₁₂ is a spinel lithium titanate.

 M is a monolithic metal elemental Al, Mgs Cu, Ag, Ni, Co, Mn, Cd, Pb, Bi, Sn or Ge

, metal compound alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride or fluorination Magnesium, non-metallic elemental boron, carbon, silicon, phosphorus or iodine, non-metallic compound furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, polytetrafluoroethylene Ethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum pitch. The element or ion contained in it is or complexed with a lattice of ₄ 13⁄40 ₁₂ lattice, and the average particle size is 0.1~ 30μηι. The Li4Ti ₅ 0 ₁₂ /M _x substrate may also be coated with a cladding layer of nano-cladding material, such as nano titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide, silver oxide, tin oxide, For acetylene black or nano-carbon materials, the thickness of the coating layer is between 5 and 50 nm.

[34] Spinel lithium titanate Li ₄ Ti ₅ 0 ₁₂ is a composite oxide of metallic lithium and low-potential transition metal titanium, belonging to the AB ₂ X ₄ series, whose crystal structure is similar to that of spinel LiMn ₂ 0 ₄ It can be written as Li[Li _{1/ 3} Ti _{5/ 3} ]0 ₄ , and the space group is Fd3m, which has a three-dimensional diffusion channel of lithium ions. Wherein, 02- is located at 32e, which constitutes the FCC lattice, part of Li+ is located at the tetrahedron 8a, and the remaining Li+ and Ή4+ are 1:5.

The proportions are randomly distributed in the 16d position of the octahedron. Therefore, it can be described as Li _8a [Li _1/3 Ti _5/3 ] _16d according to the structure.

[0 4] 32e

 . Spinel-type lithium titanate has no volume strain during charging and discharging, and has a long service life because its discharge potential is 1.55 V (vs. Li/Li+) flat and does not react with the electrolyte.

[35] A method for preparing a titanium-based negative electrode active material of the present invention, comprising the steps of:

[36] First, according to lithium in inorganic lithium salt: Titanium dioxide: Miscellaneous modifier molar ratio 1.9~2.1: 4.9-5.1: After mixing more than 0~10, use high-speed stirring or ball milling method, speed 100~500 r/min, grinding and dispersing 2~40 hours to produce a composite lithium titanate precursor mixture, ie! ^! ! a mixture of ^^ and ^^, the inorganic lithium salt is lithium hydroxide, lithium carbonate, lithium acetate, lithium chloride, lithium sulfate, lithium nitrate, lithium iodide, lithium t-butoxide, lithium benzoate, lithium formate, fluorination Lithium, lithium chromate, lithium citrate tetrahydrate, lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate or lithium oxalate, miscellaneous modifiers are metal elements Al, Mg, Cu, Ag, Ni, Cos Mn, Cd , Pb, Bi, Sn,

 Ge, metal compound alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride, fluorine Magnesium, non-metallic elemental boron, carbon, silicon, phosphorus, iodine and non-metallic compounds furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, polytetra More than one type of vinyl fluoride, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum asphalt, used by QM-1SP4 of Nanjing University Instrument Factory

Planetary ball mill, the same can be added with lithium: Titanium dioxide: the ratio of the amount of miscellaneous modifier substances is greater than 0-4.0

Nano-clad material, nano-cladding material is nano-titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide, silver oxide, tin oxide, acetylene black or nano carbon material; 2. Dispersing the above mixture in organic solvent ethanol Or acetone, the mass ratio of solid to organic solvent is 1~1.5: 1

, using a spray drying method to obtain a dispersed powder,

In the DFZR centrifugal spray granulation dryer of Wuxi Dafeng Drying Equipment Co., Ltd., spray-drying and granulating at 100-350 °C to obtain a dispersed powder; 3. Dispersing the powder at l~15 °C/ Temperature rise rate of min, heat treatment 4~40 in the temperature range of 500~950 °C

After the enthalpy, argon or nitrogen is used as a shielding gas, so that the elements or ions contained in the catastrophic modifier enter the Li ₄ Ti ₅ 0 ₁₂ lattice lattice, compound, and naturally cool to 150 ° C.

Hereinafter, the pulverization and sieving are carried out to obtain a titanium-based negative electrode active material having a particle size of 0.1 to 30 μm. For example, C uO, Mgs Al, F, C are miscellaneous modifiers, and finally the composition expression is Li ₄ Ti ₅ 0 ₁₂ /CuO _ai ( x=0.1 ) , Li ₄ Ti ₅ 0 ₁₂ /Al _a2 (x =0.2) , Li ₄ Ti ₅ 0 ₁₂ /Mgo.3 (χ=0·3) , Li ₄ Ti ₅ O ₁₂ /F ₀₀₅ (x=0.05) , Li ₄ Ti ₅ O ₁₂ /C ₁₀ (x=10 Titanium-based anode active material.

