Hedgehog-like polycrystalline Si as anode material for high performance Li-ion battery

A hedgehog-like Si nanomaterial has been prepared by metal assisted chemical etching method with polycrystalline Si powder as raw material and used as anode for lithium-ion batteries. The cycle stability and impedance are greatly enhanced compared with pristine silicon powder, and the Columbic efficiency (CE) keeps above 99.5% for up to 200+ cycles. The improved electrochemical characteristics are attributed to its volume buffering and effective conductance due to the unique structure, which combines nanowires on the surface and a core inside. The additives in electrolyte and suitable conductive materials help to stabilise the anode as well.