Synthesis of porous NiO materials with preferentially oriented crystalline structures with enhanced stability as lithium ion battery anodes

•Porous NiO with preferentially oriented structure is synthesized through cathodic deposition.•Agarose gel is used as a meditative template and conductive carbon sources.•The composite films exhibit an enhanced reversible capacity and cycling stability as anode materials.•The improvement is ascribed to the synergetic effects of unique structure between porous NiO and carbonaceous matrix.

A simple strategy is described for the synthesis of nickel oxide embedded in a carbonaceous matrix (NiO/C) using a templated agarose gel thin film, in an attempt to produce an electrode with a large reversible capacity and long cycle stability. The as-prepared films are directly deposited onto stainless steel substrates from a solution of the Ni2+ precursors. Scanning electron microscopy images indicate that the as-synthesized NiO/C has a porous and interconnected structure. The results of X-ray diffraction and Fourier transform-infrared spectroscopy analyses confirm the preferential (111) growth of NiO and the presence of carbonaceous materials. As an anode material for lithium ion batteries, this novel structure plays a positive role in producing a material with a large reversible capacity, high conductivity, and long cyclic stability. The high reversible capacity is maintained at an elevated current density. Even after 100 cycles, the NiO/C anodes deliver more than 600 mAh g−1 at a current density of 718 mA g−1, which is significantly higher than the capacity of commercial graphite anodes. The results indicate the existence of a synergetic effect between the porous NiO layers and the conductive matrix in the composite.

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