表面Use the KYKY-2800B scanning electron microscope of Beijing Zhongke Science and Technology Development Co., Ltd. to observe the surface morphology of the material particles prepared by the method of the invention, and use the Dutch PANalytical The company's X'Pert PRO diffractometer and Japan JEOL 2010 transmission electron microscope

It is known that miscellaneous elements or ions enter the Li ₄ Ti ₅ 0 ₁₂ lattice lattice and/or complex.

[38] The titanium-based negative electrode active material of the present invention is miserable in the preparation process, and the miscellaneous substance mainly replaces the six-coordinated 16d in Lip^ ₃ Ti _{5/ 3} ]0 ₄

A part of the material of the site or dispersion coating, no diffraction peak of the disinquisite in the XRD pattern of the spinel lithium titanate Li ₄ Ti ₅ 0 ₁₂ matrix, indicating that the miscellaneous atoms entered the lithium titanate ^1 _{In the 5} 0 ₁₂ lattice, elements or ions in the impurity matter enter Li ₄ Ti ₅ 0 ₁₂

 Under the action of lattice lattice, composite or surface coating, the material has high capacity, good consistency, good stability, good processing performance, high compaction density of the pole piece, and the battery made of the material as the negative electrode active material. Good rate performance, high energy density, high power density, good high and low temperature performance, and good safety performance.

[39] The titanium-based lithium ion power battery of the present invention, the negative electrode is composed of Li ₄ Ti ₅ 0 ₁₂ /M _x , a conductive agent and a binder dissolved in N-methylpyrrolidone, and the mass ratio is 85 to 95%. : 3~ 10%: 2~ 10%, where: 0<x≤ 10. The positive electrode is an iron-based or manganese-based active material, a conductive agent, and is dissolved in N-methylpyrrolidone.

 The binder composition has a mass ratio of 85 to 95%: 3 to 10%: 2 to 10%. Fe

Active cathode material: LiFeP0 ₄ or Li ₂ FeSi0 ₄ , Mn active cathode material: LiMnP0 ₄ , LiCo _x Ni _y Mn ₍₁ . _x . _y) 0 2 (0<χ<1,0<y<l), Li[Li _x Mn ₍₂ . _x) ]0 ₄ (0≤ x<l/3) , Li[M _x Mn ₍₂ . _x) ]0 ₄ (0<χ<1, M is a 3d transition metal element) , Li ₂ MnSi0 ₄ .

 The average particle size of the Fe-based and Mn-based active cathode materials is 0.1~30μηι

. The conductive agent is one or more of conductive materials of acetylene black, conductive graphite, carbon nanotubes or nano carbon fibers, and the binder is polyvinylidene fluoride PVDF or polytetrafluoroethylene. The electrolyte is an electrolyte containing LiPF ₆ , LiC10 ₄ or LiAsF ₆ l mol/L, and the organic solvent is ethylene carbonate EC

 , propylene carbonate PC, dimethyl carbonate DMC, diethyl carbonate DEC

 , dimethyl ether DME and methyl ethyl carbonate one or more of EMC

 Mixed organic solvents. Copper foil and aluminum foil are the current collectors of the negative electrode and the positive electrode, respectively.

 The polypropylene film, the polyethylene film or the copolymer film of propylene and ethylene is a separator, and the plastic, metal or alloy is a battery case.

[40] The method for producing a titanium-based lithium ion power battery of the present invention: Li ₄ Ti ₅ 0 ₁₂ /M _x , a conductive agent and a binder dissolved in N-methylpyrrolidone are placed in Guangzhou Hongyun Machinery Factory In the DLH2 power mixer, to 150 After stirring for 12 minutes, the desired negative electrode slurry was obtained. The negative electrode slurry was placed on a slurry machine, coated on a 20 μm copper foil, and baked at 130 ° C for 6 hours, at 10 MPa.

The roll was pressed under pressure and cut to a size of 270 mm x 42.5 mm to prepare a negative electrode tab having an areal density of 230 g / cm ² and a compact density of 2.1 g / cm 3 . LiFeP0 ₄ having an average particle diameter of 2 μm

 The conductive agent and the binder dissolved in N-methylpyrrolidone were placed in the DLH2 power mixer produced by Guangzhou Hongyun Machinery Factory.

