Method for preparing porous spherical Li(1-x)MxFe(1-y)Ny(PO4)([3+(alpha-1)x+(beta-2) y]/3)/C material

Abstract

The invention discloses a method for preparing a porous spherical Li(1-x)MxFe(1-y)Ny(PO4)([3+(alpha-1)x+(beta-2) y]/3)/C material, comprising the specific steps of: dissolving a lithium-containing compound, an iron-containing compound, a phosphor-containing compound and a element-doped compound additive in a dispersing agent to form a sizing agent; dispersing a mixture of a pore-forming agent, a cladding agent and a stabilizer in a dispersing agent through ultrasound, then adding into the sizing agent and mixing to form a new sizing agent; carrying out a physical method or a chemical method on the new sizing agent to obtain a sizing agent with the primary particles in nano grade; carrying out spraying drying and granulating on the obtained sizing agent with the primary particles in nano scale to obtain a dry mixed material with secondary particles with spherical appearances; then carrying out a sintering process on the dry mixed material to obtain the product of the invention. The method has the advantages that besides that the primary particles reach the nano scale, the particle diameters are more uniform in distribution and more regular in appearance, an iron phosphate product synthesized from the material has the particle diameters with uniform distribution, and the material has favorable processability, good electric conductivity, excellent power multiplication performance and higher actual capacity.

Description

technical field [0001] The invention relates to a preparation method of a positive electrode material of a lithium ion battery, in particular to a preparation method of a porous spherical lithium ion battery positive electrode material. Background technique [0002] Since 1990, Japan's Sony Corporation has adopted high-potential lithium cobaltate (LiCO) that can reversibly intercalate and deintercalate lithium ions. 2 ) as the positive electrode material, and lithium ion batteries have been developed, and the positive electrode materials for lithium ion batteries have developed rapidly. Cathode material LiCoO 2 It has been successfully commercialized, but the cost is prohibitive. LiNiO being extensively studied 2 , LiMn 2 o 4 Cathode materials have their own shortcomings: LiNiO 2 There are security issues, LiMn 2 o 4 The cycle and high temperature performance of LiFePO still need to be greatly improved, and the orthorhombic olivine-type LiFePO as a new lithium-ion ba...

AI Technical Summary

Problems solved by technology

Cathode material LiCoO 2 Already successfully commercialized, but cost prohibitive

LiNiO being extensively studied 2 , LiMn 2 o 4 Cathode materials have their own shortcomings: LiNiO 2 There are security issues, LiMn 2 o 4 The cycle and high temperature performance of LiFePO still need to be greatly improved, and the orthorhombic olivine-type LiFePO as a new lithium-ion battery cathode material 4 It has excellent electrochemical properties and is suitable as a cathode material for lithium-ion secondary batteries

[0004] (1) The electronic conductivity is low, and the diffusion rate of lithium ions in the electrolyte and materials is slow

[0005] (2) Low tap density of the product

[0006] (3) Poor processing performance

[0011] Chinese patent application number CN201010127068.8 discloses a preparation method of porous lithium iron phosphate, which uses high-speed stirring, sand milling or kneading as homogenization treatment means to homogenize raw materials, and essentially only uses physical grinding The method is to grind the raw materials to obtain the primary particles as nano-scale precursors. The nano-scale precursors of primary particles can also be prepared regardless of chemical methods, and the size distribution of primary particles prepared by physical methods is not uniform enough.

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