Synthesis of NixSiy-SiGe core-shell nanowire arrays on Ni foam as a high-performance anode for Li-ion batteries

We demonstrate the large-area synthesis of NixSiy-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 NixSiy-SiGe nanowire arrays show high reversible capacity and good rate capability compared to planar SiGe layers and NixSiy-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.