Synthesis of Ni sub(x)Si sub(y)-SiGe core-shell nanowire arrays on Ni foam as a high-performance anode for Li-ion batteries

We demonstrate the large-area synthesis of Ni sub(x)Si sub(y)- SiGe core-shell nanowire arrays on a Ni foam via chemical vapor deposition and subsequent co-sputtering methods. When used as the anode of Li-ion batteries, the Ni sub(x)Si sub(y)-SiGe nanowire arrays show high reversible capacity and good rate capability compared to planar SiGe layers and Ni sub(x)Si sub(y)-Si core-shell nanowires. The good adhesion and contact of the core-shell nanowires with the current collector, and the integration of Ge which can greatly improve the conductivity and lithium-ion-diffusivity in the SiGe layer, may be responsible for the enhanced performance.