Stir at a stirring speed of 12 minutes. The positive electrode slurry was placed on a slurry machine, coated on an aluminum foil of 20 μm, baked at 150 ° C for 6 hours, rolled at a pressure of 25 MPa, and sheared at a size of 320 mm x 41.5 mm to prepare an areal density. 210g /cm ²

 Positive pole piece. The positive electrode piece, the separator and the negative electrode piece are stacked in order, in 423048 of Shaoyang Dali Power Industry Co., Ltd.

 The winder is wound on a winder and placed in a casing after hot pressing. Put the battery unit in the DZF-6050 hollow baking box produced by Shanghai Medical Equipment Factory, at 80

After baking at room temperature for 24 hours, the battery cells were transferred to the injection chamber, and the electrolyte of 1 mol/L LiPF _{6 was} injected. After sealing, the battery cells were fabricated.

 According to the required voltage and current, the battery cells are assembled into a power battery by combining parallel and series.

 [41] Place the prepared battery cell for 12 hours, put it on the battery into a cabinet, charge current 1.0C, charge to 3.0V

 The constant voltage is charged until the current is 0.01 C, and then the constant current discharge is performed at a discharge rate of 1.0 C, and the discharge cutoff voltage is 1.0 V, and the charge and discharge are repeated twice. Test the internal resistance, capacity, and battery data of the battery cells with the BS-8303Q battery test system of Guangzhou Qingtian Industrial Co., Ltd., and test the charge and discharge curves and cycle performance of the battery cells. The test conditions are as follows: Charging current multiplier 1.0C, charged to 3.0V

 , perform constant voltage charging until the current is 0.01C, to 1.0C

 The discharge rate is constant current discharge, and the discharge cutoff voltage is 1.0V.

[42] Example 1 : 2 mol of lithium carbonate, 5 mol of titanium dioxide, 0.1 mol of

 Nano-sized copper oxide powder, nano carbon 4mol, rotation speed 300 r/min

, a composite lithium titanate precursor mixture prepared by grinding and dispersing 16 hours; dispersing the composite lithium titanate precursor mixture In ethanol, the ratio of solid to organic solvent is 1.5: 1, to 150

 Spray drying to obtain a dispersed powder at °C; dispersing the powder at 5 ° C / min

 The heating rate is heat-treated at a temperature of 700 ° C for 24 hours, during which nitrogen gas is introduced and naturally cooled to below 150 ° C; pulverization and sieving are carried out to obtain I^TisC CuC^ (x) having an average particle size of ΙΟμηι =0.l) Negative active material. As shown in Fig. 1, the lithium titanate material has spherical and spheroidal microscopic features, and the surface is smooth. As shown in Fig. 6, the thickness of the nano-cladding layer is about 8 nm, and the coating layer is uniform, as shown in Fig. 7, XRD. The figure shows that there is no peak containing copper in the spectrum, indicating that the impurity enters the crystal lattice of the spinel lithium titanate, the coating is amorphous carbon and the carbon content is low, on the XRD pattern. Display is not obvious

[43] The negative electrode active material, the conductive agent acetylene black and the binder PVDF obtained above are in a mass ratio of 90

%: 5%: 5% of the negative electrode pieces. LiFeP0 ₄ , conductive agent acetylene black and binder PVDF, by mass ratio of 90%: 5 %: 5

% Make a positive pole piece. The positive electrode tab, the Celg _a rd2400 polypropylene separator and the negative electrode tab are stacked in this order, wound, hot pressed, and then placed in a plastic case. After baking, a 1 mol/L electrolyte is injected into LiPF ₆ , solvent EC+ The electrolyte with a DMC volume ratio of 1:1 is prepared as a power battery cell after sealing.

[44] The prepared power battery cells were tested and formed. The test results are shown in Table 1. Figure 2

 Shown, 5C

 The discharge capacity of the discharge rate is 2.0Ah, and the capacity is still l.lAh under the condition of discharge rate of 30C. As shown in Fig. 3, under the condition of 10C discharge rate, the cycle performance of the battery is very good, and the capacity retention rate of 2000 weeks is 98.1.

%.

