Co-doped NiO nanoflake arrays toward superior anode materials for lithium ion batteries

• Published in: Journal of power sources 2011-08, Vol.196 (15), p.6388-6393
• Main Authors: Mai, Y.J., Tu, J.P., Xia, X.H., Gu, C.D., Wang, X.L.
• Format: Article
• Language: English
• Subjects: Applied sciences; Array film; Arrays; Cobalt; Contact; Diffusion rate; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; Electronic conductivity; Exact sciences and technology; Lithium ion battery; Lithium-ion batteries; Materials; Metal-doping; Nanocomposites; Nanomaterials; Nanostructure; Nickel oxide
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.03.089

► In this paper, we attempt to address the poor kinetics of conversion reactions, the major drawback for it, by synchronously considering optimization design of electrode configuration and improvement of the lattice electronic conductivity of active materials. Results suggest Co-doped NiO nanoflake arrays electrode show high capacity, good cycling performance and rate capability. These can be attributed to the synthesis effect, coming from high electrode–electrolyte contact area, direct contact between each naonflake and current collector, fast Li+ diffusion and improvement of p-type conductivity of active materials. Co-doped NiO nanoflake arrays with a cellular-like morphology are fabricated by low temperature chemical bath deposition. As anode material for lithium ion batteries (LIBs), the array film shows a capacity of 600mAhg−1 after 50 discharge/charge cycles at low current density of 100mAg−1, and it retains 471mAhg−1 when the current density is increased to 2Ag−1. Appropriate electrode configuration possesses some unique features, including high electrode–electrolyte contact area, direct contact between each naonflake and current collector, fast Li+ diffusion. The Co2+ partially substitutes Ni3+, resulting in an increase of holes concentration, and therefore improved p-type conductivity, which is useful to reduce charge transfer resistance during the charge/discharge process. The synergetic effect of these two parts can account for the improved electrochemical performance.