Binder and conductive additive-free NiO nanorod electrodes prepared by the sputtering method for Li-ion battery anodes with an ultra-long life cycle

NiO nanostructures and film were deposited on Cu foil using radiofrequency (RF) magnetron sputtering with oblique and glancing angle deposition technology. The modified CU foil was used as an anode material for a Li ion battery without binder or conductive additives. The electrochemical properties of the NiO electrodes depended on their porosity, which varied with the angle of incidence of the target with respect to the normal substrate surface. The NiO electrodes showed a well aligned nanorod structure when deposited at a glancing angle of 85 degrees. The optimal NiO nanorod electrodes exhibited a reversible lithium capacity of 710 mAh g(-1) at a current rate of 0.5C and 270 mAh g(-1) at a current rate of 20 C. Furthermore, after 1000 ultra-long cycles at 2.0C, the capacity of the NiO nanorod electrode was retained at about 500 mAh g(-1), which was similar to 70% of theoretical capacity. The high performance and ultra-long life cycle of the NiO nanorod electrodes was attributed to super-structures with macroporosity.