Electrodeposition of silicon nanospheres on rGO coated copper substrate for lithium-ion batteries

Abstract

In the present work, the electrodeposition of silicon nanospheres was carried out from water contaminated room temperature ionic liquid medium on the reduced graphene oxide (rGO) coated copper (Cu) substrates. The graphene oxide coated copper was reduced in hydrogen: argon mixture to obtained rGO coated copper substrate which was used for electrodeposition of silicon nanospheres. The silicon nanospheres were electrodeposited using 1 M SiCl4 in water contaminated 1-Butyl-3-Methylimidazolium-bis (Trifluoromethylsulfonyl) imide (BMImTf2N) ionic liquid at −1.5 V (vs. Pt). The X-ray diffraction (XRD) patterns at 44.8˚, 51.42˚, 75.12˚, and Raman peak at 521 cm−1 confirm the deposition of elemental silicon. The field emission scanning electron microscopy (FE-SEM) images show the electrodeposited silicon nanospheres of average particle size 125 nm. Further, the electrochemical measurements were carried out to explore the performance of the active material as a negative electrode in Li-ion batteries. The reversible specific capacity of electrodeposited Si nanospheres is obtained as 294 mAhg−1 at current density 250 µA cm−2.