Electrolyte-Impregnated Mesoporous Hollow Microreactor to Supplement an Inner Reaction Pathway for Boosting the Cyclability of Li-CO Batteries.

Li-CO batteries that integrate energy storage with greenhouse gas fixation have received a great deal of attention in the pursuit of carbon neutrality. However, cyclic accumulation of the insulative and insoluble LiCO on the cathode surface severely restrains the battery cyclability, especially under a high depth of discharge/charge. Herein, we design and fabricate a microreactor-type catalyst by embedding Ru nanoparticles into the shells of mesoporous hollow carbon spheres. We show that both the hollow cavity and mesoporous shell are indispensable for concertedly furnishing a high activity to catalyze reversible LiCO formation/decomposition. This unique structure ensures that the Ru sites masked by exterior LiCO deposits during charging can resume the redox process of discharge by working with the prestored electrolyte to establish an inner reaction path. The thus fabricated Li-CO batteries demonstrate remarkable cyclability of 1085 cycles under 0.5 Ah g and 326 cycles under 2 Ah g at 1 A g, outshining most of the literature reports. This study highlights a smart catalyst design to boost the reversibility and cyclability of Li-CO batteries through an "in & out" strategy.