Capture and reduction of singlet oxygen via an anthracene-based framework for stable Li-O ₂ batteries

Given the increasing global energy demand and rapid advancement of low-carbon technologies, Li-O ₂ batteries have attracted considerable attention owing to their exceptionally high theoretical energy density, offering great promise for advanced energy systems. However, the formation of harmful singlet oxygen ( ¹ O ₂ ) in both discharge and charge processes induces parasitic reactions that deteriorate round-trip efficiency and cycling stability. Herein, an anthracene-based covalent-organic framework (AntCOF) is introduced as a highly effective catalyst for the ¹ O ₂ reduction reaction (SORR) in Li-O ₂ batteries. The conjugated porous framework selectively captures electrophilic ¹ O ₂ , enabling effective charge transfer from AntCOF to the empty π* orbital of ¹ O ₂ and promoting SORR in subsequent discharge processes. This mechanism suppresses ¹ O ₂ diffusion and mitigates associated side reactions, leading to reduced overpotentials and improved cycling performance when coupled with a RuO ₂ catalyst. This work may enlighten further investigations into ¹ O ₂ -related chemistry across a broad range of oxygen-redox electrochemical systems.