Regulating the Local Spin States in Spinel Oxides to Promote the Activity of Li‐CO 2 Batteries

Abstract Due to the high energy barrier, slow reaction kinetics, and complex reaction environments of Li‐CO 2 batteries, the development of durable and efficient catalysts is essential. Transition metal oxides are promising for their availability, stability, and 3d electronic features, with spin states playing an important role in CO 2 activation. In this study, the local spin states are regulated by incorporating Ni into Co 3 O 4 and its impact on activity in Li‐CO 2 batteries is explored. The results show that Ni atoms with high spin states in Ni 0.1 Co 2.9 O 4 facilitate electron transfer from the catalyst to the unoccupied orbitals of CO 2 , providing sufficient active sites for the nucleation and growth of small Li 2 CO 3 crystals. These small crystals have a low decomposition barrier, leading to improved battery efficiency. Therefore, Ni 0.1 Co 2.9 O 4 shows superior catalytic performance with an overpotential of 0.72 V and an energy efficiency of ≈70% after 500 h. This work provides insights into the relationship between spin states and CO 2 reactions, highlighting a promising avenue for developing high‐performance metal‐CO 2 batteries.