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

Area of Science:

• Electrochemistry
• Materials Science
• Quantum Mechanics

Background:

• Lithium-sulfur batteries (LSBs) exhibit catastrophic failure below -40°C due to frozen polysulfide conversion kinetics.
• Existing technologies fail to achieve high-energy-density operation in ultralow temperatures.

Purpose of the Study:

• To develop a self-regulating LSB system capable of operating at ultralow temperatures.
• To overcome kinetic barriers and enhance ion/electron transport and spin states at reaction sites.

Main Methods:

• Development of a 'smart symbiosis' cell with multifield synergy at interface reaction sites.
• Modulation of ion/electron transport and spin electron states at the quantum level.
• Investigation of magnetic field-induced enhancement of kinetics and interfacial reactions.

Main Results:

• Achieved wave-shaped charge/discharge profiles with a plateau ratio of 3.11 (theoretical 3.0).
• Demonstrated a pouch cell energy density of 454.5 Wh kg⁻¹ (system mass) and 219.1 Wh kg⁻¹ (device consumption) at -80°C.
• Reported a 9.5x capacity increase at low temperatures with 87% retention after 200 cycles.

Conclusions:

• The 'smart symbiosis' cell overcomes kinetic barriers, enabling LSB operation at -80°C.
• Magnetic field-induced enhancement is key to the ultratheoretical capacity mechanism.
• This technology enables extremely wide temperature applications for LSBs and potentially other battery types.