A mechanical strategy of surface anchoring to enhance the electrochemical performance of ZnO/NiCo2O4@nickel foam 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, in order 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 and 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.

Graphical Abstract