 [45] Example 2

 : 2.1 mol of lithium carbonate, 5.1 mol of titanium dioxide, 0.1 mol of nano-sized alumina powder, rotating speed 200 r/min

 , grinding and dispersing 24 hours to prepare a composite lithium titanate precursor mixture; dispersing the composite lithium titanate precursor mixture in ethanol, the ratio of solid to organic solvent is 1.5: 1, to 250 ° C

Under the condition of spray drying to obtain a dispersed powder; the dispersion powder is heat-treated at a temperature rising rate of 10 ° C / min, in a temperature range of 400 ° C for 40 hours, during which nitrogen is introduced, and naturally cooled to below 150 ° C; The mixture was pulverized and sieved to obtain a Li ₄ Ti ₅ 0 ₁₂ /(A1 ₂ 0 ₃ ) oi (x = 0.1) negative electrode active material having an average particle size of Ιμηι. [46] The negative active material obtained above, the conductive agent acetylene black and the binder PVDF

, The negative electrode piece is made according to the mass ratio of 85%: 10%: 5%. LiFeP0 ₄

 , conductive agent acetylene black and binder PVDF, by mass ratio of 90

%: 4%: 6% of the positive electrode pieces. The positive electrode tab, the Celg _a rd2400 polypropylene separator and the negative electrode tab are stacked in this order, wound and hot pressed, and then placed in a plastic outer casing. After baking, a l mol/L electrolyte is injected into LiPF ₆ , solvent EC+ The electrolyte with a DMC volume ratio of 1:1 is prepared as a power battery cell after sealing.

 [47] The prepared power battery cells were tested and formed. The test results are shown in Table 1.

 [48] Example 3, 2.0 mol

 Lithium carbonate, 4.95mol of titanium dioxide, O.lmol of nano-sized alumina powder, 2mol of acetylene black, rotating at 100 r/min, grinding and dispersing for 24 hours to prepare a composite lithium titanate precursor mixture; dispersing the composite lithium titanate precursor mixture In ethanol, the ratio of solid to organic solvent is 1.0:1 to 350. Spray drying under C conditions to obtain a dispersed powder;

The heating rate of 15 ° C / min, heat treatment 4 吋 in the temperature range of 950 ° C, during the passage of nitrogen, naturally cooled to below 150 ° C; pulverization and sieving, to obtain Li4Ti ₅ 0 ₁₂ with a particle size of Ιμηι / (Α1 ₂ 0 ₃ ) ₀ .ι (x=0.l) Negative active material.

[49] The negative electrode active material, the conductive agent acetylene black, and the binder PVDF obtained above were prepared to have a negative electrode tab at a mass ratio of 95%: 3 %: 2%. LiFeP0 ₄

 , conductive agent acetylene black and binder PVDF, by mass ratio of 95%: 3

%: 2% to make a positive electrode piece. The positive electrode tab, the Celg _a rd2400 polypropylene separator and the negative electrode tab are stacked in this order, wound, hot pressed, and then placed in a plastic case. After baking, a lmol/L electrolyte is injected into Li PF ₆ , solvent EC+ The electrolyte with a DMC volume ratio of 1:1 is prepared as a power battery cell after sealing.

 [50] The prepared power battery cells were tested and formed. The test results are shown in Table 1.

 [51] Example 4, 1.9 mol of lithium carbonate, 4.9 mol of titanium dioxide, 0.1 mol of

 Nano-sized zirconia powder, 0.4 mol nano-carbon, speed 500 r/min

 , grinding and dispersing 2 hours to prepare a composite lithium titanate precursor mixture; dispersing the composite lithium titanate precursor mixture in ethanol, the volume ratio of solid to organic solvent is 1.2: 1, to 350

^: spray drying to obtain a dispersed powder; dispersing the powder at 10 ° C The heating rate of /min is heat-treated at a temperature of 700 ° C for 24 hours, during which nitrogen gas is introduced and naturally cooled to below 150 ° C; pulverization and sieving are carried out to obtain Li4Ti ₅ 0 ₁₂ / (Zr0) having a particle size of Ιμηι ₂ ) ₀ .

 (x = 0.1) A negative active material.

 [52] The negative electrode active material, the conductive agent acetylene black and the binder PVDF obtained above are in a mass ratio of 85

%: 5 %: 10% to make a negative pole piece. LiFeP0 ₄

 , conductive agent acetylene black and binder PVDF, by mass ratio of 90

%: 5%: 5% of the positive electrode pieces. The positive electrode tab, the Celg _a rd2400 polypropylene separator and the negative electrode tab are stacked in this order, wound, hot pressed, and then placed in a plastic outer casing. After baking, a lmol/L electrolyte is injected into LiPF ₆ , solvent EC + DMC An electrolyte with a volume ratio of 1:1, after sealing

 Prepared into a power battery unit.

 [53] The prepared power battery cells were tested and tested. The test results are shown in Table 1.

