Self-supported carbon cloth based-ammonium vanadate nanoribbons cathode for superior flexible aqueous zinc-ion batteries

Ammonium vanadate (NH4V4O10) is a prominent cathode material for zinc ion storage owing to the abundant active sites, tunable layered structure, and the multivalence state of vanadium ions. Despite the great potential of NH4V4O10, it is constrained by its weak fastness and homogeneity with substrates. A key issue with poor energy storage of flexible battery is extremely low active material load quality. Additionally, the severe self-aggregation phenomena and the brittle interlayer structures are the cause of the rapid capacity fading and the poor rate capacities. Herein, a novel flexible self-support carbon cloth (CC)-based NH4V4O10 (CC@NH4V4O10) cathode was rationally fabricated via a simple hydrothermal method. Apart from serving as a flexible interconnected conductive network, CC can provide uniform nucleation centers and induces ordered growth of NH4V4O10, which effectively reduces its agglomeration problem. The synthesized NH4V4O10 nanoribbons exhibit a unique micropore structure with enlarged interlayer spacing, which ensures rapid co-transfer of H+/Zn2+ ions with enhanced storage capacity. The CC@NH4V4O10 cathode delivers a stable specific capacity of 330 mAh g−1 at 0.25 A g−1 with almost no capacity fading (99% capacity retention) over 600 cycles at 5 A g−1. More impressively, the as-prepared package battery offers outstanding operation stability to power electronics under the low temperature, and it is able to maintain 76% energy retention after 100 cycles at 0 ℃ at a 0.5 A g−1 current density. This high-performance flexible battery may open a new prospect in wearable energy storage applications.