A Core-Shell Si@NiSi₂/Ni/C Nanocomposite as an Anode Material for Lithium-ion Batteries

Highlights: • Si@NiSi₂/Ni/C nanocomposites with core-shell structure were synthesized via thermal reduction process. • Si@NiSi₂/Ni/C exhibited much higher capacities than Si/C and NiSi₂/Si anodes. • Si@NiSi₂/Ni/C anode displayed 98% capacity retention after 105 cycles. • Si@NiSi₂/Ni/C anode showed excellent rate capabilities. - Abstract: A Si-based alloy as the anode material in Li-ion batteries has advantages of safety and excellent performances, but poor electronic conductivity and excessive volume expansion limit the long cycle life required for practical application. In this work, in order to solve these problems, a core-shell nanocomposite has been developed, which is composed of a Si core and NiSi₂/Ni shell with a carbon layer coating as the outer surface, which is referred to as a Si@NiSi₂/Ni/C nanocomposite. Results show a reversible charge capacity of 1194 mA h g⁻¹ and 98% retention after 105 cycles, which are superior to its Si/C and NiSi₂/Si counterparts. Furthermore, the fabrication method used has advantages of low cost and easy operation, which make it feasible to commercialize the Si@NiSi₂/Ni/C nanocomposite as the anode in a lithium-ion battery.