253results about How to "High tap density" patented technology

The invention relates to a high-density lithium cobalt oxide power material with a super-large grain diameter. The method comprises the steps of mixing a cobalt compound, a lithium compound or meanwhile a small amount of doping element compounds; sintering for 3 to 30 hours at the high temperature of 950 to 1,100 DEG C to form a block sintered product; crushing and grading the product to obtain the lithium cobalt oxide power material (molecular formula is LiaCo1-bMbO2), wherein, when b is not equal to 0, the middle diameter of the lithium cobalt oxide containing the doping elements is larger than or equal to 15 Mum, and the tap density is higher than or equal to 2.5g/cm<3>; when b is equal to 0, the middle diameter of the lithium cobalt oxide without the doping elements is larger than 20 Mum, and the tap density is higher than or equal to 2.6g/cm<3>. the 3.6V platform capacity rate of the material as the anode active substance for a lithium battery is higher than or equal to 75%; in the thermal impact test in a 150 DEG C thermotank, the lithium battery with the material is free from leakage and does not catch fire or explode for 60 minutes; the 1C5A specific capacity of the material in the battery is larger than or equal to 135mAh/g.

The invention relates to a lithium ion battery cathode material LiNixCoyM1-x-yO2 prepared from micron-sized single crystal particles and a preparation method thereof, wherein x is greater than 0 and is not more than 0.8, y is greater than 0 and is not more than 0.5, and M is one or two of Li, Mn, Al and Mg. The invention is characterized in that (1) composite oxide or hydroxide of transition metal nickel, transition metal cobalt and modified metal M is used as a raw material, the composite oxide or hydroxide is porous aggregate comprising nanocrystals, the average size of the aggregate is 2-50 micrometers, and the specific surface area of the aggregate is greater than 15m<2>/g (measured by BET method); (2) the composite metal oxide or hydroxide and lithium salts are milled in a ball mill, the micron-sized composite metal oxide or hydroxide is converted into nanocrystal particles to obtain a nano-sized mixed precursor of the composite metal oxide or hydroxide and the lithium salts, and the mixed precursor is sintered at uniform temperature to obtain the required lithium ion battery cathode material; and (3) the prepared lithium ion battery cathode material LiNixCoyM1-x-yO2 is basically prepared from micron-sized single crystal particles, and the average size of the single crystal particles is 2-20 micrometers. In addition, the product has excellent physical and electrochemical properties, such as ultra-low specific surface area, reasonable particle size distribution, good electrode processing properties, ultra-long cycle life, excellent rate capability, obvious high and low temperature cycling and storing properties and excellent safety; and the product can be widely used as a high-performance lithium ion battery cathode material. The invention provides the high-performance lithium ion battery cathode material and the preparation method thereof.

The invention discloses a preparation method of a high density nickel cobalt lithium manganate positive electrode material, LiNixCoyMnzO2. The preparation method comprises the following steps: firstly, mixing a nickel salt solution, a cobalt salt solution and a manganese salt solution according to a certain mol ratio, adding the mixed solution, a complexing agent solution and a precipitant solution together to a stirring reaction kettle with a base solution, fully reacting, carrying out solid-liquid separation, and washing and drying to obtain a globular nickel cobalt manganese oxyhydroxide precursor; calcining the precursor at the temperature of 350-900 DEG C for 2-20 hours to obtain a globular nickel cobalt manganese oxide precursor, and smashing the globular nickel cobalt manganese oxide precursor at high speed to obtain a mono-crystalline nickel cobalt manganese oxide precursor; mixing a lithium source and the mono-crystalline precursor according to a certain mol ratio, calcining at the temperature of 700-980 DEG C for 2-20 hours, and smashing and classing to obtain the mono-crystalline nickel cobalt lithium manganate positive electrode material. The preparation method provided by the invention has the advantages that the compacted density of the prepared nickel cobalt lithium manganate material is large, the specific capacity is high, the rate property and consistency are good, the preparation method is simple, and the preparation process is easy to control and operate.

