Facile Self‐Assembly of Coral‐Like MXene‐Sulfur Free‐Standing Electrodes for Efficient Polysulfide Confinement and Accelerated Redox Kinetics

ABSTRACT Lithium–sulfur (Li–S) batteries are promising for high‐energy‐density applications but face challenges such as polysulfide shuttling and sluggish sulfur redox kinetics. In this study, we propose a facile low‐cost hydrogen chloride–assisted gelation strategy to fabricate a free‐standing, coral‐like MXene/carbon nanotube (CNT) foam cathode at ambient temperature and pressure. This self‐assembly process eliminates the need for high‐temperature or high‐pressure conditions, making it suitable for large‐scale production. The hierarchical porous structure provides multiscale confinement and continuous ion/electron pathways, enhancing both polysulfide confinement and ion transport. The chloride‐induced surface modification of MXene promotes a transition from 2D film‐like to 3D particulate sulfur deposition, improving redox kinetics and mitigating electrode passivation. The resulting cathode delivers excellent electrochemical performance, achieving 775 mAh g ⁻¹ at 4 C with 74.5% retention after 500 cycles and maintaining 827 mAh g ⁻¹ at 0.5 C under practical conditions (high sulfur loading, lean electrolyte), with a low decay rate of 0.11% per cycle. This work demonstrates the potential of self‐assembly and surface chemistry modulation in enhancing Li–S battery performance without the need for complex or energy‐intensive synthesis.