MXenes as an emerging class of two-dimensional materials for advanced energy storage devices

A class of two-dimensional (2D) transition metal nitrides and carbides (MXenes) has emerged as a promising paradigm. Their unique architecture such as controllable interfacial chemistry, high electronic conductivity, tunable layered structures, etc., has drawn a great amount of attention. This makes the MXene family a promising class of materials in a variety of applications, including energy storage, electrocatalysis, medicine, water purification etc. However, the practical applicability of MXenes in energy storage systems is relentlessly limited by the issues of poor material utilization efficiency, slow reaction kinetics and limited active sites. Herein, the most recent achievements in rational microstructural design and synthesis for improving the energy storage performance of MXene-based materials have comprehensively been summarized. The present review describes the synthesis and characteristics of MXenes followed by their structural features and applications in energy storage devices. Then the focus turned towards the state-of-the-art progress of MXene-based materials for metal-sulfur batteries, alkali metal-ion batteries, and zinc ion batteries (ZIBs). Finally, the opportunities and critical challenges for future 2D MXene-based nanoarchitecture research are discussed, with the aim of providing a comprehensive reference for the engineering of MXene-based electrodes for electrochemical energy storage.