Ultrathin RuRh Alloy Nanosheets Enable High-Performance Lithium-CO₂ Battery

Ultrathin triangular RuRh alloy nanosheets have been successfully synthesized, and demonstrated as an exceptionally active catalyst for significantly activating CO₂ reduction and evolution reactions, which endow the Li-CO₂ battery with superior cycling performance and rate capability. At 1,000 mA g⁻¹, the Li-CO₂ battery with RuRh catalysts can stably discharge and charge up to 180 cycles without capacity decay, and the voltage gap of terminal discharge and charge potentials is only 1.35 V and still below 1.60 V at the 180^th cycle, which is the best rate capability reported to date. Alloying Ru with Rh can impose a high activity in electron transfer of surface Ru, thus not only favoring CO₂ reduction and Li₂CO₃ nucleation but also facilitating Li₂CO₃ decomposition. In such a scenario, the Li-CO₂ battery composed of ultrathin RuRh alloy nanosheets provides a promising strategy to concurrently achieve highly renewable energy-storage devices and greenhouse gas utilization.