Light-induced alternating catalysis on single-atom ruthenium embedded in covalent organic frameworks for high-performance photo-assisted li–o2 batteries

Abstract

The development of high‐efficiency cathode catalysts is crucial for advancing photo‐assisted non‐aqueous lithium–oxygen (Li–O 2 ) batteries, which leverage solar energy to reduce the high overpotential for driving oxygen reduction and evolution processes. However, the state‐of‐the‐art photo‐cathode catalysts often lack multi‐step conversion pathways that regulate interactions between complex active sites and reactive oxygen‐related intermediates within Li–O 2 battery systems. Herein, we report a new light‐induced alternating catalytic mechanism based on a single‐atom Ru‐embedded covalent organic framework assembled from a triazine‐core C3‐symmetric node and π‐extended perylene‐diimide linkers (T‐PDI), generating an ordered conjugated Ru/T‐PDI network that functions as a high‐performance photo cathode of the Li–O 2 battery. Unlike conventional photo‐assisted catalysts that operate through the single‐site activity, the Ru/T‐PDI electrode enables dynamic migration and efficient conversion of reactive oxygen species between catalytic sites across multiple selective sites. This mechanism orchestrates the multi‐step transformation process within Li–O 2 batteries, significantly enhancing catalytic efficiency of active sites and facilitating both the formation and decomposition of Li 2 O 2 products. As a result, the photo‐assisted Li–O 2 battery employing the Ru/T‐PDI cathode achieves a quite low overpotential, outstanding cycling stability and excellent rate performance. This work provides crucial insights for reaction mechanism studies and catalyst design for next‐generation light‐driven metal–oxygen batteries.