4928results about "Silicon compounds" patented technology

The invention relates to the technical field of lithium ion battery materials, in particular to a chemical liquid phase deposition silicon-carbon negative electrode material and a preparation method and application thereof.The silicon-carbon negative electrode material comprises a porous carbon skeleton and nanometer silicon particles deposited on the surface and in pore channels of the porous carbon skeleton; the carbon source coating layer is used for coating the porous carbon skeleton and the nano silicon particles. The interior of the composite structure of the silicon-carbon negative electrode material is nanometer silicon particles deposited on the surface and in pore channels of a porous carbon skeleton, and the outer layer is a coating layer; porous carbon is used as a continuous and stable carbon skeleton to effectively relieve volume expansion and particle fragmentation of the silicon-based material, and the outermost coating layer improves the structural stability and conductivity of the composite material, so that the electrochemical cycle stability is improved; according to the structure of the silicon-carbon negative electrode material, the advantages of an embedded structure and a shell-core structure are combined, a stable carbon skeleton is provided for the silicon-carbon negative electrode material, a limited expansion space is provided for silicon particles, crushing is prevented, and the cycling stability of the negative electrode material is greatly improved.

The invention provides a silicon-carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: a) mixing a phenol monomer, an aldehyde solution, ammonia water and water, dropwise adding a boric acid solution for reaction, and curing to obtain boron-containing phenolic resin; b) carbonizing the boron-containing phenolic resin obtained in the step a), mixing with alkali, and activating to obtain boron-doped porous carbon; and c) carrying out silicon deposition on the boron-doped porous carbon obtained in the step b) by adopting a gaseous silicon source, carrying out carbon coating by adopting a gaseous carbon source, and cooling to obtain the silicon-carbon negative electrode material. Compared with the prior art, the preparation method provided by the invention has the advantages that a conductive network can be formed by doping the boron element, the electron concentration can be improved, the electron transfer rate is favorably improved, the conductivity of the material is effectively enhanced, and the rate capability of the negative electrode material is effectively improved; meanwhile, the residual carbon rate in the porous carbon preparation process can be greatly increased, and the cost of the whole silicon-carbon negative electrode material is effectively reduced.

The invention discloses a silicon-carbon negative electrode material, porous carbon and a preparation method, the porous carbon is prepared by mixing ammonium fluoride and a pre-carbonized material to prepare a premix; and putting the premix in an inert atmosphere, and carrying out pre-activation, drying, carbonization, activation and crushing treatment to obtain the composite material. And uniformly depositing the nano silicon particles into the porous carbon skeleton through a mature CVD (Chemical Vapor Deposition) process to obtain the silicon-carbon composite material. Fluorine and nitrogen co-doping modification can increase the defect degree of a carbon skeleton, efficiently relieve mechanical stress accompanied by lithium storage volume expansion of the silicon negative electrode in a micro scale, provide abundant lithium ion transport and mass transfer channels and enhance the conductivity of porous carbon, and ammonium fluoride is used as a supplementary activator besides water vapor, so that the porosity of the porous carbon is further improved, and the conductivity of the porous carbon is improved. An effective space is provided for uniform deposition of silicon, the fluorine-containing carbon layer can induce formation of a high-stability SEI film rich in LiF on the surface of the nano silicon material, and the interface stability and coulombic efficiency of the silicon negative electrode are further improved.

The invention provides hydrophobic silica wet gel, hydrophobic silica aerogel, and methods that can be used to form an enhanced hydrophobic silica aerogel sheet having an advantageous combination of properties. Some embodiments of the invention provide a hydrophobic silica aerogel having advantageous properties, such as desirable performance on visible transmission, haze, or both.

The invention belongs to the technical field of battery materials, and particularly relates to a method for preparing a porous carbon structure containing a sub-nanoscale ionic conduction improvement layer by utilizing atomic layer deposition and application. The invention discloses a porous carbon-silicon negative electrode structure, which is characterized in that a sub-nano-scale ion conduction improvement layer is added between a porous carbon substrate and silicon particles, and the sub-nano-scale ion conduction improvement layer comprises silicon carbide, aluminum phosphide, aluminum nitride, aluminum oxide, lithium phosphate, aluminum phosphate and lithium aluminum phosphate. Meanwhile, the invention also discloses a preparation method of the porous carbon-silicon negative electrode structure, namely, a sub-nano-scale ion conduction improvement layer is deposited on the porous carbon substrate through an atomic layer deposition method, so that the binding force between the sub-nano-scale ion conduction improvement layer and silicon particles and an ion transport channel are increased, and the ion conduction of a vapor deposition silicon-carbon negative electrode material is improved; the polarization of the material is effectively reduced, so that the rate capability of the battery is improved, and the cycling stability of the porous carbon structure battery is improved.

