Multiscale porous structured MXene: Synthesis, design and applications in batteries and supercapacitors

The porous structure of 2D MXene play a critical role in addressing ion transport and kinetic limitations of traditional electrodes, enabling significant improvements of electrochemical performance for energy storage applications. In contrast to previous reviews those have focused only on a specific type of pore structure, this review systematically summarizes the construction strategies and structural properties of micropores, mesopores, and macropores of MXene electrodes, and outlines their evolution from single-scale regulation to multiscale synergistic coupling enhancement. On the basis of a brief review of the synthesis methods and physicochemical properties of MXene, we detail the introduced key structural parameters (e.g. pore size, pore geometry), and elucidate their synergistic effect on ion/electron transport pathways, active site exposure, and electrolyte wettability. Furthermore, this review analyzes the unique roles and synergies of different pore scales in energy storage mechanisms, and discusses the application progress of multiscale porous MXene in lithium-ion batteries, zinc-ion batteries, supercapacitors, and so on. This review aims to provide practical insights into the rational design and application of multiscale porous MXene, thereby promoting advancements in energy storage technologies and related fields.