Entropy‐Modulated Short‐Chain Cathode for Low‐Temperature All‐Solid‐State Li−S Batteries

Abstract All‐solid‐state Li−S batteries (ASSLSBs) due to high theoretical energy density and exceptional safety are highly desirable for electric aircraft. However, as the flight altitude rises, the low‐temperature performance is hampered by inadequate practical capacity. Here, we discover that low‐temperature sulfur utilization is constrained by the multi‐step endothermic conversion reaction. By introducing multi‐chalcogen to modulate the local entropy, a short‐chain molecule cathode is designed to shorten the reduction pathways and enhance low‐temperature discharge capacity. Furthermore, the mismatched lithiation lattice of the short‐chain cathode reduces the decomposition energy barriers, thus enhancing low‐temperature charge/discharge reversibility. The designed short‐chain cathode exhibits high cathode utilization (99.4 %) and cycling stability (400 cycles, 92.2 % retention) at room temperature, as well as delivers excellent discharge capacity (579.6 mAh g −1 , −40 °C) and cycling performance (100 cycles, 98.4 % retention, 394.9 Wh kg − 1electrode, −20 °C) at low temperature. This study presents new opportunities to stimulate the development of low‐temperature ASSLSBs.