The invention discloses a method for preparing an active electrode material of a lithium ion battery. The method comprises the following steps of: preparing a nano-crystal with electrochemical activity into an aqueous solution, and adding a carbon source and a surface active agent into the aqueous solution to form a uniform and stable mixture solution; and preparing the mixture solution into spherical particles under the condition that the temperature is between 200 and 900 DEG C through a spray granulation method, and performing heat treatment on the spherical particles in 400-900 DEG nitrogen gas so as to form the active electrode material of the lithium ion battery. Conductive networks are distributed in the active electrode material, and the active electrode material has a porous structure, so that the active electrode material has good lithium ion and electron transmission channels; and the lithium ion battery prepared from the active electrode material has high specific capacity, high-current charging and discharging and high cyclical stability. The method for preparing the electrode material of the lithium ion battery through a spraying method can be easily applied to mass production, and is generally used for preparing various high-performance electrode materials of the lithium ion battery.

The invention relates to a high-performance silicon-carbon cathode material and a preparation method thereof. The preparation method comprises the following steps: (1) dispersing silicon into a solvent, carrying out liquid-phase ball-milling, so as to obtain nano-silicon dispersion liquid, adding graphite, and carrying out liquid-phase ball milling so as to uniformly mix nano-silicon with graphite; (2) carrying out granulation on slurry obtained the step (1), so as to obtain graphite/nano-silicon composite particles; (3) carrying out granulation on the product of the step (2) and asphalt by virtue of a mixed kneading-pressing-crushing method, so as to obtain graphite/nano-silicon/asphalt composite particles, and carrying out mechanical fusion so as to realize spheroidization and uniform coating of the graphite/nano-silicon/asphalt composite particles in one step; and (4) carrying out carbonization, scattering and sieving, so as to obtain the high-performance silicon-carbon cathode material. The preparation method is simple and low in cost and can be used for easily producing the high-performance silicon-carbon cathode material in large scale.

The present disclosure relates to a cathode active material for a lithium secondary battery, and more particularly, to a cathode active material, which is used for a lithium secondary battery and is prepared to include a mixture of particles with different particle sizes and thereby to have an improved tap density. At least one particle of the mixture of the particles is provided to have a gradient in internal concentration.

The invention relates to a preparation method of a lithium ion battery cathode multicomponent composite material Lia(NixCoyMnz)NbO2 / M, and a preparation method of a precursor of the multicomponent material. The lithium ion battery cathode multicomponent composite material belongs to a nickel cobalt lithium manganate series cathode material, and can be expressed by a chemical formula Lia(NixCoyMnz)NbO2 / M. The preparation method comprises the following steps: measuring to prepare a standard mixed solution; under the protection of an inert atmosphere, adding a proper amount of a complexing agent and a precipitating agent into the mixed solution, adjusting the pH value to reach the end point of the reaction, filtering, washing and drying to obtain a spherical multicomponent precursor containing doped elements; grinding a lithium source and multicomponent precursor obtained in the step (2) in a ball mill; and placing the mixture obtained in the step (3) in a high temperature kiln to obtain a first sintering, so as to obtain the multicomponent material. The invention thorough mixing of precursor and lithium salt improves reaction activity, and strictly controls the temperature in the process of sintering, so as to obtain the multicomponent cathode material with regular morphology and uniform particle size.

Provided are a lithium iron phosphate composite material, the production method thereof and the use thereof The lithium iron phosphate composite material has a micro-size particle structure, which contains nano-size grains of lithium iron phosphate and graphene inside, and bears nano-carbon particulates outside. The lithium iron phosphate composite material has the properties of high conductivity, high-rate charge/discharge performance and high tap density. The production method comprises: preparing an iron salt mixed solution according to the mole ratio of P:Fe=1:1; adding the above solution into an organic carbon source aqueous solution, followed by mixing and reacting, so as to obtain nano-iron phosphate covered with organic carbon source; adding the above nano-iron phosphate covered with organic carbon source and a lithium source compound into an aqueous solution of graphene oxide, agitating, mixing, and then spray drying, so as to obtain a precursor of lithium iron phosphate composite material; calcinating said precursor in a reduction atmosphere and cooling naturally, so as to obtain said lithium iron phosphate composite material. The material is used for lithium ion battery or positive electrode material.