 [54] Example 5, 2.0 mol of lithium carbonate, 5 mol of titanium dioxide, 0.1 mol of

 The nano-scale aluminum fluoride powder, rotating at a speed of lOOr/min, grinding and dispersing for 40 hours to prepare a composite lithium titanate precursor mixture; dispersing the composite lithium titanate precursor mixture in ethanol, the ratio of solid to organic solvent is 1.3:1 , spray drying at 100 ° C to obtain a dispersed powder; the dispersed powder at 8 ° C / min

The heating rate is heat-treated in a temperature range of 600 ° C for 30 hours, during which argon gas is introduced and naturally cooled to below 150 ° C; pulverization and sieving are carried out to obtain Li ₄ Ti ₅ 0 ₁₂ / with a particle size of Ιμηι / (A1F ₃ ) _αι

 (x = 0.1) A negative active material.

[55] The negative electrode active material, the conductive agent acetylene black, and the binder PVDF obtained above were produced in a mass ratio of 85%: 5 %: 10% to prepare a negative electrode tab. LiFeP0 ₄ , conductive agent acetylene black and binder PVDF, by mass ratio of 95

%: 3%: 2% to make a positive electrode piece. The positive electrode tab, the Celg _a rd2400 polypropylene separator and the negative electrode tab are stacked in this order, wound and hot pressed, and then placed in a plastic outer casing. After baking, a l mol/L electrolyte is injected into LiPF ₆ , solvent EC+ DMC volume ratio of 1: 1 electrolyte, after sealing

 Prepared into a power battery unit.

 [56] The prepared power battery cells were tested and formed. The test results are shown in Table 1.

 [57] Example 6, will be 2.0mol

Lithium carbonate, 5 mol of titanium dioxide, lOmol of nano-sized alumina powder, rotating speed lOOr/min, grinding dispersion 4 0:1,100. The ratio of the ratio of the solid to the organic solvent is 1. _5: 1, to 100, the ratio of the ratio of the solid to the organic solvent is 1.

 Spray-dried at °C to obtain a dispersed powder; the dispersed powder was 8 ° C / min

The heating rate is heat-treated in a temperature range of 600 ° C for 30 hours, during which argon gas is introduced and naturally cooled to below 150 ° C; pulverization and sieving are carried out to obtain Li ₄ Ti ₅ 0 ₁₂ / with a particle size of Ιμηι / (A1 ₂ 0 ₃ ) ₁₀

 (x=10) Negative electrode active material.

 [58] The negative active material obtained above, the conductive agent acetylene black and the binder PVDF

, The negative electrode piece is made by mass ratio of 85%: 5 %: 10%. LiFeP0 ₄

 , conductive agent acetylene black and binder PVDF, by mass ratio of 85 %: 10

%: 5% of the positive electrode pieces. The positive electrode tab, the Celg _a rd 2400 polypropylene separator and the negative electrode tab are stacked in this order, wound, hot pressed, and then placed in a plastic case, and then baked and then injected with 1 mol/L.

The electrolyte is LiPF ₆ and the solvent EC + DMC volume ratio is 1: 1

 The electrolyte is prepared as a power battery unit after sealing.

[59] The prepared power battery cells were tested and formed. The test results are shown in Table 1.

[60] Example 7, 2.0 mol

 Lithium carbonate, 5 mol of titanium dioxide, 0.1 mol of nano-scale aluminum fluoride powder, rotating speed lOOr/min, grinding dispersion

The ratio of the ratio of the solid to the organic solvent is 1. _3: 1, to 100, the composite of the lithium titanate precursor mixture;

 Spray-drying at °C to obtain a dispersed powder; the dispersed powder was heat-treated at a heating rate of 1 °C /min for 30 hours at a temperature of 500 °C, during which argon gas was introduced and naturally cooled to 150 °C.

Below C °; pulverization and sieving to obtain Li ₄ Ti ₅ 0 ₁₂ / (A1F ₃ ) ₀ having a particle size of Ιμηι,

 (x = 0.1) A negative active material.

 [61] The negative electrode active material, the conductive agent acetylene black and the binder PVDF obtained above are in a mass ratio of 85

%: 5%: 10% to make a negative pole piece. LiFeP0 ₄

The conductive agent acetylene black and the binder PVDF were prepared to have a positive electrode tab at a mass ratio of 85%: 5%: 10%. The positive electrode tab, the Celg _a rd2400 polypropylene separator and the negative electrode tab are stacked in this order, wound, hot pressed, and then placed in a plastic outer casing. After baking, a lmol/L electrolyte is injected into LiPF ₆ , solvent EC + DMC The electrolyte with a volume ratio of 1:1 is prepared as a power battery unit after sealing. [62] The prepared power battery cells were tested and formed. The test results are shown in Table 1.

