Highly ordered nanoporous Si for negative electrode of rechargeable lithium-ion battery

摘要

Highly ordered nanoporous Si was investigated as a rechargeable Li-ion battery anode. Hexagonally arranged nanoporous Si with a 200 nm hole interval was fabricated by direct nanoimprint and the subsequent galvanostatic etching in an aqueous HF solution. Hole size was controlled by changing current density, and larger holes (150 nm) showed higher anodic and cathodic charges during cyclic voltammetry. The use of nanoporous Si with large holes enabled galvanostatic cycling without the disintegration of nanoholes when charge capacity was set to 1400 mAhg~(-1). In the cycling, coulombic efficiency gradually improved and reached 96 at the last 20th cycle.