Ultrathin Ti 3 C 2 T x nanosheets modified separators for lithium–sulphur batteries

Abstract Currently, among the various emerging energy storage systems, the lithium–sulphur (Li‐S) battery is expected to be one of the next‐generation lithium secondary batteries with high efficiency. However, the practical application of Li‐S batteries still faces many obstacles. To solve the shuttle effect of lithium polysulphides, ultrathin Ti 3 C 2 T x nanosheets were prepared through the in‐situ acid etching method and applied to separator modification to suppress the shuttle effect of lithium polysulphides. Ultrathin Ti 3 C 2 T x nanosheets with enlarged interlayer spacing accelerated the migration of Li + . The abundant termination groups on the surface of Ti 3 C 2 T x played the role of the lithium polysulphide capture centre. When the mass loading of separator modification materials was set as 0.025 mg cm −2 , the as‐prepared battery exhibited a reversible specific capacity as high as 780 mAh g −1 after 200 cycles at 0.2 C, and the single‐cycle capacity decay rate was only 0.09%.