Insights into the impact of interlayer spacing on MXene-based electrodes for supercapacitors: A review

The preponderance in structural and electrochemical properties enable two-dimensional (2D) MXene occupy an important position in energy storage industrial, especially in supercapacitor system. MXene has been praised as a promising class of 2D metal carbide, nitride, and carbon-nitride. The good electrical conductivity, abundant surface functional groups, tunable hydrophilic/hydrophobic nature, and copious redox active reaction sites endow MXene with excellent charge storage capacity. In this paper, the synthesis of MXene and the development of its energy storage performance in recent years are reviewed. In particular, we emphatically focus on the impact of interlayer distance regulation on the electrochemical properties of MXene when it was used as supercapacitor electrodes. Finally, from the optimization of MXene interlayer state to the revelation of energy storage mechanism, the current limitations and improvement directions are further proposed. This paper hopes to provide positive guidance for the practical industrial application of MXene-based electrodes in the future.