An amorphous Si material with a sponge-like structure as an anode for Li-ion and Na-ion batteries

Sponge-like amorphous silicon was prepared by reacting silicon tetrachloride with magnesium powder. When the as-prepared sample was applied as an anode in rechargeable batteries, it exhibited a reversible capacity of 1125 mA h g-1 after 100 cycles at 1 A g-1 for Li-ion batteries (LIBs) and a reversible capacity of 176 mA h g-1 at 100 mA g-1 over 100 cycles for Na-ion batteries (NIBs).