Insights in Utilizing NiCo2O4/Co3O4 Nanowires as Anode Material in Lithium‐Ion Batteries

Abstract

AbstractIn this study, a facile and cost‐effective hydrothermal approach is employed to synthesize a mesoporous NiCo2O4/Co3O4 nanocomposite with nanowire morphology by using polyvinyl pyrrolidone as structure‐directing agent. The obtained NiCo2O4/Co3O4 nanocomposite shows better electrochemical performance than pure NiCo2O4 due to mainly two reasons: i) a strong synergistic effect between NiCo2O4 and Co3O4, which enhances the Li+ diffusion rate as well as lower the charge‐transfer resistance, and ii) the involvement of Co3O4 to contribute to the total capacity due to its high electrochemical activity. However, the performance of a NiCo2O4/Co3O4 nanocomposite electrode starts degrading after 400 cycles while pure NiCo2O4 maintains steady performance. Since the NiCo2O4/Co3O4 nanocomposite sample shows high porosity, it is believed that the obtained nanowire morphology cannot tolerate volume variations, which are generally triggered off during repeated Li+ (de‐)insertion at long‐term cycling. Therefore, the obtained results bring new insights in terms that there is a sweet spot between Li+ diffusion and high porosity in utilizing Co3O4 within a nanocomposite. This study is of guidance to shed the light on the research of ternary transition metal oxide nanocomposite materials for lithium‐ion batteries.