Carbon/binder free 3D Si@Cu2O anode for high performance lithium ion battery

Abstract

A liquid-phase reduction method was applied to the synthesis of Cu2O microspheres as a 3D array current collector. An active silicon film with a tunable thickness was then deposited on the 3D Cu2O microspheres by magnetic sputtering as the carbon/binder free anode for lithium ion battery (LIB). As a comparison, Si-Cu2O composite electrode was also prepared via a solvothermal method. The specific capacity of Si@Cu2O-15 anode gradually decreased from 1596.8 mA h.g–1 to 1526.9 mA h▪g–1 after 100 cycles with an average loss of specific capacity at 0.24% per cycle. Moreover, the coulomb efficiency of the electrode remained at about 98%. Furthermore, the reversible capacity of the Si@Cu2O-15 anode still maintained above 709.0 mA h.g–1 after 60 cycles at a higher rate of 2 C, being ascribed to the improved diffusion rate of charge at the solid-liquid interface and to the collection efficiency of electrons in the 3D current collector, which was higher than that of Si-Cu2O composite anode (remained as 448 mA h.g–1 after 60 cycles at 2 C).