Preparation method of anode material vanadium-lithium phosphate powder for lithium ion battery

Abstract

The invention relates to a preparation method of anode material vanadium-lithium phosphate powder for lithium ion battery, belonging to the technical field of battery material. The preparation method provided in the invention is implemented by homogenizing raw materials followed by secondary drying to obtain a precursor, heating at 550-1000 DEG C in non-oxide atmosphere to prepare vanadium-lithium phosphate powder. In the method, the precursor homogenized on micro-scale is prepared by secondary drying, raw materials can be mixed on molecular level of the solution, all the elements are uniformly mixed, thus avoiding composition segregation, ensuring super close contact among raw materials, overcoming the defect of incomplete contract of raw materials in solid phase technique and greatly reducing reaction activation energy; the whole process dispenses with procedures of grinding, pre-treating, crushing and the like, the prepared material has higher specific discharge capacity and capacity retention rate, and the method is simple in technique, continuous in operation and easy for industrial production.

Description

technical field [0001] The invention relates to the technical field of battery materials, in particular to a preparation method of positive electrode materials for lithium ion batteries. Background technique [0002] Lithium-ion battery is a new generation of secondary battery after nickel-cadmium and nickel-metal hydride batteries. The main factors affecting the performance of lithium-ion batteries are: positive electrode materials, negative electrode materials, electrolytes, separators, etc., and positive electrode materials are very important for improving the working voltage, specific energy, cycle life and other important properties of lithium-ion batteries. [0003] Currently commonly used is LiCoO 2 , LiMn 2 o 4 and LiNiO 2 . However, the lack of cobalt resources limits the LiCoO 2 Applications of LiNiO 2 Difficult to synthesize, there is an obvious exothermic reaction during charging and discharging, which may cause safety problems, LiMn 2 o 4 When working n...

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Problems solved by technology

[0010] The purpose of the invention is to overcome the current preparation of Li 3 V 2 (PO 4 ) 3 When it is necessary to ball mill the raw material and then dissolve it with hot water, and the precursor needs to be pretreated before roasting, and the roasted product needs to be coated and fused after roasting. There are many steps, and it is not easy for industrial production. A lithium-ion The preparation method of lithium vanadium phosphate powder used as a positive electrode material for batteries, this method overcomes the defect that the raw materials cannot be fully contacted in the solid phase method, mixes the raw materials at the molecular level of the solution, and removes the solvent on this basis, after two Sub-drying can produce a homogeneous precursor on the microscopic scale. By adjusting the composition and structure of the material, the segregation of the composition is avoided, the ultra-close contact between the raw materials is ensured, and the activation energy of the reaction is greatly reduced. The whole process does not require grinding. , pretreatment and crushing processes, the prepared material has high purity, good dispersibility, uniform particle size, high discharge specific capacity and capacity retention rate, and is obtained by secondary spray drying under the same charge and discharge conditions The discharge capacity of the product after the heat treatment of the precursor is greater than that of the product after the heat treatment of the precursor obtained by one-time spray drying, and this method is simple in process, can be operated continuously, and is easy for industrial production

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