Chen Ruoxi, Zhou Yucheng, Li Xiaodong
Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, Virginia 22904-4746, United States.
Nano Lett. 2022 Feb 9;22(3):1217-1224. doi: 10.1021/acs.nanolett.1c04380. Epub 2022 Jan 21.
Fabrication processes of fossil fuel-derived carbon nanomaterials are of high carbon emissions. Deriving carbon materials from low-cost and sustainable biomass is eco-friendly. Cotton, one of the most abundant biomass materials, naturally holds a hierarchically porous structure, making the activated cotton textile (ACT) an ideal scaffold for loading active materials. Here, we report a low-cost approach to massively producing multiwalled carbon nanotubes (MWCNTs) via a combination process of vapor-liquid-solid (VLS) and solid-liquid-solid (SLS) where cotton decomposed into carbon-containing gases and amorphous carbons that then dissolved into Fe nanoparticles, forming Fe/FeC-encapsulated MWCNTs. The lithium-sulfur (Li-S) battery constructed by the Fe/FeC-MWCNT@ACT/S composite (as the cathode) and the Fe/FeC-MWCNT@ACT (as the interlayer) exhibited a superlative cycling stability (over 1000 cycles at 1.0 C), an ultralow capacity decay rate (0.0496% per cycle) and a remarkable specific capacity (1273 mAh g at 0.1 C). The Fe/FeC-MWCNTs enhanced electrode stability and suppressed polysulfide dissolution during cycling.
化石燃料衍生的碳纳米材料的制造过程碳排放量大。从低成本且可持续的生物质中获取碳材料则较为环保。棉花是最丰富的生物质材料之一，天然具有分级多孔结构，这使得活性棉织物（ACT）成为负载活性材料的理想支架。在此，我们报道一种低成本方法，通过气-液-固（VLS）和固-液-固（SLS）的组合过程大规模生产多壁碳纳米管（MWCNT），其中棉花分解为含碳气体和无定形碳，然后溶解到铁纳米颗粒中，形成Fe/FeC封装的MWCNT。由Fe/FeC-MWCNT@ACT/S复合材料（作为阴极）和Fe/FeC-MWCNT@ACT（作为中间层）构建的锂硫（Li-S）电池表现出卓越的循环稳定性（在1.0 C下超过1000次循环）、超低的容量衰减率（每循环0.0496%）和显著的比容量（在0.1 C下为1273 mAh g）。Fe/FeC-MWCNT增强了电极稳定性并抑制了循环过程中的多硫化物溶解。
