The non-aqueous rechargeable lithium-oxygen batteries (LOBs) are one of the most promising candidates for future electric vehicles and wearable/flexible electronics. However, its development is severely hindered by the sluggish kinetics of ORR and OER during discharge and charge processes. Here, we employ MOF assisted spatial confinement and ionic substitution strategies to synthesize Ru single-atoms riveted with nitrogen-doped porous carbon (Ru SAs-NC) as the electrocatalytic material. By using the optimized Ru0.3 SAs-NC as electrocatalysts in the oxygen-breathing electrodes, the developed LOB can deliver the lowest overpotential of only 0.55 V at 0.02 mA cm-2. Moreover, in-situ DEMS results quantify that the e-/O2 ratio of LOBs in a full cycle is only 2.14, indicating a superior electrocatalytic performance in LOB applications. Theoretical calculations reveal that the Ru-N4 serves as the driving force center and the amount of this configuration can significantly affect the internal affinity of intermediate species. The rate limiting step of ORR on the catalyst surface is the occurrence of 2e- reactions to generate Li2O2, while the OER pathway is the oxidation of Li2O2. This work broadens the field of vision for the design of single-site high-efficiency catalysts with maximum atomic utilization efficiency for LOBs.

中文翻译：

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通过空间限制和离子取代策略在 N 掺杂碳上的 Ru 单原子用于高性能 Li-O2 电池

非水可充电锂氧电池 (LOB) 是未来电动汽车和可穿戴/柔性电子产品最有希望的候选者之一。然而，它的发展受到放电和充电过程中 ORR 和 OER 缓慢动力学的严重阻碍。在这里，我们采用 MOF 辅助的空间限制和离子取代策略来合成用掺氮多孔碳 (Ru SAs-NC) 作为电催化材料铆接的 Ru 单原子。通过使用优化的 Ru0.3 SAs-NC 作为吸氧电极中的电催化剂，开发的 LOB 可以在 0.02 mA cm-2 下提供仅 0.55 V 的最低过电位。此外，原位 DEMS 结果量化了整个循环中 LOB 的 e-/O2 比仅为 2.14，表明在 LOB 应用中具有优异的电催化性能。理论计算表明，Ru-N4 作为驱动力中心，这种配置的数量可以显着影响中间物种的内部亲和力。催化剂表面 ORR 的限速步骤是发生 2e-反应生成 Li2O2，而 OER 途径是 Li2O2 的氧化。这项工作拓宽了设计具有最大原子利用率的 LOB 单中心高效催化剂的视野。