Preparation of hard carbon–coated and metal-modified silicon anode materials for lithium-ion batteries

Abstract

High-capacity silicon anode is one of the ideal anode materials for the next generation, but the volume expansion effect and low conductivity hinder its development. In this study, a simple and low-cost method was employed to prepare micron-sized silicon raw materials. Subsequently, a hard carbon-coated structure was combined with the metal modification method to successfully prepare hard carbon–coated silver-modified silicon particle material. Due to the hard carbon coating structure, Si/Ag@HC materials can effectively alleviate the volume expansion of silicon, and the modification of metallic silver can not only improve the conductivity of silicon, but also further enhance the ability to limit the volume expansion effect. The Si/Ag@HC maintains a specific capacity of 997.05 mAh g⁻¹ after 200 cycles at a current density of 0.5C, and it also shows an excellent rate performance of over 600 mAh g⁻¹ at a current density of 2C.