The aprotic lithium-oxygen (Li-O₂) battery has attracted worldwide attention because of its ultrahigh theoretical energy density. However, its practical application is critically hindered by cathode passivation, large polarization, and severe parasitic reactions. Here, we demonstrate an originally designed Ru(II) polypyridyl complex (RuPC) though which the reversible expansion of Li₂O₂ formation and decomposition can be achieved in Li-O₂ batteries. Experimental and theoretical results revealed that the RuPC can not only expand the formation of Li₂O₂ in electrolyte but also suppress the reactivity of LiO₂ intermediate during discharge, thus alleviating the cathode passivation and parasitic reactions significantly. In addition, an initial delithiation pathway can be achieved when charging in turn; thus, the Li₂O₂ products can be decomposed reversibly with a low overpotential. Consequently, the RuPC-catalyzed Li-O₂ batteries exhibited a high discharge capacity, a low charge overpotential, and an ultralong cycle life. This work provides an alternative way of designing the soluble organic catalysts for metal-O₂ batteries.

非质子锂氧（Li-O ₂）电池由于其极高的理论能量密度而引起了全世界的关注。然而，阴极钝化，大极化和严重的寄生反应严重地阻碍了它的实际应用。在这里，我们演示了最初设计的Ru（II）聚吡啶基络合物（RuPC），但在Li-O ₂电池中可以实现Li ₂ O ₂形成和分解的可逆扩展。实验和理论结果表明，RuPC不仅可以扩大电解质中Li ₂ O ₂的形成，而且可以抑制LiO ₂的反应性。放电过程中的中间产物，从而显着减轻了阴极钝化和寄生反应。另外，当依次充电时，可以实现初始的脱锂路径。因此，Li ₂ O ₂产物可以以低过电位可逆地分解。因此，RuPC催化的Li-O ₂电池显示出高放电容量，低充电过电势和超长循环寿命。这项工作为设计用于金属O ₂电池的可溶性有机催化剂提供了另一种方法。