Continuous hydrothermal synthetic method for lithium ion cell nano anode material

Abstract

The invention discloses a continual hydrothermal synthesizing method of lithium ion battery nanometer anode, which comprises the following steps: adopting continual hyper (sub) clinical hydrothermal synthetic technique to make nanometer graded LiFePO4 particle through hypercritical flow transfer mass and crystallizing elementary; adding conductive material to make electrode material; spraying the product liquid into low-pressure flashing room with cyclone separator directly; gasifying water in the flashing room into steam; draining out from the top of cyclone separator; sedimenting solid particle on the bottom of flashing room; collecting dry powder as product.

Description

technical field [0001] The invention relates to a continuous hydrothermal synthesis method of nanometer cathode materials for lithium-ion batteries, which mainly adopts super (sub) critical hydrothermal crystallization synthesis technology to obtain lithium ferrous phosphate (LiFePO 4 ) and its modified lithium-ion battery cathode material nanoparticles. The invention belongs to the technical field of energy material preparation. Background technique [0002] Since the commercialization of lithium-ion batteries, cathode materials have always been a research hotspot in the field of batteries. Among them, LiCoO, the cathode material for lithium-ion batteries that has been industrialized 2 It pollutes the environment and is expensive, which greatly limits its future development. Lithium iron phosphate (LiFePO) with olivine structure 4 ) as a new type of lithium-ion battery cathode material has the advantages of wide material sources, low price, high theoretical specific cap...

AI Technical Summary

Problems solved by technology

Li Wei etc. adopt solid-phase synthesis method (Chinese patent, publication number CN1821064, the method for preparing high-density lithium iron phosphate by microwave heating) spherical high-density ferrous ammonium phosphate and lithium acetate are uniformly mixed with molar ratio 1: 1, add appropriate amount of carbon Source, drying, pressing, heating and calcining to obtain spherical lithium iron phosphate; although this method is simple to operate and convenient for industrial production, the reaction time is long, the material prepared at high temperature has a large particle size, and the mixing is uneven, and the electrochemical activity is insufficient; Zhu Bingquan et al. adopted the co-precipitation method (Chinese patent, publication number: CN1800003, a method for preparing lithium iron phosphate with olivine structure), and the divalent iron source compound, the phosphorus source compound and the oxidizing agent were prepared by LiFePO 4 The stoichiometric ratio is mixed, and the precipitated product is obtained by controlling the pH of the solution, and then a series of complicated steps such as filtration, washing, drying, and calcination are used to obtain LiFePO with a smaller particle size. 4

In summary, the current synthetic methods have certain shortcomings, or the quality of the obtained product is not high, the electrical activity is low, or the preparation steps are cumbersome, time-consuming, and energy-consuming.