Enhanced catalytic conversion of polysulfide using 1D CoTe and 2D MXene for heat-resistant and lean-electrolyte Li–S batteries

The key to achieving high-power, high-energy, and high-level safety for Li–S batteries is to accelerate the polysulfide conversion via electrocatalysis. Herein, we develop a bifunctional electrocatalytic 1D-2D CoTe-MXene separator modifier for heat-resistant and lean-electrolyte Li − S batteries. This combination of multiple compositions and hierarchical architecture design improves the separator's thermal durability while also speeding up Li₂S nucleation and decomposition. As a result, Li − S batteries with CoTe-MXene separators achieve the high discharge capacity of 1664 mAh g⁻¹, excellent rate capability (905 mAh g⁻¹ at 3C), and long-term cyclability at 60 °C. More impressively, the battery can deliver a high areal capacity of 9.0 mAh cm⁻² even at a lean electrolyte (3 µL mg⁻¹) and a high temperature (60 °C), which is rarely achieved by traditional Li–S batteries.