Novel design strategies of three-dimensional MXene structures and their applications in metal-ion hybrid capacitors

MXene is a novel two-dimensional material that exhibits excellent competitive performance in energy storage and conversion applications due to its high electrical conductivity, good dispersibility, and abundant surface functional groups. However, the van der Waals interactions between MXene nanosheets tend to lead to stacking, which limits the number of active sites and ion dynamics. Constructing MXene materials into three-dimensional (3D) porous structures is an effective strategy to improve energy storage performance by increasing specific surface area and porosity, and decreasing ion transport distance. This review provides an overview of four novel design strategies for preparing three-dimensional MXene materials, including template-based, 3D printing, electrospinning, and gas-assisted methods, over the last 5 years (2019–2023), and explores the potential applications of 3D MXene structures in the new-type energy storage systems of metal-ion hybrid capacitors. Finally, the authors provide prospects for the future development of 3D MXene structures.