LAUSR

Abstract To achieve a long-cycle-life lithium-air battery, the catalyst, electrolyte and lithium anode should be optimized synergistically. Herein, we achieve a super-long cycle-life lithium-O2 battery by integrating the synergistic effect of highly active Pt3Co nanowires (PtCo NWs) cathode catalyst and stable quasi-solid SiO2-ionic liquid (IL) electrolyte. The PtCo NWs can effectively reduce the charge voltage below 3.2 V, but have to induce the decomposition of the conventional liquid electrolyte. The SiO2-IL electrolyte has a high ionic conductivity, but it still cannot match with carbonaceous oxygen electrode, due to its large charge overpotential. By combining the PtCo NWs cathode catalyst with quasi-solid electrolyte, the lithium-O2 battery can reversibly discharge and charge above 300 cycles (>3000 h). When the battery is disassembled, the lithium metal anode is preserved well, which is closely covered by a layer of SiO2 nanoparticles containing IL. By contrast, the lithium anode completely changes to the white powders for the one with ether-based electrolyte stored under the same condition, demonstrating the lithium anode is perfectly protected by the SiO2-IL electrolyte, which is a critical factor for achieving the long-life performance of lithium-O2 battery. Even under the air atmosphere, the battery can still cycle very well.