The invention discloses metal element-doped nano silicon carbon as well as a preparation method and application thereof, and relates to the field of negative electrode materials. The nano silicon carbon takes porous carbon as a carbon skeleton, and the porous carbon is sequentially attached with nano silicon and coated with a carbon material layer through a chemical vapor deposition method; the porous carbon is prepared by carbonizing resin containing metal nitride after alkali activation and pore forming, and the resin containing the metal nitride is prepared by condensation polymerization of a phenolic compound, an aldehyde compound and the metal nitride in the presence of a catalyst. The porous carbon is doped with the metal nitride in the resin polycondensation process, the conductivity of the nano silicon carbon is effectively improved, the powder resistance is reduced, holes in the surface of the porous carbon provide more expansion space for deposited nano silicon, a carbon material layer formed by subsequent deposition and coating provides a protection effect, the reaction between silicon and an electrolyte can be inhibited, and the service life of the nano silicon carbon is prolonged. A stable SEI film is formed, the cycling stability of the material is improved, the volume expansion rate of a pole piece is inhibited, and the cycling life and the stability of the battery are improved.

The invention relates to the technical field of lithium ion battery silicon-carbon coating, in particular to a silicon-carbon composite material, a silicon-carbon negative electrode material, a preparation method of the silicon-carbon negative electrode material and a battery. The preparation method of the silicon-carbon composite material comprises the following steps: S1, mixing porous carbon and a gaseous organic silicon source for reaction under the conditions of 450-550 DEG C and 100-200 kPa; s2, under the condition of 500-800 DEG C, carrying out carbon coating on the product obtained in the step S1 by using a carbon source to obtain a silicon-carbon composite material; the flow velocity of the gaseous organic silicon source is 12-30L / min. The silicon-carbon composite material provided by the invention has good conductivity, and the subsequently prepared silicon-carbon negative electrode material and battery material have good electrochemical performance.

The invention provides hydrophobic silica wet gel, hydrophobic silica aerogel, and methods that can be used to form an enhanced hydrophobic silica aerogel sheet having an advantageous combination of properties. Some embodiments of the invention provide a hydrophobic silica aerogel having advantageous properties, such as desirable performance on visible transmission, haze, or both.

The invention provides a doped electrode material based on porous silicon carbon and a preparation method thereof.The preparation method comprises the steps that a resin base material is smashed and then put into a high-temperature furnace to be subjected to a carbonization process, the carbonization temperature ranges from 300 DEG C to 1500 DEG C, an alkaline additive, a phosphorus source material and a nitrogen source material are sequentially added in the temperature interval, and phosphorus-nitrogen co-doped porous carbon is obtained; the preparation method comprises the following steps: mixing a silicon dioxide microsphere template into phosphorus-nitrogen co-doped porous carbon, adding a first coating carbon source to carry out first coating treatment, and etching the silicon dioxide microsphere template by using an etching solution to obtain a prefabricated object with a cavity structure; and putting the prefabricated object with the cavity structure into a fluidized bed reactor, introducing silicon source gas and a surface activation auxiliary agent, carrying out deposition at 400-550 DEG C, and then adding a second coating carbon source to carry out secondary coating treatment, thereby obtaining the doped electrode material based on porous silicon carbon. Therefore, the expansion coefficient of the electrode material is effectively reduced, and the rate capability is improved.

The preparation method of the silicon-carbon composite material comprises the following steps: uniformly mixing a carbon source, a pore forming agent and a cross-linking agent, and introducing peroxide gas into a tubular furnace for sintering to obtain porous carbon; uniformly mixing the porous carbon with liquid silane and a surfactant, and transferring the mixture into a high-pressure reaction kettle for reaction to obtain a silicon-carbon precursor; and introducing the obtained material into a carbon source gas containing a heteroatom gas for deposition to obtain the silicon-carbon composite material. The obtained material generates porous carbon with high strength and high pore volume by utilizing the cross-linking agent and the pore-forming agent thereof, so that the expansion is reduced; and the liquid silane has the characteristics of low decomposition temperature, low cost and high safety performance, so that the specific capacity is improved, and the cost is reduced.

