Spherical Macroporous Carbon Nanotube Particles with Ultrahigh Sulfur Loading for Lithium-Sulfur Battery Cathodes
Spherical Macroporous Carbon Nanotube Particles with Ultrahigh Sulfur Loading for Lithium-Sulfur Battery Cathodes
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DOI：
10.1021/acsnano.7b05869
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发表时间：
2018-01-01
期刊：
影响因子：
17.1
通讯作者：
Moon, Jun Hyuk
中科院分区：
文献类型：
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作者：
Gueon, Donghee;Hwang, Jeong Tae;Moon, Jun Hyuk
能够有效、均匀地负载硫的碳基材料是锂硫电池的关键。尽管应用了各种形貌的多孔炭材料，但能够均匀浸渍高活性硫的碳基质仍然具有挑战性。为了解决这个问题，我们展示了一种分层的孔道结构的碳纳米管颗粒宿主，其中包含数百纳米的球形大孔。大孔碳纳米管颗粒(M-CNTP)是将碳纳米管和聚合物颗粒分散在气溶胶液滴中干燥而成。在硫的熔体扩散过程中，球形大孔极大地促进了硫向碳载体的渗透。此外，大孔的形成极大地扩大了碳纳米管束之间的微孔体积。因此，我们均匀浸渍70wt%的硫磺，没有硫磺残留物。S-M-碳纳米管阴极在0.2C的电流密度下，即使在70wt%的高硫含量下也表现出1343 mA·h~(-1)的高可逆容量。当电流密度增加10倍时，高容量保持率可达74%。这些阴极的硫含量高于传统碳纳米管的阴极，但仍表现出优异的性能。我们的碳纳米管和孔控制技术将推动碳纳米管主体用于LSB的商业化。
A carbon host capable of effective and uniform sulfur loading is the key for lithium-sulfur batteries (LSBs). Despite the application of porous carbon materials of various morphologies, the carbon hosts capable of uniformly impregnating highly active sulfur is still challenging. To address this issue, we demonstrate a hierarchical pore-structured CNT particle host containing spherical macropores of several hundred nanometers. The macropore CNT particles (M-CNTPs) are prepared by drying the aerosol droplets in which CNTs and polymer particles are dispersed. The spherical macropore greatly improves the penetration of sulfur into the carbon host in the melt diffusion of sulfur. In addition, the formation of macropores greatly develops the volume of the micropore between CNT strands. As a result, we uniformly impregnate 70 wt % sulfur without sulfur residue. The S-M-CNTP cathode shows a highly reversible capacity of 1343 mA h g(-1) at a current density of 0.2 C even at a high sulfur content of 70 wt %. Upon a 10-fold current density increase, a high capacity retention of 74% is observed. These cathodes have a higher sulfur content than those of conventional CNT hosts but nevertheless exhibit excellent performance. Our CNTPs and pore control technology will advance the commercialization of CNT hosts for LSBs.