3D MXene architectures as sulfur hosts for high-performance lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are one of the most promising energy storage devices because of their high theoretical energy density; however, inherent issues including poor electrical conductivity and severe dissolution of S and its discharged products hinder their practical applications. MXenes have metallic conductivity, ultra-thin two-dimensional (2D) structures, rich surface functional groups, and macrostructural adjustability and have been widely used to design advanced sulfur hosts. 3D network structures assembled by 2D MXene nanosheets have shown superior performance for improving reaction kinetics, accommodating and dispersing sulfur at the micro-/nanoscale, and capturing polysulfides due to their porous interconnected structure. Herein, the applications of MXene architectures related to 2D layered structures, 3D multilayered structures, and 3D spherical structures as sulfur hosts are reviewed. The structure-performance relationship, challenges for current designs, and opportunities for future 3D architectures for LSBs are also analyzed.