The invention discloses a multielement-doped lithium iron phosphate positive electrode material and a preparation method thereof. The general formula of the multielement-doped lithium iron phosphate positive electrode material is Li1-xAxFe1-y-zNbyMzPO4, wherein x, y and z are more than zero and not more than 0.1. The preparation method comprises the following steps: mixing lithium source, iron source, phosphorus source, compound of A and carbon source, roasting at 400-800 DEG C, then quickly reducing the temperature to room temperature, crushing, grinding to obtain an intermediate, then mixing the intermediate with niobium compound, compound of M and carbon source, roasting at 400-850 DEG C, then quickly reducing the temperature to room temperature, grinding, and grading to obtain the product. The preparation method of the invention can obviously increase the tap density of the material; and the material can have higher specific capacity and volume specific capacity and excellent cycle performance, meanwhile the material is applicable to industrialized stable production and has wide application prospect in the battery positive electrode material field for energy sources.

The invention relates to a method for preparing monodispersed silver powder with high tap density and low agglomeration, and the method is implemented through the following steps of uniformly mixing an acidic silver salt solution with a mixed reducing solution containing a L-ascorbic acid, a protective agent and a surfactant, and stirring the obtained mixture for reaction; and cleaning and then drying the obtained precipitate so as to obtain the monodispersed silver powder with high tap density and low agglomeration. Compared with the prior art, the silver powder prepared by using the method disclosed by the invention is high in tap density, small in particle diameter and dispersive range, high in degree of sphericity of particles, smooth in surface, small in specific surface area and easy for realization of mass production.

The invention provides a preparation method of lithium-nickel-cobalt-aluminum oxide for anode materials of lithium ion batteries. The method comprises: step 1, using a nickel-cobalt-aluminum precursor prepared through a coprecipitation method and doped with mixed ions as raw materials, putting the raw materials into a sealed hearth of a pressure furnace, continuously introducing oxygen until a fixed pressure value is formed, then heating to a pre-burning temperature and keeping warm for a period of time, and cooling to obtain an oxidized precursor; and step 2, adding measured lithium salt or lithium hydroxide into the oxidized precursor, ball milling and uniformly mixing; heating the uniformly mixed raw materials to a certain temperature and keeping warm for a period of time, and meanwhile continuously introducing oxygen to complete a sintering process, thereby obtaining the finish product. According to the invention, through a hyperbaric oxygen atmosphere, the oxygen are enabled to fully infiltrate into particles of the raw materials which has a certain accumulation thickness, thereby preventing situations that only surface materials are oxidized under a normal pressure, and ensuring a full conversion of Ni<2+> to Ni<3+> by a full pre-oxidation.

The invention discloses a high-density and small-particle size nickel-cobalt-manganese hydroxide and a preparation method thereof. For the high-density and small-particle size nickel-cobalt-manganesehydroxide provided by the invention, a general chemical formula is NixCoyMnz(OH)2, wherein x+y+z=1, x is larger than or equal to 0.3 and smaller than or equal to 0.8, y is larger than or equal to 0.1and smaller than or equal to 0.4, and z is larger than or equal to 0.1 and smaller than or equal to 0.4; the particle sizes are d10 larger than or equal to 2 microns, d50 equal to 2.5-4 microns and d90 smaller than or equal to 6 microns, the tap density is larger than or equal to 1.4g/cm<3>, the specific surface area is 5-20m<2>/g, and the shape is spherical or spheroidal. The invention also discloses the preparation method of the high-density and small-particle size nickel-cobalt-manganese hydroxide. The preparation method is strong in controllability, can stably control the particle sizes ineach production batch without using a surfactant and is low in production cost, high in efficiency and good in physicochemical index of a final product.

