3D network electrodeposited nickel coatings on CuO nanorods with enhanced charge transport for high-rate Ni–Zn batteries

We report the nickel nanostructures electrodeposited with different morphologies to cover the nickel foam and copper oxide nanowire modified substrates. Our approach using different pulse-electrodeposition showed successful bottom-up growth of nanostructured materials ranging from dense rhombic pyramids to interlaced three-dimensional (3D) nanorod networks. The results revealed that the electrode comprised of electrodeposited nanocrystalline Ni films/CuO nanowires/copper foam featuring a 3D morphology provided a higher electrochemically active surface area, rapid redox kinetics, and highly reduced charge-transfer resistance (2.817 Ω). The quasi-solid-state Ni–Zn battery assembly using the 3D Ni electrode exhibited a significant performance over different charge and discharge current rates with particularly achieved maximum capacity of 110.9 mAh·g −1 at 5 mA cm −2 . This represents an enhancement of more than tenfold compared with Ni–Zn electrodes based on nanocrystalline nickel films. Transport of ions and electrons and multi-electron Ni redox with the O–O* intermediates with a defect-rich nanostructure from the pulsed reverse current (PRC) was the main reason for the improvement of performance. We are sure that the present work features a 3D design for high-kinetic Ni–Zn batteries.