Abstract Silicon anode usually exhibits high capacity, good initial coulombic efficiency, but poor cycle performance. While the extra oxygen in SiO can significantly contribute to the cyclic stability but at the cost of initial coulombic efficiency. Therefore oxygen content plays a key role in the performance balance of silicon-based anode materials. In order to demonstrate the influence of oxygen content on the electrochemical performance of SiOx-based anodes, different O/Si ratio of SiOx@C composites (x = 0.95, 0.81, 0.71 and 0.61) have been synthesized through magnesiothermic reduction process. It is found that the SiO0.81@C composite exhibits the most excellent electrochemical performance with an initial reversible capacity of 1374 mA h/g and an ICE of 73%. After 200 cycles, the composite shows a reversible capacity of 1230 mA h/g with a capacity retention rate of ∼90%. The results indicate that the rational O/Si ratio can realize the balance between cycling stability and ICE of SiOx anodes. This study can provide practical guidance for the design of SiOx-based anodes for Li-ion batteries.

中文翻译：

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氧含量对锂离子电池SiOx@C负极电化学行为的影响

摘要 硅负极通常具有高容量、良好的初始库仑效率，但循环性能较差。虽然 SiO 中的额外氧可以显着促进循环稳定性，但以初始库仑效率为代价。因此，氧含量在硅基负极材料的性能平衡中起着关键作用。为了证明氧含量对 SiOx 基负极电化学性能的影响，通过镁热还原工艺合成了不同 O/Si 比的 SiOx@C 复合材料（x = 0.95、0.81、0.71 和 0.61）。结果表明，SiO0.81@C 复合材料表现出最优异的电化学性能，初始可逆容量为 1374 mA h/g，ICE 为 73%。200 次循环后，该复合材料的可逆容量为 1230 mA h/g，容量保持率约为 90%。结果表明合理的O/Si比可以实现SiOx负极的循环稳定性和ICE之间的平衡。该研究可为锂离子电池的 SiOx 基负极设计提供实用指导。