The invention discloses a method for preparing a lithium ferrous silicate or carbon ferrous silicate cathode material for a lithium ion battery, relates to a method for preparing a cathode material for a lithium ion battery and aims to solve the problems that the conventional prepared lithium ferrous silicate or carbon ferrous silicate composite is low in purity, inhomogeneous in granularity, and poor in electrochemical cycling stability. The method comprises the following steps of: 1, weighing a lithium salt compound, a ferric salt compound, a nano silica and a carbon source compound; 2, dispersing the weighed materials in the step 1 into a dispersing agent by a ball mill or ultrasonic dispersion method to obtain mixed liquor; 3, drying the mixed liquor by a spray drying method to obtain precursor powder; and 4, heating, namely heating the precursor powder obtained in the step 3 under the protection of inert gas in a certain flow rate, cooling naturally to room temperature, and thus obtaining the lithium ferrous silicate or carbon ferrous silicate cathode material for the lithium ion battery. The method is mainly applied to preparation of the lithium ferrous silicate or carbon ferrous silicate cathode material for the lithium ion battery.

The invention belongs to the technical field of a cathode material for a lithium primary battery, particularly relates to the field of preparation of the cathode material for a fluorocarbon battery, and in particular to a composite carbon fluoride cathode material for the lithium primary battery, a preparation method and an application thereof. The material is a composite material prepared by ballmilling and mixing a porous carbon fluoride material having a high tap density and a carbon fluoride material having a high graphitization degree and then fluorinating the mixture. The composite material has a carbon content of 38-60%, a fluorine content of 40-62% and a tap density of greater than 0.8g/ml; the mixing mass ratio is in the range of 1:0.1-1:10; and the composite material has high specific surface area, high tap density and high graphitization degree. Due to the high tap density of the material, the overall high volumetric specific energy of the material is guaranteed; through anion diffusion channel composed of porous carbon fluorides, the voltage hysteresis phenomenon at the initial stage of the battery discharge is effectively improved and the overall discharge performance of the material is improved.

The invention relates to a lithium nickel cobalt manganese oxide material precursor and a preparation method thereof and a lithium-ion battery prepared from the precursor. The lithium nickel cobalt manganese oxide material precursor is in a spherical form, primary particles are in the shape of emissive strips and the chemical formula is Ni(1-x-y)Co<x>Mn<y>(OH)<2>, wherein x is smaller than 0.2 and greater than 0 and y is smaller than 0.2 and greater than 0, the tap density is 1.6-1.9g/cm<3>, the median particle size D50 is 6-18 microns and the average pore size is 14-18nm. The preparation method of the lithium nickel cobalt manganese oxide material precursor is improved on the basis of a traditional one-step method, and the precursor prepared through the method has the characteristics of a precursor product under a single anti-oxidation condition and also has the characteristics of a precursor product under a single oxidation condition; and a ternary positive electrode material prepared from the precursor has the advantages of high capacity and high cycle performance, and also has the advantages of high compaction density, good heat stability and low self-discharge rate.

The present invention relates to ferric phosphate hydrate particles for use as a precursor of olivine type lithium iron phosphate particles, wherein the ferric phosphate hydrate particles exhibit at least one crystal structure selected from the group consisting of a strengite crystal structure and a meta-strengite (phosphosiderite) crystal structure, and have a sodium (Na) content of not more than 100 ppm and a molar ratio of phosphorus to iron (phosphorus/iron) of not less than 0.9 and not more than 1.1. The ferric phosphate hydrate particles according to the present invention are suitable as a precursor of olivine type lithium iron phosphate particles for a positive electrode substance of non-aqueous electrolyte secondary batteries, and are in the form of fine particles and have a very small content of impurities.

