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.
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