The invention discloses a porous carbon and silicon carbon material as well as a preparation method and application thereof. The pore structure of the porous carbon comprises mesopores and micropores; in the pore structure, the pore volume ratio of mesopores is 3-20%, and the pore volume ratio of micropores is 80-97%; the adsorption and desorption isotherm of the mesopores is one or more of an H1 type hysteresis loop, an H2 type hysteresis loop and an H3 type hysteresis loop; the pore structure is filled with carbon particles, and the carbon particles are spherical carbon particles or fusiform carbon particles. By regulating and controlling the pore structure of the porous carbon, the performance of the silicon-carbon negative electrode is remarkably improved, and the double advantages of high strength and low expansion are achieved. The preparation method disclosed by the invention has obvious advantages in the aspects of cost, time and safety.

The invention discloses porous carbon, a silicon-carbon negative electrode material, a preparation method, a pole piece and a battery. The porous carbon comprises a carbon skeleton and calabash-shaped pores distributed in the carbon skeleton, the average pore size of the porous carbon is 0.05-15 nm, and the pore volume is 0.05-2 cm < 3 > / g. The preparation method of the porous carbon comprises the following steps: S1, carrying out melting treatment on a mixture, and filtering; the mixture comprises asphalt-based porous carbon and asphalt, the average pore size of the asphalt-based porous carbon is 0.1-20 nm, the pore volume of the asphalt-based porous carbon is 0.1-2 cm < 3 > / g, and the mass content of quinoline insoluble in the asphalt is 0.003%-3%; and S2, carrying out carbonization treatment on the solid obtained by filtering in the step S1. The porous carbon with most closed pores, small aperture and calabash-shaped pore body structure is beneficial to subsequent silane gas deposition, electrolyte isolation and silicon elementary substance expansion inhibition, and can well cooperate with high first effect and high capacity of a silicon-carbon negative electrode material.

The invention discloses a silicon-carbon material, a preparation method and application thereof and a lithium ion battery. The preparation method of the silicon carbon material comprises the following steps: S1, performing carbonization treatment and activation treatment on a mixture of a carbon source and transition metal salt to obtain porous carbon; s2, performing carbon deposition on the porous carbon by adopting a chemical vapor deposition method, and growing a carbon nanotube in situ to obtain a first precursor; s3, performing silicon deposition on the first precursor by adopting a chemical vapor deposition method to obtain a second precursor; s4, carrying out carbon coating on the second precursor; and carrying out acid pickling and drying to obtain the silicon-carbon material. The silicon-carbon material is relatively good in conductivity and pressure resistance and excellent in expansion inhibition performance, and the prepared lithium ion battery can give consideration to excellent first effect, gram volume, rate capability and cycle performance.

A silicon-carbon material, a preparation method therefor, a secondary battery, and an electric device. The silicon-carbon material comprises silicon-carbon composite particles; the silicon-carbon composite particles comprise a porous carbon material, nano-silicon grains and a silicon carbide material layer; the porous carbon material is provided with through pores, the nano-silicon grains are located in the through pores, and the silicon carbide material layer is partially located on through pore walls; the grain size of the nano-silicon grains is not smaller than the average pore diameter of the porous carbon material. The silicon-carbon material is used as an active material of a negative electrode sheet, thereby improving the cycle performance of batteries.

The invention relates to the technical field of lithium battery negative electrode materials, in particular to a conductive polymer coated silicon-carbon composite material and a preparation method and application thereof.The conductive polymer coated silicon-carbon composite material comprises a porous silicon-carbon material and a conductive polymer, and the pore width of a porous structure in the conductive polymer coated silicon-carbon composite material is smaller than the in-pore width; the porous silicon carbon material comprises porous carbon and silicon particles, the conductive polymer comprises a polymer frame and a conductive material, the conductive material comprises at least one zero-dimensional conductive substance, at least one one-dimensional conductive substance and at least one two-dimensional conductive substance, and the component content of each conductive substance meets the formula: # imgabs0 # mA is the mass percentage of the component A in the whole system, Pc is the mass percentage of the component B in the whole system, and the component B is the mass percentage of the component B in the whole system. A is the mass fraction percolation threshold of the component A in the polymer framework. According to the invention, not only can a screening type structure be effectively constructed, but also the rate capability can be greatly improved, and finally the silicon-carbon composite material with high initial efficiency, low expansion, high cycle stability and excellent fast charging performance is obtained.

