Method for preparing lifexm1-xpo4/c lithium ion composite cathode material

Abstract

The invention discloses a method for producing an anode material for a lithium ion battery with low cost, which is characterized in that: a basic structural formula of the anode material for the lithium ion battery is LiFe[x]M[1-x]PO4, wherein the metallic element M can be manganese, cobalt, nickel, or mixture of manganese, cobalt, and nickel; and the anode material is presented as an olivine-shaped crystal structure and has higher discharge voltage platform and energy density than a LiFePO4 material. The method for producing the anode material comprises the following steps that: (1), a ferric salt, a metal M salt, and a soluble compound containing phosphate radicals are subject to reaction under an alkaline condition in the presence of water, water solution, or a solvent, so as to generate a precipitate, the precipitate is collected, cleaned and dried so that a nanoscale precursor containing iron and metal M is obtained; and (2), the nanoscale precursor is mixed with a lithium salt precursor, and then is mixed with a carbon precursor, the mixture is treated by nanocrystallization and drying, and then is roasted under an inert or reducing environment so as to generate the LiFe[x]M[1-x]PO4 / C composite anode material, wherein the x is valued between 0 and 1. The invention further aims to provide an electrochemically active anode material produced by the method with a low cost. The electrochemically active anode material can be applied to producing electrodes and batteries.

Description

technical field [0001] The invention relates to the field of a secondary battery, in particular to a preparation method of an active positive electrode material for a lithium ion battery containing iron, manganese (cobalt or nickel) and phosphate, and a corresponding electrode and battery. Background technique [0002] Various positive electrode materials have been investigated in the field of rechargeable batteries. LiCoO 2 Due to its high working voltage and long cycle life, it has become the most commonly used cathode material in commercial lithium-ion batteries. Although LiCoO 2 It is a widely used cathode material in portable rechargeable battery applications, but its high cost, high toxicity, and relatively low thermal stability make it severely limited as a cathode material for rechargeable batteries. These limitations have prompted many studies examining the methods used to process LiCoO 2 to improve its thermal stability. However, the safety issue due to low th...

AI Technical Summary

Problems solved by technology

In most of these existing technologies, the compound precursors containing iron, manganese, lithium and phosphate are directly activated by mechanical blending and solid-state reaction to generate active materials. This manufacturing method is still limited by the long mixing time of the precursors. And uneven, the stoichiometric ratio of each active ingredient is difficult to control due to the inevitable loss during the mixing process, resulting in poor performance of the battery material

While the sol-gel method (J.-K.Kim et al. / Journal of Power Sources189(2009)391–396) can achieve the advantages of uniform mixing, the complexity of the process and the high cost of raw materials and processes are not sufficient. suitable for industrialization

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