Preparation method of lithium ion battery positive electrode material

Abstract

The invention relates to a preparation method of a lithium ion battery positive electrode material, and belongs to the technical field of lithium ion battery electrode materials. The method comprisesthe following steps: adding 50mg-200mg of ferric chloride hexahydrate, 5mg-40mg of nickel chloride hexahydrate and 3mg-20mg of carbon nanotubes into a mixed solvent consisting of water and DMF, adding1-5ml of a sodium sulfide solution with the concentration of 0.1 M into the mixed solution, carrying out heating reflux, transferring into a hydrothermal kettle, carrying out hydrothermal reaction toobtain a hydrothermal reaction product, and carrying out microwave plasma treatment. The FeNiS2-CNTs material prepared by the method has good chemical properties, more active sites are exposed due toa relatively large graphitization defect degree, and the preparation method is environment-friendly, simple and convenient for large-scale production.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a preparation method for a lithium-ion battery anode material-carbon nanotube material loaded with transition metal sulfides. Background technique [0002] In recent years, major breakthroughs have been made in the negative electrode materials of lithium-ion batteries. Compared with graphite carbon, the specific capacity of new silicon-based and tin-based materials has been significantly improved, while the development of positive electrode materials is relatively slow. Due to the limitation of the theoretical specific capacity of traditional cathode materials, it is urgent to find cathode materials with higher specific capacity. Sulfur is abundant in the earth and comes from a wide range of sources, so it can be used as a cathode material for lithium-ion batteries. Lithium-sulfur secondary batteries use metal lithium as the negative electrode and eleme...

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Problems solved by technology

[0005] Transition gold sulfide can be used as the positive electrode material of lithium-ion batteries, but it has certain disadvantages, such as certain expansion during charging and discharging, and poor cycle stability.

The reaction kinetics of this material is relatively poor, and the hysteresis phenomenon of charge and discharge is relatively serious.

There are three main reasons for the poor cycle stability of transition metal sulfides: the first is that the conductivity is poor, the diffusion coefficient of ions or electrons is not large, which reduces the reversibility of the electrode reaction, and the capacity decays quickly during cycling; the second is that transition metal sulfide materials Repeated reaction with Li produces pulverization, the electrical contact between the active particles, the collective flow and the active particles is lost, and the particles that lose contact no longer participate in the electrode reaction, and the capacity decays; the third is the transition metal sulfide material and Li The reaction produces metal nanoparticles, which agglomerate after many cycles, from less active material to capacity fading

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