Smart symbiotic lithium-sulfur batteries under extremely low-temperature conditions

Abstract Lithium-sulfur batteries (LSBs) fail catastrophically under ultra-low temperature due to frozen polysulfide conversion kinetics, with no existing technology achieving high-energy-density operation below −40°C. Here, we report a self-regulating LSB system, the “smart symbiosis” cell, that activates multi-field synergy (MFSN) at interface reaction sites to overcome kinetic barriers under low temperature. This directly modulates the transport of ions/electrons and the spin electron states of reaction sites at the quantum level, enabling wave-shaped charge/discharge profiles and achieving a ratio of 3.11 between the first plateau and the second plateau (theoretical value 3.0). The ultra-theoretical capacity mechanism is revealed—magnetic field-induced enhancement of kinetics and interfacial reactions. The pouch cell achieves an energy density of 454.5 Wh kg–1 (based on total system mass) and 219.1 Wh kg–1 (with device consumption) at −80°C. This technology could increase the capacity of batteries by 9.5 times at low temperatures with an energy consumption of ∼0.091%°C–1 of the battery energy, while the conversion retention rate remains as high as 87% after 200 cycles (∼2800 hours), and breaks the lowest temperature record. This new battery system opens the door to extremely wide temperature applications for LSBs, and could be extended to other batteries.