Solution Ionic Strength Engineering As a Generic Strategy to Coat Graphene Oxide (GO) on Various Functional Particles and Its Application in High-Performance Lithium-Sulfur (Li-S) Batteries
Solution Ionic Strength Engineering As a Generic Strategy to Coat Graphene Oxide (GO) on Various Functional Particles and Its Application in High-Performance Lithium-Sulfur (Li-S) Batteries
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DOI：
10.1021/nl403404v
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发表时间：
2014-02-01
期刊：
影响因子：
10.8
通讯作者：
Zhou, Chongwu
中科院分区：
文献类型：
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作者：
Rong, Jiepeng;Ge, Mingyuan;Zhou, Chongwu
报道了一种在颗粒上包覆氧化石墨烯（GO）的通用且简便的方法，其中硫/GO核-壳颗粒作为具有上级性能的锂-硫（Li-S）电池应用的示例被展示。通过设计溶液中的离子强度，GO成功地包裹了不同直径（从100 nm到10 μ m）、几何形状和组成（硫、硅和碳）的颗粒。重要的是，我们的方法不涉及GO和包裹颗粒之间的任何化学反应，因此，它可以扩展到各种功能颗粒。进一步研究了硫/GO核壳粒子作为锂硫电池正极材料的应用，结果表明，与未包覆的裸硫粒子相比，硫/GO核壳粒子表现出显著的性能改善。使用GO/硫颗粒的电流充放电测试显示，如果仅考虑硫的质量，则在1A/g电流速率下1000次循环后保持800 mAh/g的比容量，如果考虑硫/GO的总质量，则保持400 mAh/g的比容量。最重要的是，超过1000次循环的容量衰减小于每循环0.02%。在这项研究中开发的涂层方法是方便，强大的，和通用的，预计将有广泛的应用在改善颗粒材料的性能。
A generic and facile method of coating graphene oxide (GO) on particles is reported, with sulfur/GO core-shell particles demonstrated as an example for lithium-sulfur (Li-S) battery application with superior performance. Particles of different diameters (ranging from 100 nm to 10 mu m), geometries, and compositions (sulfur, silicon, and carbon) are successfully wrapped up by GO, by engineering the ionic strength in solutions. Importantly, our method does not involve any chemical reaction between GO and the wrapped particles, and therefore, it can be extended to vast kinds of functional particles. The applications of sulfur/GO core-shell particles as Li-S battery cathode materials are further investigated, and the results show that sulfur/GO exhibit significant improvements over bare sulfur particles without coating. Galvanic charge-discharge test using GO/sulfur particles shows a specific capacity of 800 mAh/g is retained after 1000 cycles at 1 A/g current rate if only the mass of sulfur is taken into calculation, and 400 mAh/g if the total mass of sulfur/GO is considered. Most importantly, the capacity decay over 1000 cycles is less than 0.02% per cycle. The coating method developed in this study is facile, robust, and versatile and is expected to have wide range of applications in improving the properties of particle materials.