Lithium ion battery composite positive electrode material and preparation method thereof

Abstract

The invention discloses a lithium ion battery composite positive electrode material. The surface of the composite positive electrode material is coated with cerium and zirconium doped mesoporous aluminum phosphate and a graphene layer. The invention also discloses a preparation method of the material. The preparation method comprises the following steps of: adding 52-54% by mass of phosphoric acidinto an aluminum isopropoxide ethanol solution, adding a solution with zirconium and cerium concentrations of 0.1 mol / L and a surfactant, uniformly mixing, and regulating the PH value to 8.0-8.5 by using an alkaline complexing agent to prepare sol, and carrying out a hydrothermal reaction on the sol to obtain a precipitate, drying the precipitate, and carrying out heat preservation at 450-650 DEGC for 5-7 h to obtain the cerium and zirconium doped mesoporous aluminum phosphate powder. The lithium ion battery positive electrode material, the cerium and zirconium doped mesoporous aluminum phosphate powder, graphene, polyethylene glycol and N-methyl pyrrolidone according to a mass ratio of (40-100): (0.5-10): (0.1-10): (0.1-10): (50-200) are mixed uniformly, and the temperature of 450-550 DEG C in nitrogen for 3-5 hours is kept. The surface of the lithium ion battery composite material is coated with cerium and zirconium doped mesoporous aluminum phosphate, and the lithium ion battery composite material has good conductivity, stability and cycle performance.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a lithium ion battery composite cathode material and a preparation method thereof. Background technique [0002] Since Sony Corporation of Japan first successfully developed and commercialized lithium-ion batteries in 1991, lithium-ion batteries have attracted more and more attention. Lithium-ion batteries are widely used in the fields of consumer electronics, electric vehicles and energy storage devices because of their outstanding advantages such as high energy density, environmental friendliness, no memory effect, long cycle life, and small self-discharge. High specific capacity and energy density, good cycle stability and high safety. At present, the anode materials of lithium-ion batteries that have been applied in the market mainly include lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, and ternary cathode materials. Although lithium cobalt oxid...

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Problems solved by technology

Although lithium cobalt oxide has high capacity and long cycle life, its further development is limited due to the lack of cobalt resources and its toxicity; spinel materials such as lithium manganese oxide have low capacity and have not yet achieved major breakthroughs; lithium iron phosphate has low energy density , Poor conductivity, limited application in small cars; lithium manganate cathode materials still have problems such as low initial Coulombic efficiency and poor cycle performance, which limit the practical application of materials and their large-scale production

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