Polymorphs of VO2 and their MXene-based hybrid materials for energy storage applications

Abstract

VO2 polymorphs have gained attention as promising energy-storage materials because of their well-defined crystal structures. However, their practical use as electrode material is hindered by poor electrical conductivity and volume instability. To overcome these limitations, VO2 has been integrated with MXene to form VO2@MXene hybrids. MXene high surface area, electrostatic attraction, and chemical bonding make it ideal partner for VO2. These VO2@MXene hybrids address the intrinsic drawbacks of VO2, enhancing its electrochemical performance. Furthermore, VO2@MXene hybrids utilized for energy storage applications, mainly for supercapacitors and batteries. This review article thoroughly explores the recent advancements in the synthesis of VO2 polymorphs and VO2@MXene hybrids, their implementation as the electrode material under various electrolytic reaction conditions, and the optimized electrochemical parameters that led to superior electrochemical performances. Additionally, it discusses the interaction and charge storage mechanism between the VO2 and MXene in the hybrid structure studied in various electrolytes.