A S/DPAN (dehydrogenated polyacrylonitrile) composite shows promising electrode performances as a cathode material for Li-S batteries though its electric conductivity is insufficient for high rate tests. In an attempt to enhance the electric conductivity, the S/DPAN composite is attached on reduced graphene oxide (rGO) sheets via self-assembling modification. As a result, the conductivity improves to ∼10⁻⁴ S cm⁻¹, and the S/DPAN/rGO composite thereby delivers approximately 90% of the theoretical capacity of sulphur at a rate of 0.2C (0.34 A g⁻¹) over 700 mAh (g-S)⁻¹ even at 2C (3.4 A g⁻¹). We first report on the CS bond between sulphur and DPAN in a composite that maintains the bond even after an extensive cycling test, as confirmed by time-of-flight secondary-ion mass spectroscopy (ToF-SIMS). These synergistic effects enable facile electron transport such that the S/DPAN/rGO composite electrode is able to maintain superior electrode performances.

中文翻译：

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碳硫键在硫/脱氢聚丙烯腈/还原型氧化石墨烯复合正极中的作用

尽管AS / DPAN（脱氢聚丙烯腈）复合材料的电导率不足以进行高倍率测试，但其作为Li-S电池正极材料的电极性能显示出良好的前景。为了增强导电性，S / DPAN复合材料通过自组装改性而附着在还原的氧化石墨烯（rGO）板上。结果，电导率提高到〜10 ^-4 S cm ^-1，并且S / DPAN / rGO复合材料以0.2C（0.34 A g ^-1）的速率输送了约90％的理论硫容量。700 mAh（gS）^-1（即使在2C（3.4 A g ^-1）。我们首先报告了复合材料中硫与DPAN之间的CS键，即使经过广泛的循环测试，该键仍可保持该键，这已通过飞行时间二次离子质谱（ToF-SIMS）确认。这些协同效应使电子传输变得容易，使得S / DPAN / rGO复合电极能够保持优异的电极性能。