The invention discloses a ferrous lithium salt composite anode material and thepreparation method thereof. The technical problems which are needed to be solved are to enhance the high-rate electricity discharging of the anode material, and the manufacturing and the processing performances of battery electrodes are improved. The ferrous lithium salt composite anode material has lithium iron phosphate, and forms the composite material by adulterated with or covered by nickel-cobalt-manganese-lithium or nickel-cobalt-aluminum-lithium material. The weight ratio of the lithium iron phosphate and the nickel-cobalt-manganese-lithium or the nickel-cobalt-aluminum-lithium material is 9 to 7 : 1 to 3, and the micro-morphology is in a sphericity , or is like a sphericity, with a ration between a horizontal length and a vertical length of 1.2 to 2.5. The crystal is in the structure of an olivine type, a space group is Pbnm, and a particle diameter is 1 to 20microns. The preparation method comprises mixture, fusion processing and screen separation. Compared with the prior art, the ferrous lithium salt composite anode material has the advantages of capable of lowering specific surface area, capable of enhancing the voltage platform of the anode material, favorable processing performance, high tap density, favorable conductivity, favorable rate discharge performance and safe performance, capable of improving high and low temperature cycling performance, and favorable compatibility with various cathodes and electrolytes.

The invention provides a method for preparing a high-density special-shaped pure tungsten product through low-temperature sintering, and belongs to the technical field of powder injection molding. The method comprises the technological processes that an air flow mill is adopted for carrying out dispersing and staging treatment on commercially available high-purity tungsten powder, the treated powder and a bonding agent are evenly mixed for mixing, and even feed is obtained; the feed is subjected to injection molding to form a blank in a certain shape; and the formed blank is subjected to solvent degreasing and hot degreasing and then is sintered, and the tungsten product is obtained. Powder is subjected to dispersing and staging treatment through the air flow mill under the protective atmosphere, the powder is driven by gas to collide with each other and can be treated on a large scale, and no impurity is introduced; the particle size distribution of the treated powder becomes narrow, and the shape of particles becomes regular and is similar to a spherical shape; and loose-fitting tap density is increased, the loading amount of the injection-molded powder is correspondingly improved to 55%-70%, and the density of the pure tungsten product manufactured after sintering of the hydrogen atmosphere of 1,900 DEG C is higher than 96%.

The invention discloses a preparing method for a silicon-carbon composite negative electrode material for a lithium ion battery. The preparing method includes the following steps that 1, flake graphite, a polymer solution and nanometer silicon dispersion liquid are evenly mixed, dried and carbonized in a protective atmosphere; 2, pitch and spherical graphite are mixed, ground, placed in an inert protective atmosphere, and subjected to heat treatment to obtain modified spherical graphite; 3, a binder, the modified spherical graphite and the mixed material obtained after carbonization in the step 1 are added into solvent, dispersed evenly and dried to obtain a precursor material; 4, the precursor material is carbonized to obtain the silicon-carbon composite negative electrode material. In the process of the preparing method, it is unnecessary to add special dispersant, nanometer silicon is evenly dispersed in the graphite by means of some ionic groups existing in the polymer solution and high viscosity, the polymer solution has certain stability, and the possibility of nanometer silicon aggregation in the drying process is reduced.

The invention discloses solar energy battery electrode-conducting silver slurry containing micron-size mixed silver powders. The silver slurry comprises mixed silver powders, glass powders, organic carriers and mixed silver powders, wherein the mixed silver powders are composed of, by weight, 5% to 15% of silver powders with grain size from 0.1 micrometers to 1 micrometer, 30% to 50% of silver powders with grain size from 1 micrometer to 3 micrometers, and the balance silver powders with grain size from 3 micrometer to 6 micrometers. According to the solar energy battery electrode-conducting silver slurry containing micron-size mixed silver powders, the silver powders are high in tap density and can form dense net with excellent conducting performance after sintering so that the contact area of the silver silicon interface can be increased and the conversion efficiency of battery electrodes is high; the surface of the electrodes is smooth, and the electrodes have good in solderability and strong adhesive force.

A preparation method of lithium iron phosphate with high tap density relates to the technical field of positive electrode active substance preparation of Li-ion battery. The method comprises the following two steps: firstly, synthesizing submicron-scale lithium iron phosphate powder by soft chemical method; and secondly, spraying a polymer solution into the lithium iron phosphate powder while stirring at high speed to granulate, and sintering. The positive electrode active substance lithium iron phosphate of the Li-ion battery prepared by the two-step method has high tap density of 1.5 g/cm, low specific surface area smaller than 10 m/g, and average particle size of 5 to 15 mum. The method has the advantages of simple implementation, low cost and excellent material processability, and suits industrial production.

