Iron Oxide Shell Coating on Nano Silicon Prepared from the Sand for Lithium-Ion Battery Application

Elemental silicon, due to its high specific capacity (4200 mAh g(-1)) and non-toxicity is expected to be an attractive anode material for Li-ion battery. But its huge expansion volume (>300%) during charging of battery, leads to pulverization and cracking in the silicon particles and causes sudden failure of the Li-ion battery. In this work, we have designed yolk-shell type morphology of silicon, prepared from carbon coated silicon nanoparticles soaked in aqueous solution of ferric nitrate and potassium hydroxide. The soaked silicon particles were dried and finally calcined at 800 degrees C for 30 minutes. The product obtained is deprived of carbon and has a kind of yolk-shell morphology of nano silicon with iron oxide coating (Si@Iron oxide). This material has been tested for half-cell lithium-ion battery configuration. The discharge capacity is found to be approximate to 600 mAh g(-1) at a current rate of 1.0 A g(-1) for 200 cycles. It has shown a stable performance as anode for Li-ion battery application.