Transition metal compounds with complex compositions forming heterointerfaces during cycling are under development on account of their excellent electrochemical properties. Herein, a new synthesis strategy is successfully developed for uniquely structured hollow carbon nanospheres comprising amorphous CoSeO_x nanoparticles. A drop-and-dry infiltration method is applied to synthesize metal salt-infiltrated hollow carbon nanospheres, which are then posttreated with a metalloid Se under inert conditions to form CoSe₂–C hollow nanospheres. Partial oxidation of these nanospheres under a 350 °C air atmosphere produces amorphous CoSeO_x–C hollow nanospheres. The synthesis of amorphous metal selenite using conductive carbon is being reported here for the first time. Moreover, the conversion mechanism of amorphous CoSeO_x is studied systemically via ex situ X-ray photoelectron spectroscopy, transmission electron microscopy, and electrochemical analyses. The amorphous characteristics and heterostructure formation and the graphitic carbon with a good electric conductivity contribute to the good electrochemical kinetic performance and ultrastable cyclic stability of CoSeO_x–C. CoSeO_x–C shows remarkable long-term cycle performance (799 mA h g^–1 for the 3000th cycle at a high current density of 5.0 A g^–1) as well as remarkable rate capability (691 mA h g^–1) even at 30 A g^–1.

中文翻译：

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石墨碳空心壳上装饰的非晶亚硒酸钴纳米粒子，用于高速率和超长循环寿命的锂离子电池

由于其优异的电化学性能，具有在循环期间形成异质界面的复杂组成的过渡金属化合物正在开发中。本文中，针对包含无定形CoSeO _x纳米颗粒的独特结构的中空碳纳米球，成功开发了一种新的合成策略。采用干式渗透法合成了金属盐浸渗的中空碳纳米球，然后在惰性条件下用准金属Se进行后处理，形成CoSe ₂ -C中空纳米球。在350°C的空气气氛下，这些纳米球的部分氧化产生非晶态的CoSeO _x-C空心纳米球。本文首次报道了使用导电碳合成非晶态金属亚硒酸盐。此外，通过异位X射线光电子能谱，透射电子显微镜和电化学分析系统地研究了非晶态CoSeO _x的转化机理。非晶态特征和异质结构的形成以及具有良好电导率的石墨碳有助于CoSeO _x –C的良好电化学动力学性能和超稳定的循环稳定性。CoSeO _X -C显示显着的长期循环性能（799毫安汞柱^-1在5.0的高电流密度的第3000周期A G ^-1）以及卓越的速率能力（691 mA hg ^–1），即使在30 A g ^{–1的情况下也是如此}。