A mechanical strategy of surface anchoring to enhance the electrochemical performance of ZnO/NiCo2O4@NF self-supporting anode for lithium-ion batteries

Abstract NiCo₂O₄ has the advantages of high energy density, low cost, and environment-friendly as the anode materials of lithium-ion batteries. However, NiCo₂O₄ is adversely affected by the slow transmission rate of lithium-ion and the collapse of its three-dimensional loose and porous nano-flake structure causes its poor cycling performance. In this study, to address this issue, the NiCo₂O₄ @ nickel foam(NF) composite was formed by depositing ZIF-67 on nickel foam through room temperature standing and 350 ℃ treatment, and then short ZnO nanorods with an anchoring structure were grown on its surface through heat treatment and hydrothermal treatment to obtain ZnO/NiCo₂O₄@NF compound materials. The nano-rod structure of ZnO material increases the contact between the electrode material and electrolyte, reduces the charge transfer resistance, and its anchoring structure stabilizes the porous sheet architecture of NiCo₂O₄@NF. After 100 cycles (100 mA∙g⁻ ¹), the discharge capacity of the ZnO/NiCo₂O₄@NF composite electrode remained at 475.2 mAh∙g⁻ ¹, which is significantly higher than 313.8 mAh∙g⁻ ¹ of NiCo₂O₄@NF electrode and 245.4 mAh∙g⁻ ¹ of ZnO@NF electrode.