The invention discloses a silicon-carbon composite material which comprises porous carbon, silicon-containing particles are distributed on the surface of the porous carbon and in pore channels, the surfaces of the silicon-containing particles are coated with aluminum silicate layers, and the surface of the porous carbon is coated with a carbon layer. The invention also discloses a preparation method of the silicon-carbon composite material, which comprises the following steps: sequentially carrying out vapor deposition on the porous carbon by using silane, aluminum steam and vapor carbon to obtain the silicon-carbon composite material. The invention also discloses an application of the silicon-carbon composite material in a negative electrode material. When the silicon-carbon composite material is used in the lithium ion battery, the initial coulombic efficiency and the capacity retention rate of the lithium ion battery can be improved, and the expansion rate of a pole piece is reduced.

The invention discloses a preparation method and application of interpenetrating network gel based on bentonite minerals, and belongs to the technical field of collapsible loess improvement. According to the prepared bentonite mineral interpenetrating network gel (BT-PAA / PEG / PVA), bentonite serves as a crosslinking node and cooperates with a PAA ion network, a PEG flexible chain segment and a PVA rigid hydroxyl network to construct a triple interpenetrating structure, high water absorption, compression resistance, salt resistance and long-term stability are achieved, the gel is applied to collapsible loess improvement, and the collapsible loess improvement effect is good. And gel particles and soil particles are combined to form an anchoring effect, so that the permeability of a soil body is reduced and the soil body is prevented from collapsing.

The invention provides a biomass-derived spherical porous carbon material and a preparation method thereof, and a silicon-carbon negative electrode material and a preparation method thereof, and relates to the field of lithium ion batteries. The preparation method of the biomass-derived spherical porous carbon material comprises the following steps: carrying out pre-carbonization treatment on vinasse to obtain pre-carbonized vinasse, mixing the pre-carbonized vinasse with an acidic solution, and washing with water until the mixture is neutral to obtain pre-treated vinasse; mixing the pretreated vinasse with a pore-forming agent, a binder and water to prepare slurry, and performing spray drying on the slurry to obtain a spheroidized precursor; carrying out carbonization treatment on the spheroidized precursor; washing the carbonized spheroidized precursor with water until the spheroidized precursor is neutral, and drying the spheroidized precursor to obtain an intermediate; and activating the intermediate with water vapor to obtain the biomass-derived spherical porous carbon material. The material with a regular spherical and porous structure can be prepared, the material can be used for preparing a silicon-carbon negative electrode material with a stable structure, and the electrochemical performance of the silicon-carbon negative electrode material is improved.

The invention provides hydrophobic silica wet gel, hydrophobic silica aerogel, and methods that can be used to form an enhanced hydrophobic silica aerogel sheet having an advantageous combination of properties. Some embodiments of the invention provide a hydrophobic silica aerogel having advantageous properties, such as desirable performance on visible transmission, haze, or both.

The invention relates to methods for synthesizing an engineered adsorbent suitable for the selective extraction of lithium from brine solutions. The invention describes the advantages of introducing mixed metal oxides into the crystal lattice of anatase titania precursor. The invention offers significant advantages, including high adsorption capacity of the ion sieve, enhanced chemical stability of the sorbent, and higher lithium selectivity.

The invention relates to the technical field of batteries, in particular to silicon carbon particles, a negative plate and a battery. The invention provides a silicon-carbon particle. The surface of the silicon-carbon particle is provided with a concave part; the number N of the concave parts on the surfaces of the silicon carbon particles is greater than or equal to 1; the diameter of the concave part is 0.05 [mu] m-5 [mu] m; the depth of the recessed part is 10 nm to 5 [mu] m. The sunken parts are arranged on the surfaces of the silicon-carbon particles, so that the cycle stability and the expansion performance of the silicon-based negative electrode material are improved.

The invention provides a silicon-carbon negative electrode material, a preparation method thereof and a lithium ion battery. The silicon-carbon negative electrode material comprises a porous carbon substrate, nano silicon deposited on the surface and in pores of the porous carbon substrate, and a conductive polymer layer coated on the surface of the nano silicon, the porous carbon matrix is formed by taking zinc gluconate as a carbon source through high-temperature pyrolysis and carbonization. According to the silicon-carbon negative electrode material, the preparation method thereof and the lithium ion battery provided by the invention, the silicon-carbon negative electrode material has high specific surface area, excellent conductivity and stable cycle performance, and shows excellent cycle stability and relatively high reversible capacity in the charge-discharge process when being used for the lithium ion battery; the energy density and the cycle life of the lithium ion battery are effectively improved, a new technical approach is provided for preparation of the silicon negative electrode material of the lithium ion battery, and the preparation method has a wide application prospect.

