Carbon-Coated Porous Hollow Silicon Microspheres for High-Capacity and Durable Lithium Storage

Silicon-based materials are promising lithium-ion battery (LIB) anodes owing to their natural abundance and high capacity. However, their practical application is restricted by the poor electrical conductivity and large volume expansion. Herein, we successfully construct carbon coated porous hollow silicon microspheres (Si-40@C) as LIB anode materials, which are derived from the acid etching of commercial AlSi alloy with subsequent chemical vapor deposition carbon coating. The porous hollow structure of Si-40@C buffers the volume variation and promotes the transportation of Li+; the carbon coating enhances the overall conductivity as well as structural stability. The as-prepared Si-40@C porous hollow microspheres deliver a high reversible capacity (2029 mAh g(-1) at 0.2 A g(-1)), good cyclability (1668 mAh g(-1) after 100 cycles at 0.2 A g(-1)), and an ideal rate capability (1200 mAh g(-1) at 10 A g(-1)).