The invention relates to a preparation method of mono-dispersed highly crystalline silver powder with adjustable particle size. The preparation method comprises uniformly mixing an acidic silver salt solution and a mixed reducing solution containing a reducing agent, a dispersing agent and a stabilizing agent, precipitating, washing and drying to obtain the mono-dispersed highly crystalline silver powder with adjustable particle size, wherein the particle size of the silver powder can be adjusted by adjusting the amount of the dispersing agent and the stabilizing agent. In comparison with the prior art, the silver powder has an adjustable particle size, and D50 of the silver powder can be controlled to a range close to 0.5 mum, 1.0 mum, and 2.5 mum. Meanwhile, the silver powder has the advantages of narrow particle size distribution range, high tap density, high particle sphericity, smooth surface, and small specific surface area, and is easy for large-scale production.

A method of producing carbon nanofibers includes grinding untreated carbon nanofibers produced by a vapor growth method. The untreated carbon nanofibers are ground so that the ground carbon nanofibers have a tap density 1.5 to 10 times higher than that of the untreated carbon nanofibers. A method of producing a carbon fiber composite material includes mixing carbon nanofibers into an elastomer, and uniformly dispersing the carbon nanofibers in the elastomer by applying a shear force to obtain a carbon fiber composite material.

Disclosed is a preparation method for multiple precursors with concentrated particle size distribution by multistage continuous synthesis. The preparation method comprises the following steps of: 1) preparing a metal salt solution, an alkali solution and an ammonium hydroxide solution; 2) enabling a reaction kettle and a solid concentration thickener to be connected in series; 3) injecting the metal salt solution, the alkali solution and the ammonium hydroxide solution into the reaction kettle 1, wherein the slurry in the reaction kettle 1 is pumped into the thickener 1 for solid-liquid separation to increase solid content when the liquid level in the reaction kettle 1 reaches the full kettle state, and the thick slurry in the thickener 1 is pumped into a reaction kettle 2; 4) performing stirring when the reaction kettle 2 is full of the slurry, and adding the metal salt solution, the alkali solution and the ammonium hydroxide solution to continue a continuous precipitation reaction, and then overflowing the product in the reaction kettle 2 into an aging tank 1; and 5) enabling the product in the aging tank 1 to be centrifuged, washed and dried. The preparation method has the advantages that the technology is simple, easily operated, energy-saving and environment-friendly. The product features good appearance, concentrated particle size distribution, high vibration density andhigh efficiency.

The invention discloses a preparation method of vanadium oxide and lithium iron phosphate composite materials with a high tap density. The method comprises the following steps: (1) preparing a lithium iron phosphate precursor; (2) preparing the vanadium oxide and lithium iron phosphate composite materials; and (3) molding processing, sintering under a temperature of 500-800 DEG C in an atmosphere of nitrogen, crushing the sintered materials, and sieving by a sieve of 100-400 meshes to obtain the vanadium oxide and lithium iron phosphate composite materials with the high tap density. The method can greatly improve diffusion capacity of lithium ion among particles, and thus improve power performance of the lithium iron phosphate. Spherical-like precursors are compacted and sintered after a drying processing of a secondary mixing, and thus pores among particle are reduced, components of the precursors are combined tightly, and the reaction is carried out adequately. The sintered lithium iron phosphate particles are round in surface morphology, and can effectively improve tap density of the materials.

