Abstract: Silicon (Si)-based anode materials of Li-ion batteries have attracted extensive attention owing to their high theoretical specific capacity (4200 mAh·g⁻¹), low working potential, abundant resources, and environmental friendliness. However, Si undergoes a volume expansion of approximately 400% during lithiation, which readily leads to electrode cracking and pulverization. This study proposes a doping-etching-reconstruction strategy utilizing cobalt-based zeolitic imidazolate framework (ZIF-67) as a sacrificial template to synthesize cobalt-iron layered double hydroxides (LDHs), fabricating a composite silicon-based anode material with a hollow structure (Si@CoFeO_x). This material maintains a reversible specific capacity of 952.6 mAh·g^-1 after 600 cycles at a current density of 1 A·g^-1, and retains a specific capacity of 427.7 mAh·g^-1 after 400 cycles at a high current density of 2 A·g^-1. The superior electrochemical performance of this composite is primarily attributed to its hollow structure, which effectively accommodates the volume expansion of silicon nanoparticles during cycling. This study provides insights into the structural design of high-performance Si-based anode materials for lithium-ion batteries.

Key words: silicon-carbon composite anode, Li-ion battery, hollow structure, high electrical conductivity, ZIF-67, LDHs