Ternary graphene/sulfur/SiO2 composite as stable cathode for high performance lithium/sulfur battery
Ternary graphene/sulfur/SiO2 composite as stable cathode for high performance lithium/sulfur battery
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DOI：
10.1016/j.ijhydene.2015.09.062
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发表时间：
2016-01
影响因子：
7.2
通讯作者：
W. Pan;M. Fan;H. Chen;Da Chen;C. Li;K. Shu;Chunju Lv
中科院分区：
文献类型：
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作者：
W. Pan;M. Fan;H. Chen;Da Chen;C. Li;K. Shu;Chunju Lv
将硫磺与石墨烯复合，再包覆SiO_2，成功地合成了石墨烯/硫/SiO_2(石墨烯/S/SiO_2)三元复合材料。石墨烯/S/二氧化硅复合材料作为锂硫电池正极材料时，由于石墨烯和二氧化硅的共同作用，表现出优异的比容量和循环稳定性。石墨烯/S/二氧化硅经活化后的比容量为696mAhg−1，明显高于石墨烯/S和纯硫样品。此外，由于成功地阻止了多硫化物的扩散，石墨烯/S/二氧化硅和石墨烯/S复合材料表现出比纯硫样品更好的循环稳定性和更高的库仑效率。此外，石墨烯/S/二氧化硅和石墨烯/S复合材料在前30个循环中都出现了活化步骤，这可以归因于容量从高阶多硫化物还原到低阶多硫化物的逐渐增加。
Ternary graphene/sulfur/SiO2(graphene/S/SiO2) composite has been successfully synthesized by compositing sulfur with graphene and then wrapping with SiO2. The graphene/S/SiO2composite exhibits superior specific capacity and improved cycling stability owing to the combined contributions from both graphene and SiO2when used as cathode materials for lithium/sulfur batteries. The graphene/S/SiO2demonstrates a specific capacity of 696 mAh g−1after activated, which is considerably higher than the graphene/S and pure sulfur samples. In addition, the graphene/S/SiO2and graphene/S composites demonstrate improved cycling stability and much higher coulombic efficiency than the pure sulfur sample owing to the successful prevention of polysulfides diffusion. Furthermore, both graphene/S/SiO2and graphene/S composites show an activation step in first 30 cycles, which can be attributed to the gradually increased capacity from reduction of high-order polysulfides to low-order polysulfides.