Multiwall Carbon Nanotubes Interlinked Nickel Preintercalated Vanadium Oxide Composites for Chemically Self-Charging Aqueous Zinc-Ion Batteries

Self-charging energy-storage devices, through the synergistic combination of ambient electrochemical storage and energy harvesting, have emerged as a rapidly developing frontier in sustainable energy research. Herein, carbon nanotubes interlinked nickel preintercalated vanadium oxide is successfully fabricated (denoted as NiVO/CNTs), serving as cathode electrodes for chemically self-charging aqueous zinc-ion batteries (AZIBs). Notably, the preintercalated Ni ions and crystal water are essential for enhancing the structural stability and the spontaneous redox reactions relatively. In addition, the incorporation of CNTs acts as both a charge-transfer medium and a spatial expansion material to optimize electrochemical performance by constructing conductive networks and enhancing electrode/electrolyte contact areas. The NiVO/CNTs demonstrate exceptional electrochemical activity, with specific capacities (218.5 mAh g^-1 after 150 cycles at 1 A g^-1) and outstanding cycling performance (68.1 mAh g^-1 following 5000 cycles at 5 A g^-1). More importantly, NiVO/CNTs exhibit excellent chemical self-charging capabilities (specific capacity of 180.8 mAh g^-1 and resting voltage of 0.96 V). This work promotes the development of AZIBs while expanding the potential utility of vanadium-based oxide cathode materials in chemically self-charging systems.