Preparation method of lithium ion battery electrode material

Abstract

The invention provides a preparation method of a lithium ion battery electrode material. The preparation method comprises the following steps: adding a carbon source and any two of a boron source, a sulfur source and a nitrogen source of a nonmetallic doping raw material as dispersoids into a dispersant, and uniformly stirring the materials to form a first mixture; adding a lithium source, an ironsource and a phosphorus source to the first mixture, or adding a lithium source, an iron source, a manganese source and a phosphorus source, or adding a lithium source and a titanium source to form asecond mixture; stirring and heating the second mixture until the solution is evaporated to form a solid to obtain a precursor of a nonmetallic co-doped carbon-coated electrode material; drying the solid in vacuum, heating the solid to 250-450 DEG C under an inert gas atmosphere, heating the solid at a constant temperature for 3-5h, and cooling and grinding the solid to obtain a reaction precursor; and heating the reaction precursor to 700-1000 DEG C under an inert gas atmosphere, calcining the reaction precursor at a constant temperature for 8-30h, and carrying out grinding and sieving aftercooling to obtain the lithium ion battery electrode material.

Description

Technical field [0001] The present invention relates to the technical field of lithium-ion battery electrode materials, and specifically relates to a method for preparing a non-metallic element co-doped carbon-coated lithium-ion battery electrode material and an electrode material prepared by the method. Background technology [0002] Currently, lithium-ion batteries are widely used in various mobile electronic products and new energy vehicles. These include lithium cobalt oxide (LiCoO 2 ), lithium nickelate (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), lithium iron manganese phosphate (LiFe 0.5 +xMn 0.5 -xPO 4 ), lithium iron phosphate (LiFePO 4 ) cathode materials and graphite, lithium titanate (Li 4 Ti 5 O 12 ) is the most commonly used negative electrode. Among them LiCoO 2 It is expensive, has high cost, lacks Co resources, and is highly toxic; LiNiO 2 Poor thermal stability and poor safety; LiMn 2 O 4 Although it has good safety performance, its capacity ...

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Problems solved by technology

However, due to the limitation of the material synthesis temperature (650-1000°C), the carbon coating layer in method 1) is mainly composed of amorphous carbon. Compared with highly graphitized graphene and carbon nanotubes, the amorphous carbon The electronic conductivity is relatively low. Therefore, it is far from meeting the needs of future battery development to improve the electronic conductivity of the electrode material only by the amorphous carbon coating layer.

At present, the most direct and effective way is to increase the sintering temperature (≥1800°C) to increase the degree of graphitization of the carbon layer, but this method consumes a lot of energy, and the high sintering temperature will deform the structure of the electrode material and even deactivate it.

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