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

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.