A Supramolecular Deep Eutectic Electrolyte Enhancing Interfacial Stability and Solution Phase Discharge in Li−O2 Batteries

Li−O2 batteries (LOBs) have gained widespread recognition for their exceptional energy densities. However, a major challenge faced by LOBs is the lack of appropriate electrolytes that can effectively balance reactant transport, interfacial compatibility, and non‐volatility. To address this issue, a novel supramolecular deep eutectic electrolyte (DEE) has been developed, based on synergistic interaction between Li‐bonds and H‐bonds through a combination of lithium salt (LiTFSI), acetamide (Ace) and boric acid (BA). The incorporation of BA serves as an interface modification additive, acting as both Li‐bonds acceptor and H‐bonds donor/acceptor, thereby enhancing the redox stability of the electrolyte, facilitating a solution phase discharge process and improving compatibility with the Li anode. Our proposed DEE demonstrates a high oxidation voltage of 4.5 V, an ultrahigh discharge capacity of 15225 mAh g−1 and stable cycling performance of 196 cycles in LOBs. Additionally, the intrinsic non‐flammability and successful operation of a Li−O2 pouch cell indicate promising practical applications of this electrolyte. This research broadens the design possibilities for LOBs electrolytes and provides theoretical insights for future studies.