High-first-effect multi-element coated silicon-based composite material as well as preparation method and application thereof

Abstract

The invention relates to the field of silicon-based materials, in particular to a preparation method of a high-first-effect multi-element coated silicon-based composite material. The method comprisesthe following steps: (1), uniformly mixing and dispersing nano silicon, a dispersing agent, metal powder and a binding agent in an organic solvent to obtain a precursor A; (2), performing high-temperature treatment on the precursor A to obtain a precursor B; (3), enabling the precursor B to be subjected to acid pickling, filtering and drying treatment, and obtaining a precursor C; and (4), carrying out carbon coating on the precursor C to obtain the high-first-effect multi-element coated silicon-based composite material. According to the high-first-effect multi-element coated silicon-based composite material as well as the preparation method and application thereof, the process is simple and feasible, the product performance is stable, and the composite material has a good application prospect.

Description

technical field [0001] The invention relates to the field of silicon-based materials, in particular to a high-first-efficiency multi-component coated silicon-based composite material, its preparation method and its application. Background technique [0002] At present, commercial anode materials are mainly natural graphite, artificial graphite and intermediate equivalent graphite materials, but due to their low theoretical capacity (372mAh / g), they cannot meet the market demand. In recent years, people have focused on new high-capacity anode materials: lithium storage metals and their oxides (such as Sn, Si) and lithium transition metal phosphides. Among many new high-capacity negative electrode materials, Si has become one of the most potential alternative graphite materials due to its high theoretical specific capacity (4200mAh / g), but silicon-based has a huge volume effect during charge and discharge. , easy to crack and pulverize, thus losing contact with the current co...

AI Technical Summary

Problems solved by technology

The harsh conditions of chemical synthesis make it difficult to prepare nano-silicon on a large scale.

The process of preparing nano-silicon by physical ball milling inevitably results in a thick oxide layer on the surface of nano-silicon, which affects the first-time efficiency of the material.

Images