V6O13-delta@C Nanoscrolls with Expanded Distances between Adjacent Shells as a High-Performance Cathode for Knittable Zn-ion Battery.

Herein, the defective vanadate oxide (V 6 O 13-delta )/C (denoted as DVOC) nanoscrolls with large distance between adjacent shells are constructed as a cathode material for ZIBs. By simultaneously enlarging the distance between adjacent shells and engineering the defective structure for oxide crystal, the DVOC nanoscrolls achieve fast kinetics, high reversibility and good energy storage capability. The formation process of DVOC nanoscrolls is investigated and a self-assembling-rolling sequential mechanism is disclosed. Moreover, the fiber-shaped flexible ZIBs are fabricated based on the DVOC cathode. Their admirable volumetric energy density, good high rate capability and excellent cycling stability demonstrate the superiority of the unique structure. Therefore, this work not only introduces a novel strategy to improve the properties of the vanadium oxides, but also provides a new clue to the design of knittable power sources for flexible electronics.