Abstract It was demonstrated that the electrochemical performance enhancements in KOH-activated carbon materials should be mainly due to the created polar oxygen-containing functional groups (OFGs, such as such as C–O, C O, –OH, and O–C O), while the role of each OFGs on the electrochemical enhancements is still unclear. In this work, KOH activation treatments were systematically conducted on carbon nanotubes (CNTs) to explore the role of each OFG on the performance enhancements of Li–S batteries (LSBs). Results showed that the capacity of activated-CNT-sulfur (a-CNT-S) cathodes is 33% higher than that of the pristine CNT-S cathodes, and their rate capability and cycling stability are also enhanced. And the electrochemical analysis combining with Fourier transform infrared spectroscopy indicated that the formed C–O bonds are the real factor for the enhanced electrochemical performances of a-CNT-S cathodes. Furthermore, the optimal activation conditions on CNT-based cathodes for LSBs were optimized to be 10 min at 700 °C.

中文翻译：

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使用傅里叶变换红外光谱研究通过活化多壁碳纳米管上的含氧官能团增强锂硫电池的性能

摘要 结果表明，KOH 活性炭材料的电化学性能增强主要是由于产生了极性含氧官能团（OFG，如 C-O、CO、-OH 和 O-CO），而每种 OFG 对电化学增强的作用仍不清楚。在这项工作中，系统地对碳纳米管 (CNT) 进行了 KOH 活化处理，以探索每种 OFG 对 Li-S 电池 (LSB) 性能增强的作用。结果表明，活性碳纳米管硫（a-CNT-S）正极的容量比原始碳纳米管硫正极的容量高 33%，并且其倍率性能和循环稳定性也得到了提高。结合傅里叶变换红外光谱的电化学分析表明，形成的 C-O 键是提高 a-CNT-S 正极电化学性能的真正因素。此外，用于 LSB 的基于 CNT 的阴极的最佳活化条件被优化为 700 °C 下 10 分钟。