Scalable Metal Free Zinc Ion Capattery Enabled by Interstitial Defect Engineering of Nanoscale n-Type Zinc Vanadate

Abstract

This Letter explores the energy storage properties of nano zinc vanadate in zinc metal batteries and a Zn metal free capattery. The synthesis is a simple scalable solution state mechanochemical route with uniform nanosized one-dimensional zinc vanadate. The synthesized vanadate is engineered using NMP at the electrode fabrication stage to position the Zn 2+ ions at an easily extractable site. This in turn tunes the bandgap from 2.38 to 2.16 eV, creating oxygen defective vacancies in the crystal lattice. In addition, electrochemical analysis of the engineered cathode is studied in a half-cell device that is further developed into a zinc metal free zinc ion capattery (ZiC). The developed metal free capattery delivered a capacity of 120 mAh g −1 at a current density of 100 mA g −1 , and a pouch cell is fabricated to power lightemitting diodes.