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

Transition metal oxide anode: This study is of mainly to shed the light on the research of ternary transition metal oxide nanocomposite materials for lithium-ion batteries. It also navigates the direction of research in improving the electrochemical performance of NiCo₂O₄.

Abstract

In 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.

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