X. Wang, Y.G. Li, S. Wang, F. Zhou, P. Das, C.L. Sun, S.H. Zheng, and Z-S Wu*

Advanced Energy Materials, 2020, 10, 2000081.

DOI: 10.1002/aenm.202000081 [PDF]

This work has been highlighted by MaterialsViewsChina

Rechargeable aqueous zinc-ion batteries (ZIBs) are swiftly appealing due to high safety, zinc abundance, and low cost. However, developing qualified cathode materials remains a great challenge. Herein, a novel two-dimensional (2D) heterostructure of ultrathin amorphous vanadium pentoxide (A-V₂O₅) uniformly grown on graphene (A-V₂O₅/G) with very short ion diffusion pathway, abundant active sites, high electrical conductivity, and exceptional structural stability, is demonstrated for highly reversible aqueous ZIBs (A-V₂O₅/G-ZIBs), coupling with unprecedented high capacity, rate capability, long-term cyclablity and excellent safety. As a result, 2D A-V₂O₅/G heterostructures for stacked ZIBs at 0.1 A/g display ultrahigh capacity of 489 mAh/g, outperforming all reported ZIBs, with admirable rate capability of 123 mAh/g even at 70 A/g. Furthermore, the new-concept prototype planar miniaturized zinc ion microbatteries (A-V₂O₅/G-ZIMBs) present high volumetric capacity of 20 mAh/cm³at 1 mA/cm², long cyclability holding high capacity retention of 80% after 3500 cycles and in-series integration, demonstrative of great potential for high-safe microsized power sources. Therefore, the exploration of such 2D heterostructure materials with strong synergy is a reliable strategy for developing safe and high-performance energy storage devices.