Hierarchical amorphous vanadium oxide and carbon nanotubes microspheres with strong interface interaction for Superior performance aqueous Zinc-ion batteries.

Aqueous zinc-ion batteries have attracted more and more attention due to their safety, environmental benignity and high theoretical capacity. However, the lack of appropriate cathode materials with high capacity and long cycle life have become an obstacle to the development of aqueous zinc-ion batteries. Herein, the hierarchical amorphous vanadium oxide and carbon nanotubes (a-V2O5@CNTs) microspheres with strong interface interaction were successfully prepared by combing facile spray drying technique with annealing treatment. Benefiting from the a-V2O5 amorphous characters, CNTs framework high conductivity and hierarchical microspheres with strong interface interaction, the a-V2O5@CNTs exhibited abundant active sites, fast reaction kinetics as well as eminent structure stability. As a promising electrode material, the a-V2O5@CNTs displayed high specific capacity (480 mAh g-1 at 0.5 A g-1), good rate capability and long-term stability under high current density (158 mAh g-1 at 30 A g-1 over 1000 cycles). Meanwhile, the corresponding mechanism was further illustrated through different characterizations. Furthermore, the as-assembled flexible pouch battery based on the a-V2O5@CNTs delivered outstanding flexibility and feasibility. Hence, this work provides a new idea for developing high performance cathode materials of aqueous zinc-ion batteries.