Interlayer-Expanded V₆O₁₃·nH₂O Architecture Constructed for an Advanced Rechargeable Aqueous Zinc-Ion Battery

Rechargeable aqueous zinc-ion batteries have been intensively studied as novel promising large-scale energy storage systems recently, owing to their advantages of high abundance, cost effectiveness, and high safety. However, the development of suitable cathode materials with superior performance is severely hampered by the sluggish kinetics of Zn2+ with divalent charge in the host structure. In the present work, a highly reversible aqueous Zn2+ battery is demonstrated in aqueous electrolyte using V6O13·nH2O hollow microflowers composed of ultrathin nanosheets. Benefiting from the synthetic merits of its favorable architecture and expanded interlamellar spacing that results from its structural water, the V6O13·nH2O cathode exhibits outstanding electrochemical performances with a high reversible capacity of 395 mAh g–1 at 0.1 A g–1, superior rate capability, and durable cycling stability with a capacity retention of 87% up to 1000 cycles. In addition, the reaction mechanism is significantly investigated in detail. This study demonstrates that the V6O13·nH2O nanostructure is emerging as a promising cathode material for the high-potential rechargeable aqueous zinc-ion battery, and it may shed light on the water-initiated effective interlayer engineering strategy for the construction of high-performance cathode materials for grid-scale energy storage devices.