Monocrystalline silicon nanowires and nanosheets as anodes of lithium-ion battery: Synthesis in mass production and low cost

Abstract

Monocrystalline silicon nanowires and nanosheets are prepared in mass production by the novel electroless etching method. Low-cost silicon powders are used as precursors. The initial capacities of silicon nanowires and nanosheets as lithium-ion battery (LIB) anodes are up to 4311 and 4426 mAh/g, respectively. After ten cycles, the reversible capacity maintains 2318 and 2791 mAh/g for nanowires and nanosheets, respectively. The capacity and cyclability of nanosheets is slightly higher than that of nanowires. Such a behaviour is attributed to their finite lateral sizes and enhanced open-edges, which can facilitate Li ion diffusion and decrease overvoltage associated with Li-Si alloying reaction. The presented results open a way for synthesising silicon nanostructures as LIB anodes in mass production and low cost. © The Institution of Engineering and Technology 2013.