High capacity performance of NiCo 2 O 4 nanostructures as a binder‐free anode material for lithium‐ion batteries

Summary Recently, binder‐free nanostructured materials provide a great opportunity for advanced lithium‐ion batteries (LIBs) owing to their improved electrical conductivity with good porous structure. NiCo 2 O 4 (NCO) nanostructures were successfully deposited on copper foam (CF) substrate to form porous three‐dimensional (3D) NCO@CF hybrid structures via a simple solvothermal synthesis, followed by further heat treatment at 300°C (designated as NCO@CF‐300) and 400°C (NCO@CF‐400). The as‐prepared samples revealed distinctly mixed morphologies of 2D nanosphere and nanowire‐like structures, tuned by the further heat treatment. Both the electrodes could be explored as a binder‐free anode for next‐generation LIBs. It is demonstrated that the good integration of 2D morphology of NCO with 3D architectured CF has a significant effect on its electrochemical results. For the first cycle, binder‐free NCO@CF‐300 and NCO@CF‐400 electrodes delivered the discharge capacity values of 1946 and 2637 mA h g −1 , respectively, at 500 mA g −1 . Moreover, the NCO@CF‐300 electrode exhibited stable reversible capacity and good rate capability. From these results, the growth of NCO nanostructures on the CF can be suggested as a potential anode material for high‐performance Li‐ion batteries.