Large Lattice-Spacing (NH4)2V10O25 as Flexible and Stable Quasi-Solid-State Zinc Ion Battery

Flexible quasi-solid-state batteries have flourished with the increasing demand for wearable and portable electrical devices. In particular, aqueous zinc ion batteries (ZIBs) stand out as promising candidates for flexible energy storage systems owing to their minimal toxicity, environmental friendliness, and cost-effectiveness. Nevertheless, the lack of effective cathode materials still hinders their widespread usage. Herein, large lattice-spacing (NH4)2V10O25·8H2O combined with reduced graphene oxide (rGO), denoted as NHG, is harvested. The NHG composite demonstrates the ameliorated zinc storage and long-term durability, such as a notable specific capacity of 407.5 mAh g–1 at 0.2 A g–1 and a long-lasting reversibility of 230.7 mAh g–1 after 3000 cycles at 5.0 A g–1. Furthermore, flexible quasi-solid-state batteries also afford a superior capacity retention of 81% over 640 cycles. These findings suggest that NHG has a promising potential as a ZIB cathode and enhances the wide variety of practical applications of vanadium-based materials as flexible quasi-solid-state zinc ion batteries with stability.