Litchi-structural core–shell Si@C for high-performance lithium–ion battery anodes

Silicon is regarded as the next-generation alternative anode material of lithium–ion battery due to the highest theoretical specific capacity of 4200 mAh g−1. Nevertheless, the drastic volume expansion/shrink (~ 300%) during the lithiation/delithiation process and the poor electrical conductivity obstruct its commercial application. Herein, we report a novel design of litchi-structural Si@C nanoparticles (L-S Si@C) as long cycle life anode material for lithium–ion battery. The L-S Si@C with nanosized (~ 50 nm) SiC dispersed in the inner surface and ~ 6 wt% carbon layer covering the outer surface delivers a specific capacity of 1145 mAh g−1 in the initial cycle and maintains a specific capacity of 570 mAh g−1 after 300th cycling times, which can be attributed to the specially structurally stable L-S Si@C nanoparticles.