Boosting the Cyclic Stability of Aqueous Zinc-Ion Battery Based on Al-Doped V₁₀O₂₄·12H₂O Cathode Materials

Rechargeable aqueous zinc-ion batteries (ZIBs) are considered an alternative energy storage system to lithium-ion battery because of its low price and high safety. However, the development of zinc-ion battery is limited by positive materials, which usually show poor cycling life because of the strong electrostatic interaction between divalent Zn²⁺ ions and crystal structure of materials. Developing a cathode material with a stable structure upon cycling is still a big challenge for researchers worldwide. Doping foreign elements, which can solidify the lattice, is an effective approach to improve the structural stability of materials. However, hardly any research based on the doping method for aqueous ZIBs has been reported. Here, we develop an Al-doped layer material of V₁₀O₂₄·12H₂O as cathode material for aqueous ZIBs. Benefitting from the stable layered structure, the material exhibited an excellent cycling life with 98% capacity retention after 3000 cycles, which is much higher than the 65% in the pure V₁₀O₂₄·12H₂O. The great enhancement on the cycle performance indicates that Al-doping can help build an advanced zinc-storage system.