Preparation method of iron-sulfur negative electrode material for lithium battery

Abstract

The invention discloses a preparation method of an iron-sulfur negative electrode material for a lithium battery. The method comprises the following steps of preparing a high-performance iron-sulfur compound at a proper vulcanization sintering temperature by adopting ferrite hollow spheres with a special micro-nano structure, so that the iron-sulfur compound with relatively high crystallinity canbe obtained, and a lithium-storage reaction is facilitated; through carbon-nitrogen compounding, the conductivity of the active substance is improved; and in addition, a cavity between a nitrogen-doped carbon layer and the iron-sulfur compound provides an effective space for volume expansion in an active substrate intercalation / de-intercalation lithium process, so that pulverization agglomerationof the iron-sulfur compound is prevented.

Description

technical field [0001] The invention relates to the field of battery materials, in particular to a method for preparing an iron-sulfur negative electrode material for a lithium battery. Background technique [0002] In recent years, the domestic new energy automobile industry has developed rapidly, and there are various types of batteries. The market demand and requirements for batteries are gradually increasing. The key indicators it is most concerned about are mainly concentrated in five aspects: safety and stability performance, cycle life, wide temperature resistance, charging speed and energy density. [0003] Today, lithium-ion batteries play an increasingly important role in social development. Therefore, the development of high-performance, green and environmentally friendly electrode materials has become a research hotspot for lithium-ion batteries. At present, graphitized carbon materials are the main anode materials for lithium-ion batteries, but carbon material...

AI Technical Summary

Problems solved by technology

At present, graphitized carbon materials are the main anode materials for lithium-ion batteries, but carbon materials have the following shortcomings: (1) SEI film is formed during the first discharge process, causing irreversible capacity loss, and even causing internal structural changes and poor contact of carbon electrodes; (2) ) Due to the decomposition of the protective layer at high temperature, the battery will fail or cause a safety accident; (3) The capacity per unit volume is relatively low

However, iron-sulfur compounds as anode materials have disadvantages such as low electrical conductivity, polysulfides formed during the cycle are easily dissolved in the electrolyte, and the volume increases during the charge and discharge process, resulting in serious damage to the material structure, resulting in The stability and rate performance are poor, which greatly hinders their application in real life