Efficient electrochemical performance of MnO₂ nanowires interknitted vanadium oxide intercalated nanoporous carbon network as cathode for aqueous zinc ion battery

Rechargeable aqueous Zn-ion batteries (AZIBs) have emerged as promising large-scale energy storage devices because of their low cost and good safety characteristics. Vanadium oxide-based materials have been actively studied as future cathode materials for AZIBs, benefiting from their suitable voltage and high specific capacity. However, poor rate performance and capacity deterioration due to the instability of their oxides is still a hurdle in their commercialization. Herein, we attempted to test a methodology involving the carbonization of V-MIL-101 to prepare a composite material consisting of vanadium oxide nanoparticles embedded within the nanoporous carbon network, which remarkably enhances the electrochemical performance of the material as a cathode in an aqueous Zn-ion battery system. The manganese oxide loading further stabilized the composite material, which improved the cathode material's rate capability in aq. zinc ion battery cathode. The cathode material MnO₂@NVC composite exhibited the capacity of 299 mAhg⁻¹ at 0.1C rate for 100 cycles benefitting from the synergistic effect of the high conductivity of Vanadium oxide nanoparticles and suitable voltage of MnO₂. The materials showed superior capacity retention and better cycling performance than unmodified vanadium oxide nanoparticles on carbon substrate as cathode material. The comparative morphological and electrochemical studies confirm the improved performance, which suggests that the vanadium oxide nanoparticles anchored on a high surface area carbon network intertwined with manganese oxide nanowires provide enhanced conductivity.