Novel silicon/copper nanowires as high-performance anodes for lithium ion batteries

Si/Cu/Zn ternary microspheres are prepared by a pulsed electrical discharging method in a scalable manner. Zn and partial Si within these microspheres can then be selectively removed by chemical etching to form Si/Cu nanowires. The Si/Cu (~62 atom% Si) nanowires show a high discharge capacity of 2092 mAh g⁻¹ and a high capacity retention after 500 cycles at a current density of 200 mA g⁻¹. The excellent rate and cycling performance are attributed to the conductive Cu network and nanowire structure, which increases the electric conductivity of the electrode and accommodates the volumetric change of silicon during the charge/discharge process. Furthermore, the Si/Cu nanowire anode utilizes relatively cheap materials and flexible processing methods, costing approximately $0.3 g⁻¹. This work presents a novel method to prepare nanowire-like Si-based anode materials, which is promising to boost the yield of Si alloy NWs with low cost.