Review of MXenes and their composites for energy storage applications

MXenes have captured the interest of scientists and technologists in several domains, especially devices for storing energy like supercapacitors (SC) as well as flexible batteries. Because of their distinctive optical, mechanical, electrochemical, electrical, and physicochemical capabilities, pure MXene and their hybrids are increasingly being used in several kinds of energy storage devices. Some recently used MXene and MXene hybrid materials have shown attractive energy parameter values like energy density, specific capacity, gravimetric capacity, volumetric capacity, and power density as well. Regarding high electrochemical performances (MWCNT)/V2CTx, hybrid material plays a vital role, giving the highest capacitance value of 1872 Fg−1 compared to other composite materials. The electrodes fabricated using (MWCNT)/V2CTx demonstrated a retention capacity of 94 % during a 10,000-cycle lifespan and gave satisfactory rate performance. The addition of MWCNTs improved the reaction kinetics and conductivity of the MXenes while facilitating the ability to store charges, which is advantageous for future smart devices for storing energy. In addition to providing a thorough discussion of the electrochemical energy storage applications, such as batteries (like; Lithium, sulphur, potassium and metal sulphur batteries) and supercapacitor. This review concentrates on the MXene and MXene hybrid materials synthesis techniques, properties and summarises recent advancements in Storage applications. The intricate design of MXenes' Nano-microstructures is given special consideration in light of their many functions as electrodes, multifunctional parts, or protective layers for metal anodes. The article concludes with the possible avenues for future MXene material synthesis, structure, characteristics, analysis, and production research. Various problems that occur during the synthesis of MXene and its composite materials are discussed in detail.