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

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. (C) 2013 Elsevier B.V. All rights reserved.