High entropy MXenes in energy storage: structural design, characterization, and applications

Abstract

High-entropy MXenes have rapidly become a highly sought-after research topic due to their unique two-dimensional layered structures and outstanding electrochemical performances. Although high-entropy MXenes have achieved significant breakthroughs in the energy storage fields, there exist substantial challenges to them, like the multi-element uncertainty and high-entropy complexity. Therefore, it is of great importance to explore the high-entropy structure, high-entropy composition, and high-entropy properties of MXenes. In this review, we explore the fundamental principles of high-entropy MXenes in energy storage systems, providing a profound discussion of high-entropy MXenes' synthesizing methods, crystal structures, and characterization techniques. Furthermore, we comprehensively analyse their electrochemical performance, while systematically reviewing their design and optimization strategies. These strategies include element manipulation, crystal structure engineering, composite integration and surface modification. In addition, this review also outlines the applications and future prospects of high-entropy MXenes in energy storage and other potential fields. Finally, this review endeavors to provide possibilities aimed at guiding the design and optimization of high-entropy MXenes, thereby promoting their application in energy storage.