Fibrous Hybrid of Graphene and Sulfur Nanocrystals for High-Performance Lithium-Sulfur Batteries
Fibrous Hybrid of Graphene and Sulfur Nanocrystals for High-Performance Lithium-Sulfur Batteries
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DOI：
10.1021/nn401228t
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发表时间：
2013-06-01
期刊：
影响因子：
17.1
通讯作者：
Cheng, Hui-Ming
中科院分区：
文献类型：
--
作者：
Zhou, Guangmin;Yin, Li-Chang;Cheng, Hui-Ming
采用硫/二硫化碳/乙醇混合溶液，通过一锅法制备了硫纳米晶锚定在纤维状石墨烯上的石墨烯-硫（GS）杂化材料.氧化石墨烯的还原和硫纳米晶体的形成/结合是一体化的。G-S杂化物表现出由纤维状石墨烯构建的高度多孔的网络结构、许多导电通路和容易调节的硫含量，其可以被切割和压制成粒料以直接用作锂硫电池阴极而不使用金属集流体、粘合剂和导电添加剂。多孔网络和硫纳米晶体能够实现快速的离子传输和短的Li+扩散距离，互连的纤维状石墨烯提供高导电性的电子传输路径，并且含氧（主要是羟基/环氧基）基团显示出与多硫化物的强结合，防止它们溶解到基于第一原理计算的电解质中。因此，G-S混合动力车表现出高容量、优异的高倍率性能和超过100次循环的长寿命。这些结果证明了这种独特的混合结构作为高性能锂硫电池阴极的巨大潜力。
Graphene-sulfur (G S) hybrid materials with sulfur nanocrystals anchored on interconnected fibrous graphene are obtained by a facile one-pot strategy using a sulfur/carbon disulfide/ alcohol mixed solution. The reduction of graphene oxide and the formation/binding of sulfur nanocrystals were integrated. The G S hybrids exhibit a highly porous network structure constructed by fibrous graphene, many electrically conducting pathways, and easily tunable sulfur content, which can be cut and pressed into pellets to be directly used as lithium sulfur battery cathodes without using a metal current-collector, binder, and conductive additive. The porous network and sulfur nanocrystals enable rapid Ion transport and short Li+ diffusion distance, the Interconnected fibrous graphene provides highly conductive electron transport pathways, and the oxygen-containing (mainly hydroxyl/epoxide) groups show strong binding with polysulfides, preventing their dissolution into the electrolyte based on first-principles calculations. As a result, the G S hybrids show a high capacity, an excellent high-rate performance, and a long life over 100 cycles. These results demonstrate the great potential of this unique hybrid structure as cathodes for high-performance lithium sulfur batteries.