The invention relates to the field of batteries, in particular to a preparation method and system of a silicon-carbon material, and the preparation method comprises the following steps: pretreating porous carbon, conveying the pretreated porous carbon to a fluidized bed reactor, sequentially introducing a silicon source gas and a carrier gas for silicon deposition treatment, heating, introducing a carbon source gas, adjusting the flow of the carrier gas for carbon coating treatment, and discharging and cooling to obtain a finished product, meanwhile, reaction tail gas is recycled. The preparation system comprises a gas inlet unit, a fluidized bed reactor unit, a tail gas circulation unit, a feeding preheating unit and a discharging unit. The fluidized bed reactor comprises an outer shell, an up-down stirring device, a heat exchange assembly and an air distribution assembly, and efficient reaction and temperature control can be achieved. The silicon-carbon material prepared by the method has excellent electrochemical performance and is suitable for a lithium ion battery negative electrode material. The unique porous structure and the uniform carbon coating layer effectively improve the conductivity and the structural stability of the material, and meanwhile, the volume expansion effect of silicon in the charging and discharging process is reduced.

To provide a composition for chemical mechanical polishing and a polishing method that can effectively suppress contamination of foreign matters during manufacturing and can polish the surface of a semiconductor substrate to a flat surface.SOLUTION: The composition for chemical mechanical polishing according to the present invention contains (A) abrasive grains including silica and (B) a liquid medium, in the (A) component, when the peak intensity of 490 cm-1 derived from a 4-membered ring measured by Raman spectroscopy is x and the peak intensity of 800 cm-1 derived from a multi-membered ring measured by Raman spectroscopy is y, x / y is 4.5 to 6.0, and the (A) component has at least one functional group selected from those represented by the following general formulae (1) to (4), -SO3-M+ (1), -COO-M+ (2), -NR1R2 (3), -N+R1R2R3M- (4).SELECTED DRAWING: None

The invention relates to a silicon-carbon composite material, a preparation method thereof and a lithium ion battery. The preparation method comprises the following steps: adding porous carbon into a fluidized bed, heating and introducing alkaline mixed gas to obtain amino porous carbon; transferring the amino porous carbon into fluidized bed equipment, vacuumizing, heating, and introducing hydroxyl silane gas for nano silicon deposition; after deposition, introducing ultraviolet light for polymerization and oxidation to obtain a modified silicon-carbon precursor material; transferring the modified silicon-carbon precursor material into a tubular furnace, introducing inert gas to discharge air in the tube, and performing first carbonization to obtain a silicon-carbon material; and adding the resin into an organic solvent, adding the fast ion conductor and the silicon carbon material to be uniformly dispersed, performing spray drying, and performing secondary carbonization to obtain the fast ion conductor coated silicon carbon composite material. The preparation method provided by the invention is simple and efficient, and the prepared silicon-carbon composite material can improve the fast charging performance and is suitable for a negative electrode material of a high-energy-density lithium ion battery.

The invention relates to a silicon-carbon composite material and a preparation method thereof, a negative pole piece, a secondary battery and a device, the silicon-carbon composite material comprises a carbon matrix with a pore structure and a silicon-based material distributed in the pore structure of the carbon matrix, and the silicon-carbon composite material contains phosphorus element. The silicon-based material in the silicon-carbon composite material improves the capacity of the carbon matrix, and the carbon matrix with the pore structure can be used as a buffer medium for volume expansion of the silicon-based material in the charging and discharging process while improving the conductivity of the silicon-based material, so that the problem that the volume of the secondary battery is increased due to silicon expansion is effectively relieved; and the phosphorus element doped in the skeleton of the carbon matrix is beneficial to improving the electronic conductivity of the material, so that the cycle performance of the battery is improved.

