Layered (NH₄)_1.32Na_0.95V₆O₁₆·1.88H₂O Nanobelt as a High Performance Cathode Material for Aqueous Zinc-Ion Batteries

Rechargeable aqueous zinc-ion batteries (AZIBs) have attracted increasing attention owing to their high theoretic capacity and safe nonflammable electrolytes. Vanadium-based cathode materials have emerged as promising candidates for AZIBs owing to their multivalent redox chemistry and expanded interlayer architectures for high specific capacity. In this work, (NH 4 ) 1.32 Na 0.95 V 6 O 16 ·1.88H 2 O (NNVO) is developed as a high performance cathode material for AZIBs. In this work, Na + not only serves as a pillar to increase the interlayer spacing but also acts as a guest sacrificial template for intercalated Zn 2+ ions. The residue Na + still works as a pillar to support the vanadium layers, and the replaced Na + by Zn 2+ works as a guest sacrificial template to make it easier for the host accommodating Zn 2+, thereby stabilizing the interlayer spacing. As a result, The NNVO cathode exhibits a good rate capability, achieving a capacity of 460.2 mAh g –1 at 0.1 A g –1 and 195 mAh g –1 at 5 A g –1, a good stability with 89.6% retention after 3500 cycles at 5 A g –1 . This work provides a reference for engineering cathode materials in aqueous batteries.