A Novel Ni-doped ZnMn2O4/Mn2O3 nanocomposite synthesized by pulsed potential as superior zinc ion battery cathode material

Abstract

The research and development of suitable cathode materials for Zn2+ storage is crucial to meet the large-scale energy storage application of zinc-ion batteries (ZIBs). However, manganese-based oxide cathodes, the most-studied category of cathode materials, suffer from capacity decline and weak electrical conductivity. Herein, Ni-doped ZnMn2O4/Mn2O3 nanocomposite has been synthesized using pulsed potential electrodeposition technique and then applied as cathode material for ZIBs. The Ni2+ doping effectively boosts the electrical conductivity and electrochemical performance of electrodes. Furthermore, simultaneous production of ZnMn2O4 /Mn2O3 nanocomposite as a two-phase compound and incorporation of Ni2+ in crystal structure leads to an improvement in reversibility and cyclability of Ni-doped ZnMn2O4/Mn2O3 nanocomposite. Moreover, the Ni-doped ZnMn2O4/Mn2O3 nanocomposite presents a specific capacity of 235.10 mAh g−1 (0.2 A g−1), higher than Undoped nanocomposite (215 mAh g−1). Besides, the Ni-doped ZnMn2O4/Mn2O3 nanocomposite shows superior electrochemical performance, with a reversible capacity of 114.67 mAh g−1 and capacity retention of 91.32%, obtained after 3000 cycles at 2 A g−1, while the Undoped -ZnMn2O4/Mn2O3 nanocomposite possesses the capacity of 61.85 mAh g−1 with 64.54% capacity retention at the same condition. The obtained results suggest that the synergistic effect of doping and two-phase compound synthesis provide new features for the practical application of ZIBs.