The invention discloses a lithium-rich manganese-based positive electrode material with a core-shell structure, the general formula of the lithium-rich manganese-based positive electrode material is Li < 1 + a > Mn < x > Co < y > Ni < z > O < 2-b-d > (XOc) X < d >, the lithium-rich manganese-based positive electrode material has the core-shell structure, the core is a lithium-rich manganese-based material Li < 1 + a > Mn < x > Co < y > Ni < z > O < 2-b > (XOc) doped with disordered polyanions, and the shell is a lithium-rich manganese-based material Li < 1 + a > Mn < x > Co < y > Ni < z > O < 2-d > X < d > doped with gradient non-metal ions. The invention also provides a preparation method of the lithium-rich manganese-based positive electrode material with the core-shell structure, and the lithium-rich manganese-based positive electrode material with the core-shell structure is prepared by adopting a combined means of rapid Joule heat treatment and surface plasma cleaning treatment. The polyanion-doped bulk phase disordered structure design and the surface gradient non-metal ion-doped core-shell structure are realized. Wherein the bulk phase polyanions can fix transition metal elements to inhibit migration of the transition metal elements to a lithium layer, harmful consumption of active sites is reduced, and a lattice structure is stabilized. In addition, strong bond energy between surface nonmetal and transition metal elements can inhibit dissolution of transition metal in the circulation process, irreversible oxidation of oxygen is reduced, and generation of harmful phase change is inhibited.

The invention discloses a system and a process method capable of continuously preparing a high-gram-volume and low-expansion silicon-carbon material, and belongs to the technical field of lithium ion battery negative electrode material preparation, the system comprises a raw material bin, a preheating zone A, a multi-stage silicon deposition reactor, a preheating zone B, a multi-stage carbon coating reactor and a gas-solid separation device which are communicated in sequence; the preheating zone A, the multi-stage silicon deposition reactor, the preheating zone B and the multi-stage carbon coating reactor are all communicated with a nitrogen main air duct through nitrogen branch air ducts; the multi-stage silicon deposition reactor is communicated with the silane gas main air duct through a plurality of silane gas branch air ducts, and the multi-stage carbon coating reactor is communicated with the acetylene gas main air duct through a plurality of acetylene gas branch air ducts. The large-scale continuous production of the silicon-carbon material with high gram volume and low expansion rate can be realized, the uniformity of silicon deposition and carbon coating is good, the production efficiency can be improved, the energy consumption can be reduced, the manufacturing cost of the silicon-carbon material can be reduced, and the product yield can also be improved.

The invention relates to a preparation method of composite porous carbon beneficial to silicon deposition and a silicon-carbon composite negative electrode. The method comprises the following steps: (P1) carrying out surface oxidation treatment on porous carbon fine powder to obtain oxidized porous carbon fine powder; (P2) adding the oxidized porous carbon fine powder and ether polycarboxylic acid silanol into a solvent to obtain ether polycarboxylic acid silanol modified porous carbon fine powder; the ether polycarboxylic acid silanol is prepared by copolymerizing a polyether macromonomer, an acrylic monomer and an alkenyl silane coupling agent in water; (P3) soaking the ether polycarboxylic acid silanol modified porous carbon fine powder in a salt aqueous solution to obtain catalyst-loaded porous carbon; (P4) mixing the porous carbon loaded with the catalyst with a carbon source precursor solution, and performing spray drying to obtain a composite carbon precursor; and (P5) carbonizing and activating the composite carbon precursor to obtain the composite porous carbon beneficial to silicon deposition. The composite porous carbon prepared by the invention is beneficial to more uniform deposition of silicon in pores of the core porous carbon fine powder.

The invention belongs to the technical field of lithium ion battery materials, and discloses a bismuth silicate coated lithium ferric manganese phosphate material, a preparation method thereof and a lithium ion battery. The bismuth silicate coated lithium ferric manganese phosphate material comprises lithium ferric manganese phosphate and a coating layer coating at least part of the surface of the lithium ferric manganese phosphate, and the coating layer is made of bismuth silicate. Carrying out ball-milling mixing on the ferric manganese phosphate material, a lithium source, a carbon source and water to obtain mixed slurry; performing low-temperature spray drying on the mixed slurry to obtain a spray material; and carrying out wet mixing on a silicon source, a bismuth source and the spray material, carrying out high-temperature pyrolysis on the wet-mixed material in a spray pyrolysis furnace, and sintering to obtain the bismuth silicate coated lithium ferric manganese phosphate material. When the bismuth silicate coated lithium ferric manganese phosphate material is used as a positive electrode active material of a lithium ion battery, the high-temperature cycle performance of the battery can be improved while the high discharge capacity of the battery is ensured.