 [63] Comparative Example 1, 2.0 mol of lithium carbonate, 5 mol of titanium dioxide, rotating at 300 r/min, grinding and dispersing 24

O. The ratio of the solid to the organic solvent is 1. _5: 1, by the ratio of the ratio of the solid to the organic solvent.

 Spray drying at 150 ° C to obtain a dispersed powder; dispersing the powder at 10 ° C

The heating rate of /min was heat-treated at a temperature of 700 ° C for 30 hours, during which nitrogen gas was introduced, and it was naturally cooled to 150 ° C or less; pulverization and sieving were carried out to obtain a _{40 12} negative electrode active material having a particle size of Ιμηι. As shown in Fig. 8, in addition to the diffraction peak of the spinel type lithium titanate, there are no other diffraction peaks, and the intensity of the diffraction peak is high.

 [64] The negative electrode active material, the conductive agent acetylene black and the binder PVDF obtained above are in a mass ratio of 85

%: 5%: 10% to make a negative pole piece. LiFeP0 ₄

The conductive agent acetylene black and the binder PVDF were prepared in a mass ratio of 95%: 3%: 2% to prepare a positive electrode tab. The positive electrode tab, the Celg _a rd 2400 polypropylene separator and the negative electrode tab are stacked in this order, wound, hot pressed and placed in a plastic case, and then baked to inject 1 mol/L electrolyte into LiPF ₆

 Solvent EC+DMC The electrolyte solution with a volume ratio of 1:1 is prepared as a power battery unit after sealing.

 [65] After the prepared power battery unit is formed into a test, the test results are shown in Table 1.

 . The cycle performance is shown in Figure 5, with a capacity retention rate of 92% for 1500 weeks.

 [66] Comparative Example 2, using commercially available lithium iron phosphate as a positive electrode active material, MCMB

 As a negative active material, it is assembled into a lithium iron phosphate/MCMB lithium ion power battery according to a mature process. Test conditions: The upper and lower limit voltages are 2.5-4.1V, and the current is charged and discharged 3 times with a current of 0.1C. The discharge curves of different magnifications are shown in Fig. 4. Under the condition of 0.2C discharge rate, the discharge capacity is 487mAh.

 The discharge rate of 50C is about 360mAh.

 [67] The prepared power battery cells were tested and formed. The test results are shown in Table 1. The cycle performance is shown in Figure 5. The 500-week capacity retention rate is 88%.

[68] Table 1 Example and Comparative Power Cell Test Results

 [70] From Table 1

 It can be seen that the lithium titanate prepared by the miscellaneous modification is significantly improved in the rate performance of the battery compared with the comparative example of the lithium titanate prepared by the unmodified modification, and the lithium titanate prepared by the miscellaneous modification is prepared. It is an excellent active material.

 [71] In the examples, the inorganic lithium salt only lists lithium carbonate, lithium carbonate and

 Lithium hydroxide, lithium carbonate, lithium acetate, lithium chloride, lithium sulfate, lithium nitrate, lithium iodide, lithium t-butoxide, lithium benzoate, lithium formate, lithium fluoride, lithium chromate, lithium citrate tetrahydrate, Lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate and lithium oxalate are lithium-containing compounds obtained in

 The composite lithium titanate precursor mixture has the property of thermal decomposition and titanium dioxide reaction, so lithium hydroxide, lithium carbonate, lithium acetate, lithium chloride, lithium sulfate, lithium nitrate, lithium iodide, lithium t-butoxide, benzoic acid Lithium, lithium formate, lithium fluoride, lithium chromate, lithium citrate tetrahydrate, lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate and lithium oxalate are all suitable for use in the process of the invention.

[72] In an embodiment, The miscellaneous modifiers only list alumina, zirconia, copper oxide and aluminum fluoride, aluminum oxide, zirconium oxide, copper oxide, aluminum fluoride and metal elemental Al, Mgs Cu, Ag, Ni, Cos Mn, Cd, Pb, Bi, Sn,

Ge, metal compound magnesium oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, manganese trioxide, lead oxide, tin oxide, lithium fluoride, magnesium fluoride, non-metallic elemental boron, carbon, silicon, phosphorus , iodine and non-metallic compounds furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose , glucose, coal tar pitch or petroleum bitumen, all of which are carbon-containing compounds,

The composite lithium titanate precursor mixture is decomposed into amorphous carbon in the process, and the elements or ions contained therein enter or merge with the Li ₄ Ti ₅ 0 ₁₂ lattice lattice, thereby improving the electrochemical performance of the material.

