Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
Nanotechnology. 2018 Nov 16;29(46):465401. doi: 10.1088/1361-6528/aadd65. Epub 2018 Aug 29.
The poor conductivity of sulfur and the shuttle effect of soluble polysulfides have considerably hindered the practical application of lithium-sulfur (Li-S) batteries. Here, we have fabricated a three-dimensional graphitic carbon nitride/reduced graphene oxide (GCN@rGO) network as the sulfur host in Li-S batteries, where the bifunctional GCN strongly binds polysulfides through a chemical interaction and catalyzes the redox reactions of polysulfides. Additionally, GCN coating is also applied to different membranes and when these GCN-coated-membranes (GCMs) are used as separators, they are found to effectively act as the polysulfide barrier to suppress the diffusion of polysulfide intermediates to the Li anode and thus ameliorate the shuttle effect. As a result, the Li-S battery assembled from the GCN@rGO/S cathode and GCM separator exhibited a high initial specific capacity of 1000.6 mAh g at 0.1 C and 87% capacity retention with 0.066% decay per cycle over 200 charge-discharge cycles at 0.5 C.
硫的导电性差和可溶性多硫化物的穿梭效应极大地阻碍了锂硫（Li-S）电池的实际应用。在这里，我们制备了一种三维石墨相氮化碳/还原氧化石墨烯（GCN@rGO）网络作为 Li-S 电池中的硫主体，其中双功能 GCN 通过化学相互作用强烈结合多硫化物，并催化多硫化物的氧化还原反应。此外，GCN 涂层也应用于不同的膜上，当这些 GCN 涂层膜（GCM）用作隔板时，它们被发现可以有效地作为多硫化物阻隔层，抑制多硫化物中间体向 Li 阳极的扩散，从而改善穿梭效应。结果，由 GCN@rGO/S 阴极和 GCM 隔板组装的 Li-S 电池在 0.1 C 时具有 1000.6 mAh g 的初始比容量，在 0.5 C 时经过 200 次充放电循环后，容量保持率为 87%，衰减率为每循环 0.066%。
