Pomegranate-like silicon-based anodes self-assembled by hollow-structured Si/void@C nanoparticles for Li-ion batteries with high performances.

Silicon is considered as one of the most promising alternatives to the graphite anode for lithium-ion batteries due to its high theoretical capacity (4200 mAh g). However, its fragile solid electrolyte interphase cannot tolerate the large volume changes of bare silicon induced by the lithium insertion and extraction, resulting in low Coulombic efficiency. In previous reports, a yolk-shell design, such as Si@void@C, in which the well-defined space allows the silicon particles to expand freely without breaking the outer carbon shells, can effectively improve the Columbic efficiency.