Photo-Energized MoS2/CNT Cathode for High-Performance Li–CO2 Batteries in a Wide-Temperature Range

Li-CO₂ batteries are considered promising energy storage systems in extreme environments such as Mars; however, severe performance degradation will occur at a subzero temperature owning to the sluggish reaction kinetics. Herein, a photo-energized strategy adopting sustainable solar energy in wide working temperature range Li-CO₂ battery was achieved with a binder-free MoS₂/carbon nanotube (CNT) photo-electrode as cathode. The unique layered structure and excellent photoelectric properties of MoS₂ facilitate the abundant generation and rapid transfer of photo-excited carriers, which accelerate the CO₂ reduction and Li₂CO₃ decomposition upon illumination. The illuminated battery at room temperature exhibited high discharge voltage of 2.95 V and mitigated charge voltage of 3.27 V, attaining superior energy efficiency of 90.2% and excellent cycling stability of over 120 cycles. Even at an extremely low temperature of - 30 °C, the battery with same electrolyte can still deliver a small polarization of 0.45 V by the photoelectric and photothermal synergistic mechanism of MoS₂/CNT cathode. This work demonstrates the promising potential of the photo-energized wide working temperature range Li-CO₂ battery in addressing the obstacle of charge overpotential and energy efficiency.