Transforming of Rigid–Flexible Micro-Sized Silicon Anodes: Carbothermal Shock Method Yields Durable, High-Capacity Electrodes

Abstract

Silicon is considered as an ideal anode material for high-specific-energy lithium-ion batteries. However, developing silicon anode materials with long cycle life and low volume expansion remains challenging due to its drastic volume expansion. Herein, rigid-flexible Si@SiC@C composites are successfully synthesized via a scalable carbothermal shock method. Essentially, the silicon anode is stabilized by rigid SiC layer, which limits its volume increase and maintains electrode stability, while the nitrogen-infused carbon layer assists lithium-ion movement and improves electrode performance. This unique structural design makes Si@SiC@C electrode exhibit superior lithium storage performance, where it maintains a discharge capacity of 900.1 mAh g−1 after 1000 cycles at 1 A g−1, with a capacity retention rate of 89.3%. This work provides a pathway for the large-scale industrial preparation of silicon carbide and for designing high-performance silicon anode.