Chirality-Induced Suppression of Singlet Oxygen in Lithium-Oxygen Batteries with Extended Cycle Life.

Lithium-oxygen (Li-O) batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage, utilizing ambient air as an energy source, eliminating the need for costly cathode materials, and offering the highest theoretical energy density (~ 3.5 kWh kg) among discussed candidates. Contributing to the poor cycle life of currently reported Li-O cells is singlet oxygen (O) formation, inducing parasitic reactions, degrading key components, and severely deteriorating cell performance. Here, we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets (CoO NSs) as cathode materials to suppress O in Li-O batteries for the first time. Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in O during discharge and charge, respectively, compared to conventional carbon paper-based cells, consistent with differential electrochemical mass spectrometry results, which indicate a near-theoretical charge-to-O ratio (2.04 e/O). Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level, enhancing Co 3d-O 2p hybridization, stabilizing reaction intermediates, and lowering activation barriers for LiO formation and decomposition. These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O batteries, abridging the current gap to commercialization.