Recent advances in vanadium-based materials for aqueous metal ion batteries: Design of morphology and crystal structure, evolution of mechanisms and electrochemical performance

Abstract

Aqueous metal ion batteries have attracted increased attention as possible alternative to lithium ion batteries for large-scale electrical energy storage applications due to the environmental friendliness, intrinsic safety, and low cost of the aqueous electrolytes. Thus, a lot of research efforts have been devoted to searching for various electrode materials for the insertion/extraction of metal ions. Recently, owing to high theoretical capacity and abundant embedded sites, vanadium(V)-based materials have attracted more and more attention. However, the inadequacies of V-based materials in the aqueous electrolytes also hindered its fast development and commercialization process. In this review, the intercalation mechanisms of metal ions are introduced, and structural optimizations are highlighted, such as morphology designs, the introduction of oxygen vacancies, and regulation of lattice structures, aiming to increase the intercalation space and structural stability of V-based materials. Moreover, the recent evolution of the electrochemical performances of V-based materials in different aqueous metal ion batteries systems, including alkali-metal ions, Zn2+ ions, and other multivalent ions are comprehensively covered and evaluated. Based on current advances, the researching directions and challenges associated with V-based materials in aqueous metal ion batteries, and the future perspectives of aqueous metal ion batteries used vanadium-based materials as electrodes are concluded in the end. Finally, this review will pave the way to the design of aqueous metal ion batteries with good reversibility and long cycle life in the future.