Unlocking the Orbital Interaction Mode in Li-O2 Batteries.

Understanding electrocatalyst-intermediate orbital interaction in oxygen evolution reactions (OER) is critical for designing high-performance lithium-oxygen (Li-O2) batteries, yet remains a significant challenge. In this study, we employed a CdSe-based catalyst as a model cathode to deeply investigate the catalyst-intermediate interaction and its effect on OER activity. Compared to the 4d orbital electronic states of Cd in CdSe, electron transfer from CdSe to ZnS in the CdSe/ZnS heterojunction results in a downward shift of the Cd 4d suborbital energy levels. The differences in the Cd 4d orbital electronic states between CdSe and CdSe/ZnS cause distinct orbital interaction mode with LiO2 intermediate, ultimately leading to variations in OER activity. Specifically, compared to the strong Cd 4dxy-O 2Px/y orbital interaction mode between CdSe and LiO2, the weaker Cd 4dz 2-O 2Py orbital interaction mode between CdSe/ZnS and LiO2 significantly reduces the activation energy of the rate-determining step, thereby enhancing OER activity. This finding provides theoretical guidance for the design of OER electrocatalysts in Li-O2 batteries.