Ultra-small MnCo2O4 nanocrystals/nitrogen enriched carbon nanofiber composites, with particle size as small as 2–4[Formula: see text]nm and nitrogen content as high as [Formula: see text][Formula: see text]at.%, were designed and used as oxygen cathode materials for Li-O2 batteries, with an aprotic electrolyte. Via an in-situ nucleation and growth, the morphology, size and distribution of MnCo2O4 nanocrystals were well controlled on surface of nanofibers, with strong interfacial interactions between the two components. Benefitting from the unique microstructure and high-level nitrogen doping, the MnCo2O4/NCF composite can deliver discharge and charge capacities of 4147.8 and 3842.8[Formula: see text]mAh/g as oxygen cathode materials, and columbic efficiencies are about 92.6%. More importantly, the discharge products can completely decompose in charging process as evidenced by an ex-situ FESEM investigation, while for pure NCF cathode, particle and plate-like Li2O2 were still observed on its surface, which confirmed that the MnCo2O4/NCF composite has a superior electrocatalytic activity that that of NCF.

中文翻译：

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装饰在富氮碳纳米纤维上的超小 MnCo2O4 纳米晶体作为 Li-O2 电池的氧阴极

超小型MnCo2○4设计并使用了纳米晶/富氮碳纳米纤维复合材料，粒径小至2-4[公式：见正文]nm，氮含量高达[公式：见正文][公式：见正文]at.%作为Li-O的氧正极材料2电池，带有非质子电解质。通过原位成核和生长，MnCo 的形态、尺寸和分布2○4纳米晶体在纳米纤维表面得到很好的控制，两种组分之间具有很强的界面相互作用。得益于独特的微观结构和高水平的氮掺杂，MnCo2○4/NCF复合材料作为氧正极材料可提供4147.8和3842.8[公式：见正文]mAh/g的充放电容量，库比效率约为92.6%。更重要的是，通过非原位 FESEM 研究证明，放电产物可以在充电过程中完全分解，而对于纯 NCF 正极、颗粒和片状锂2○2在其表面仍然可以观察到，这证实了 MnCo2○4/NCF复合材料具有优于NCF的电催化活性。