Electrodeposited Si film with excellent stability and high rate performance for lithium-ion battery anodes

Si film was prepared by electrodepositing on Ni substrate. SEM images and EDS analysis illustrated that the Si film was obtained successfully. The Si film anodes displayed a high reversible specific capacity (over 2800 mAhg ^{- 1}), an excellent stability (little fading after 80 cycles at a current of 0.36 Ag ^{- 1}, corresponding to 0.1 C), high rate performances (850 mAhg ^{- 1} at a current of 18 Ag ^{- 1}, corresponding to 5 C) and high electrochemical stability (The capacity was still more than 2600 mAhg ^{- 1}, when the current density returned to 0.36 Ag ^{- 1} after cycling at the high current densities). Electrochemical impedance spectroscopy tests showed that the Li ⁺ diffusion coefficient of the Si film was much higher than the pristine Si nanoparticles, which resulted in the high rate performances of the Si film.