Synthesis of core–shell architectures of silicon coated on controllable grown Ni-silicide nanostructures and their lithium-ion battery application

Abstract

Crystalline Ni₃Si₂ nanostructures were grown on nickel foams via a simple and high-yield chemical vapor deposition (CVD). The morphologies were found to be dependent on the growth pressure. The obtained nanostructures have good crystallinity and uniform distribution. After coating amorphous silicon (a-Si) layers onto the obtained Ni₃Si₂ nanostructures by an inductively coupled plasma CVD, the architectures were assembled as anodes for lithium-ion batteries. High initial reversible specific capacity of 3733 mA h g⁻¹ is obtained for the prepared a-Si coated Ni₃Si₂ nanowire electrode at a current density of 2.1 A g⁻¹. After 50 cycles, the specific capacity still stays at above 2000 mA h g⁻¹. When the current density is as high as 8.4 A g⁻¹, the specific capacity maintains at about 1500 mA h g⁻¹. For such core–shell configuration electrodes, the inactive and metallic Ni₃Si₂ core conducts electrons and provides a mechanically stable anchoring basis for the a-Si layers, resulting in improved electrochemical performance.