NH3 modified β-Na0.33V2O5 with high capacity for aqueous zinc ion battery cathode

Vanadium-based materials with high capacity and stability are needed to promote aqueous zinc ion batteries in large-scale energy storage. NH3 modified beta-Na0.33V2O5 is prepared by a facile hydrothermal method and subsequent calcination. The NH3 modification mechanism of beta-Na0.33V2O5 is proposed, which includes forming vacancies, structural defects and V-O-N bonds after escaping most ammonia molecules from beta-Na0.33V2O5's framework, and retaining a small part of ammonia molecules in its structure. In the Zn/beta-Na0.33V2O5 battery system, the beta-Na0.33V2O5 delivers a high capacity of 430 mAh g(-1) at 200 mA g(-1) and good structural stability. After 50th cycles at 200 mA g(-1), the beta-Na0.33V2O5 modified by NH3 under N-2 atmosphere possesses a lower Warburg coefficient of 19.90 Omega cm(2)s(-0.5) than 29.3 Omega cm(2)s-(0.5) of beta-Na0.33V2O5 without modification. The rigid beta-Na0.33V2O5 is opened by small NH3 molecules, which provides new horizons for optimizing tunneled vanadium-based materials for aqueous zinc ion batteries. (C) 2021 Elsevier B.V. All rights reserved.