The invention discloses a silicon-carbon composite electrode and a preparation method thereof. The silicon-carbon composite electrode is of a shell-core structure, wherein a core contains silicon powder, a hollow carbon sphere and an inorganic lithium salt compound, the hollow carbon sphere is doped into the silicon powder, and the inorganic lithium salt compound is electrically deposited between the silicon powder and the hollow carbon sphere; and a shell is a high-molecular polymer. According to the silicon-carbon composite electrode prepared by virtue of the preparation method, by utilizing lithium salt deposited on the surface of silicon, the lithium ion transmission rate during charging and discharging is increased, sufficient lithium ions are provided for the formation of an SEI membrane, the initial efficiency can be obviously improved, the expansion rate of a silicon material can be decreased, and the cycle performance of the silicon material can be improved; and meanwhile, the silicon-carbon composite electrode has the characteristics of high stability and strong stability at 100-150 DEG C, the contact between the lithium salt material and air can be avoided, and the processability and the safety performance of the lithium salt material can be improved; and furthermore, the polymer has relatively good dissolving property with an electrolyte solvent, so that the polymer can serve as lithium salt, and the initial efficiency, safety performance and energy density of a cathode material are improved.

The invention discloses a method for preparing lithium cobaltate positive pole material for a lithium ion cell and the obtained lithium cobaltate positive pole material. The method comprises the following steps: adopting a multiple-step synthesizing process; in a first synthesis, adopting excessive lithium so as to obtain larger lithium cobaltate particles at lower temperature; and before a second synthesis, adhering mixed powder of cobalt carbonate and lithium carbonate with small particle size and larger specific surface area to the one-step synthesized lithium cobaltate large particles through a mechanical granulation mode. The method can effectively improve the particle size and the tap density of the lithium cobaltate positive pole material so as to improve the compacted density and the volume specific capacity of the positive pole material.

The invention relates to a one-step preparation method of LiFePO4 powder coated with carbon. Lithium compounds, ferrite and phosphorous compounds are taken as raw materials, additive is antioxidant and glutin that accounts for 1-6% of the mass of theoretically generated lithium ferrous phosphate; the glutin is dissolved in de-ionized water which is then heated and stirred at the temperature of more than 40 DEG C to obtain the aqueous solution of the glutin. The prepared ferrite solution and the glutin solution are added to a Li3PO4 system to be mixed uniformly; the mixed solution reacts at the temperature of 120-170 DEG C for 2-5h; the obtained product is dry lithium ferrous phosphate powder coated with the glutin; the prepared powder is filled in a quartz crucible and calcined at the temperature of 550-750 DEG C under the protection of N2 atmosphere, and finally the lithium ferrous phosphate powder coated with carbon is obtained. The shape of the prepared lithium ferrous phosphate particles is uniform and columnar with the grain diameter being 400nm, the surface coating is thin and uniform amorphous carbon, has high tap density, is beneficial to improving the electrochemical performance of materials and is suitable for being used as anode material. The method has simple process route and no pollution and is suitable for scale production.

The invention discloses a method for reducing the sulphur content of a ternary precursor. Sulfate is used as a ternary salt raw material, and the ternary salt raw material, an alkaline solution and acomplexing agent are added to a reaction kettle for co-precipitation to prepare the ternary precursor, after co- precipitation reaction is carried out for 5-15 hours, pure water is added continuouslyor intermittently to the reaction kettle to replace clear liquid in the reaction kettle, and meanwhile, the alkaline solution and the complexing agent are added to keep a reaction system stable. The problem that the sulphur content in the ternary precursor exceeds the standard due to the fact that the sulfate is adsorbed on the surface of a crystal during the growth of the crystal and then wrappedinside the crystal is solved, the sulphur content of the prepared ternary precursor after one-time washing is less than 530 ppm, and during the subsequent water washing process, water resources are effectively saved; and the impurity content is reduced, the jolt ramming density of the ternary precursor is increased, and the morphology of the ternary precursor is not affected.

The invention discloses a lithium ion battery graphite anode material and a preparation method thereof. The preparation method includes the steps of: 1) heating and kneading a mixture of natural graphite and an adhesive; 2) performing hot isostatic pressing moulding at 500-1000 DEG C under 50-100 MPa; 3) performing carbonization; 4) performing graphitization; and 5) crushing and classifying a product. The lithium ion battery graphite anode material has high tap density, large discharge capacity and good cycle performance, is reduced in internal pores of graphite particles, reduces expansion and is improved in cycle performance.