 Metal elemental Al, Mgs Cu, Ag, Ni, Cos Mn, Cd, Pb, Bi, Sn, Ge, metal compound magnesium oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide , tin oxide, lithium fluoride, magnesium fluoride, non-metallic elemental boron, carbon, silicon, phosphorus, iodine and non-metallic compounds furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, The method of the present invention is applicable to polymethyl methacrylate, polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum pitch.

[73] In the embodiment, the nano-cladding material only lists acetylene black, nano carbon, acetylene black, nano carbon and nano titanium dioxide, aluminum oxide, magnesium oxide, and zirconium oxide are ionic conductors, and the material can be added after forming a coating layer. The conductivity, improve the rate performance. Cuprous oxide, silver oxide, tin oxide

 Forming a cladding layer can change the electrode potential of lithium titanate, thus

 The present invention is applicable to nano titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide, silver oxide, and tin oxide.

 [74] The titanium-based lithium ion power battery of the present invention has the necessary characteristics of a next-generation lithium ion battery, and has a higher number of times of charging and a faster charging process, and lithium titanate is used as a negative electrode material of a lithium ion battery to improve the rapid charging of the system. Discharge and cycle performance, obvious charge and discharge curve of charge and discharge curve, improved safety performance, suitable for power supply of electric vehicles.

[75] The battery of the invention has high safety performance, good rate performance, long cycle life and high weight ratio energy, and is simple in manufacture and low in cost, and can replace the lead-acid battery which is widely used at present. High-energy, high-power, power supply with good rate performance and cycle performance to replace the traditional Lead acid battery. At the same time, the novel battery of the present invention is environmentally friendly and is a green battery. Moreover, the battery of the present invention has advantages such as no leakage, long storage life, and ease of miniaturization, and has a wide temperature range of use.

Claims

Claim

 [1] A titanium-based negative electrode active material, wherein the titanium-based negative electrode active material has a general formula of L

Ti ₅ 0 ₁₂ /M _{X )} wherein: 0<x≤10, Li ₄ Ti ₅ 0 ₁₂ is spinel lithium titanate, M

It is a monolithic metal element, a metal compound, a non-metal elemental substance or a non-metal compound, and the element or ion contained in the impurity substance enters or is complexed with the lattice of the ^1 ₅ 0 ₁₂ lattice; the titanium-based negative electrode active material Li4Ti ₅ 0 ₁₂ /M _x

 The average particle diameter is 0.1~30μηι; the metal element is Al, Mg, Cu, Ag, Ni, Co, Mn, Cd, Pb, Bi, Sn or Ge, and the metal compound is alumina, magnesia, zirconia, Copper oxide

, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride or magnesium fluoride, non-metal elements are boron, carbon, silicon, phosphorus or Iodine, non-metallic compounds are furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose , more than one type of glucose, coal tar pitch or petroleum pitch.

[2] The titanium-based negative electrode active material according to claim 1, wherein the Li4Ti ₅ 0 ₁₂ /M _x substrate is coated with a coating layer of a nano-cladding material, and the nano-cladding material is nano-titanium dioxide. Alumina, magnesia, zirconia, cuprous oxide, silver oxide, tin oxide, acetylene black or nano-carbon material, the thickness of the coating layer is between 5 and 50 nm.

 [3] A method for preparing a titanium-based anode active material, comprising the following steps: 1. According to lithium in an inorganic lithium salt

: Titanium dioxide: molar modifier molar ratio 1.9~2.1: 4.9-5.1: greater than 0~10 mixed lithium titanate precursor mixture; the inorganic lithium salt is

 Lithium hydroxide, lithium carbonate, lithium acetate, lithium chloride, lithium sulfate, lithium nitrate, lithium iodide, lithium t-butoxide, lithium benzoate, lithium formate, lithium fluoride, lithium chromate, lithium citrate tetrahydrate, Lithium tetrachloroaluminate, lithium bromide, lithium tetrafluoroborate or lithium oxalate

 The miscellaneous modifier is a metal element, a metal compound, a non-metal elemental or a non-metal compound, and the metal element is Al, Mg, Cu, Ag, Ni, Co, Mn, Cd, Pb, Bi, Sn or Ge.

The metal compound is alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride or fluorine. Magnesium, non-metal element is boron, carbon, silicon, phosphorus or iodine. Non-metallic compounds are furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, More than one type of polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum pitch; 2. Disperse the mixture in an organic solvent at a mass ratio of 1 to 1.5:1, at 100~350 Spray drying granulation at °C to obtain a dispersed powder; 3. Dissolving the dispersed powder at a temperature rising rate of l~15 °C/min, heat-treating 4~40 hours in a temperature range of 500-950 °C, natural The titanium-based negative electrode active material was obtained by cooling to 150 ° C or lower.

