To enhance the cycling and rate performances of SiO as an anode material, a CNT fiber-reinforced multi-carbon resource-coated SiOx composite (SiOx@MC/CNTs) prepared via a two-step pyrolysis process is evaluated. The SiOx@MC/CNTs composite exhibits a high initial coulombic efficiency of 74.6%, an initial charge capacity of 1400.5 mAh/g, and an initial discharge capacity of 1878.6 mAh/g. After 250 cycles, the composite shows a reversible capacity of 992.9 mAh/g, with a capacity retention rate of 70.9%. In addition, the composite obtains a good rate performance for the discharge capacities of 1381.3 mAh/g at 0.5 A/g and 1328.1 mAh/g at 1.0 A/g. The improved properties should be ascribed to the amorphous carbon layer and the CNT addition. The carbon layer prevents SiOx surface from direct contacting the electrolyte and adapts the volume change of SiOx particles during the repeated lithiation/delithiation process. The composite exhibits high conductivity of 4637.8 S/cm which is seven times higher than SiOx without the amorphous carbon layer and CNTs. This fabricating process can be a reference for the preparation of SiOx anode materials.

中文翻译：

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CNT纤维增强多碳资源包覆SiOx复合材料负极材料的研究

为了提高 SiO 作为负极材料的循环和倍率性能，评估了通过两步热解工艺制备的 CNT 纤维增强多碳资源包覆 SiOx 复合材料（SiOx@MC/CNTs）。SiOx@MC/CNTs复合材料的初始库仑效率高达74.6%，初始充电容量为1400.5 mAh/g，初始放电容量为1878.6 mAh/g。250次循环后，复合材料的可逆容量为992.9 mAh/g，容量保持率为70.9%。此外，该复合材料在 0.5 A/g 时的放电容量为 1381.3 mAh/g，在 1.0 A/g 时的放电容量为 1328.1 mAh/g。改进的性能应归因于无定形碳层和 CNT 添加。碳层防止 SiOx 表面直接接触电解质，并在重复的锂化/脱锂过程中适应 SiOx 颗粒的体积变化。该复合材料具有 4637.8 S/cm 的高电导率，比没有无定形碳层和 CNT 的 SiOx 高七倍。该制作工艺可为SiOx负极材料的制备提供参考。