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

Abstract In this study, a facile and cost‐effective hydrothermal approach is employed to synthesize a mesoporous NiCo 2 O 4 /Co 3 O 4 nanocomposite with nanowire morphology by using polyvinyl pyrrolidone as structure‐directing agent. The obtained NiCo 2 O 4 /Co 3 O 4 nanocomposite shows better electrochemical performance than pure NiCo 2 O 4 due to mainly two reasons: i) a strong synergistic effect between NiCo 2 O 4 and Co 3 O 4 , which enhances the Li + diffusion rate as well as lower the charge‐transfer resistance, and ii) the involvement of Co 3 O 4 to contribute to the total capacity due to its high electrochemical activity. However, the performance of a NiCo 2 O 4 /Co 3 O 4 nanocomposite electrode starts degrading after 400 cycles while pure NiCo 2 O 4 maintains steady performance. Since the NiCo 2 O 4 /Co 3 O 4 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 Co 3 O 4 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.