Electrodeposited Silicon Nanowires from Silica Dissolved in Molten Salts as a Binder-Free Anode for Lithium-Ion Batteries

Rational manipulation of size, surface chemistry, and electrode configuration is of prime importance to enhance lithium storage capability of silicon-based anode for Li-ion batteries. Herein, Si nanowires with small sizes (20–30 nm in diameter) and ultrathin surface oxide layer (∼1 nm in thickness) are directly electrodeposited on carbon cloth from soluble SiO2 in molten chloride salts. Benefiting from the small size, ultrathin oxide layer, and binder-free electrode configuration, the electrodeposited Si nanowires on carbon cloth therefore have a high initial Coulombic efficiency and a reversible capacity of 711 mAh g–1 after 200 galvanostatic charge/discharge cycles at 1000 mA g–1. The present study highlights that the molten salt electrolysis of soluble silica can be a customized preparation of Si for advanced Li-ion batteries.