Method for preparing lithium vanadium phosphate and lithium manganese phosphate composite anode material through rheological phase reaction

Abstract

The invention discloses a method for preparing a lithium vanadium phosphate and lithium manganese phosphate composite anode material through rheological phase reaction, which comprises the following steps: uniformly mixing ammonium metavanadate, manganese salt, phosphate salt, polyethylene glycol and lithium salt dissolved into water, reacting for 5-10 hours in constant-temperature water bath of 75-95 DEG C to form a rheological jelly and calcining the dried rheological jelly for 10-20 hours in the non-oxidizing atmosphere of 650-800 DEG C, namely Li3V2 (PO4)3.LiMnPO4. The invention has the beneficial effects that the method is simple and convenient, is easy to control and low in cost; the synthesized Li3V2 (PO4)3.LiMnPO4 composite material overcomes the defect of low electronic conductivity of a monomer material Li3V2 (PO4)3 and low ion diffusion rate, low ion conductivity and difficulty in synthesis of a monomer material LiMnPO4; and compared with the monomer materials, the charge and discharge performance and the cycling performance of a sample are respectively improved.

Description

technical field [0001] The invention relates to a method for preparing lithium vanadium phosphate and manganese lithium phosphate composite materials by rheological phase reaction. Background technique [0002] Due to its high performance and high stability, lithium-ion batteries play a pivotal role and status in the fields of electronic information, new energy, electric vehicles (EV) and hybrid electric vehicles (HEV), and environmental protection. Therefore, exploring lithium-ion batteries with excellent performance Battery cathode materials have broad and deep meanings. A.K.Padhi et al. believe that Li with NASCION structure 3 V 2 (PO 4 ) 3 It is one of the positive electrode materials for lithium-ion batteries with great development potential. Li 3 V 2 (PO 4 ) 3 It has the advantages of stable structure, high working potential (3.6-4.5V, vs. Li / Li+), high theoretical specific capacity (197mAh / g) and good reversibility of rapid charge and discharge. However, the...

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Problems solved by technology

But LiMnPO 4 The ion diffusion rate in the material is small, and its own ionic conductivity is low, making it difficult for lithium ions to intercalate and extract normally in the material, so LiMnPO with electrochemical activity 4 Materials are difficult to synthesize

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