Growth of nanostructured nickel sulfide films on Ni foam as high-performance cathodes for lithium ion batteries.

We report a facile and reproducible synthesis of nanostructured Ni3S2 films by a hydrothermal route with Ni foam as the precursor reactant and substrate. The synthetic mechanism was examined by investigating the dependence of the films' crystal morphologies on the hydrothermal duration, and uniform nanostructured Ni3S2 films with a porous carpet-like morphology were synthesized on the substrates. The architectures were used as cathodes for lithium ion batteries (LIBs), and their electrochemical performances were evaluated as a function of the film thickness. The first discharge and charge capacities were 596 and 466 mA h g(-1) for the electrode with an optimal film thickness and a higher reversible capacity of 421 mA h g(-1) was obtained after 60 cycles at a current density of 50 mA g(-1). The simplicity of the synthetic methodology and the better electrochemical performance make the synthesized Ni3S2 films a promising cathode material for next-generation LIBs.