High-Capacity and Long-Cycle Lifetime Li−CO₂/O₂ Battery Based on Dandelion-like NiCo₂O₄ Hollow Microspheres

As a promising energy storage technology, Li−CO₂/O₂ battery with ultrahigh discharge capacities have received much attention, reaching capacities three times that of Li−O₂ batteries. Herein, using an excellent catalyst, NiCo₂O₄ designed as a 3D dandelion-like hollow nanostructure, a Li−CO₂/O₂ battery is systematically investigated to understand how the reaction mechanisms are affected by CO₂. With CO₂ stabilization, the batteries could achieve a specific discharge capacity as high as 22000 mAh/g and a long-term cycling performance of up to 140 cycles without apparent deterioration. In addition, the intrinsic mechanism of the current density influence is explored based on the Li₂CO₃ morphology evolution. Superoxide anion radical species (O₂^.−) were identified to be rapidly consumed by CO₂, which dramatically enhances the stability of Li−O₂ batteries. The results indicate that the NiCo₂O₄ nanocatalyst can efficiently inhibit Li₂CO₃ aggregation and realize the maximum utilization of active sites. The results confirm that the 3D dandelion-like NiCo₂O₄ catalyst can be a potential cathode for Li−CO₂/O₂ batteries.