[4] according to claim 3

 The method for preparing a titanium-based negative electrode active material, characterized in that: the lithium in the inorganic lithium salt: titanium dioxide: miscellaneous modifier: nano-cladding material molar ratio 1.9 to 2.1: 4.9-5.1: greater than 0- 10: Greater than 0 4.0

 Mixing a composite lithium titanate precursor mixture; the nano-cladding material is nano-titanium dioxide, aluminum oxide

, magnesium oxide, zirconium oxide, cuprous oxide, silver oxide, tin oxide, acetylene black or nano carbon materials.

[5] according to claim 3 or 4

 In the method for producing a titanium-based negative electrode active material, the film is cooled and sieved to obtain a titanium-based negative electrode active material having a particle size of 0.1 to 30 μm.

[6] according to claim 5

 The method for preparing a titanium-based negative electrode active material is characterized in that: the mixed crucible is subjected to high-speed stirring or ball milling at a rotation speed of 100 to 500 r/min, and is ground and dispersed for 2 to 40 hours.

[7] according to claim 6

 The method for producing a titanium-based negative electrode active material, characterized in that the organic solvent is ethanol or acetone.

 [8] according to claim 7

 The method for producing a titanium-based negative electrode active material, characterized in that argon or nitrogen gas is supplied during the heat treatment.

 [9] A titanium-based lithium ion power battery having a positive electrode and a negative electrode, wherein: the negative electrode is Li4

Ti ₅ 0 ₁₂ /M _x , a conductive agent and a binder dissolved in N-methylpyrrolidone, the mass ratio is 85 to 95%: 3 to 10%: 2 to 10%, wherein: 0 < x ≤ 10, Li ₄ Ti ₅ 0 ₁₂ For spinel lithium titanate, M

a monolithic metal element, a metal compound, a non-metal elemental or a non-metal compound, the element or ion contained in the impurity substance enters or is complexed with a Li4Ti ₅ 0 ₁₂ lattice lattice, and the average particle diameter is 0.1 to 30 μm; The metal element is Al, Mg, Cu, Ag, Ni, Co, Mn, Cd, Pb, Bi, Sn or Ge

 The metal compound is alumina, magnesia, zirconia, copper oxide, cuprous oxide, silver oxide, cobalt oxide, manganese dioxide, dimanganese trioxide, lead oxide, tin oxide, aluminum fluoride, lithium fluoride or fluorine. Magnesium, non-metal element is boron, carbon, silicon, phosphorus or iodine. Non-metallic compounds are furfural resin, urea-formaldehyde resin, melamine resin, phenolic resin, epoxy resin, polyvinyl alcohol, polymethyl methacrylate, More than one type of polytetrafluoroethylene, polyacrylonitrile, styrene butadiene rubber, cellulose, glucose, coal tar pitch or petroleum pitch.

[10] The titanium-based lithium ion power battery according to claim 9, wherein: said Li4Ti ₅ 0 ₁₂

/M _x

 The substrate is coated with a coating layer of nano-cladding material, and the nano-cladding material is nano-titanium dioxide, aluminum oxide, magnesium oxide, zirconium oxide, cuprous oxide, silver oxide, tin oxide, acetylene black or nano carbon material, coated The thickness of the layer is between 5 and 50 nm.

[11] The titanium-based lithium ion power battery according to claim 9 or 10, wherein the positive electrode is an iron-based or manganese-based active material, a conductive agent, and a binder dissolved in N-methylpyrrolidone Composition, mass ratio of 85~95%: 3~10%: 2~10%.

[12] The titanium-based lithium ion power battery according to claim 11, wherein the iron-based active material is LiFeP0 ₄ or Li ₂ FeSi0 ₄ , and the manganese-based active material is LiMnP0 ₄ or LiCo _x Ni _y Mn _{( 1} . _x . _y) 0 ₂

Where 0 ≤ x < l, 0 < y < l , Li [Li _x Mn ₍₂ . _x) ] 0 ₄ , where 0 ≤ χ < 1/3, Li [M _x Mn ₍₂ . _x) ] 0 ₄

Where 0<χ<1, M is a 3d transition metal element, Li ₂ MnSi0 ₄ .

[13] The titanium-based lithium ion power battery according to claim 12, wherein the iron-based and manganese-based active material has an average particle diameter of 0.1 to 30 μm.