Nanostructured NiSi thin films as a new anode material for lithium ion batteries

Nanostructured NiSi thin films have been successfully fabricated by pulsed laser deposition. Their lithium electrochemical properties have been investigated by charge/discharge measurement and cyclic voltammograms. A large reversible specific capacity of 1220 mAh/g was found with excellent capacity retention. Ex situ HRTEM and SAED data have demonstrated that the electrochemical reaction mechanisms of nanostructured NiSi with lithium involve the reversible transformation between NiSi and Ni/Li22Si5. The results implied that Ni could be an “active” participant in the electrochemical reactions of NiSi alloy with lithium but not only an inactive volume change buffer. This kind of structural reversibility should be responsible for its excellent electrochemical performance.

Research Highlights► In this paper, we fabricated nanostructured NiSi thin films by pulsed laser deposition. ► We examine their lithium electrochemical properties by charge/discharge measurement and cyclic voltammograms. ► We found a large reversible specific capacity of NiSi thin film electrode of 1220 mAh g–1 with excellent capacity retention. ► The electrochemical reaction mechanisms of the nanostructured NiSi with Li involve reversible transformation between NiSi and Ni/Li22Si5 during discharge and charge. ► This kind of reversible phase transition should be responsible for its good electrochemical performance.