Xu Guiyin, Yan Qing-Bo, Wang Shitong, Kushima Akihiro, Bai Peng, Liu Kai, Zhang Xiaogang, Tang Zilong, Li Ju
Jiangsu Key Laboratory of Material and Technology for Energy Conversion , College of Material Science and Engineering , Nanjing University of Aeronautics and Astronautics , Nanjing 210016 , P. R. China . Email:
Department of Nuclear Science and Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , USA . Email:
Chem Sci. 2017 Sep 1;8(9):6619-6625. doi: 10.1039/c7sc01961k. Epub 2017 Jul 17.
Lithium-sulfur batteries are one of the most promising next-generation batteries due to their high theoretical specific capacity, but are impeded by the low utilization of insulating sulfur, unstable morphology of the lithium metal anode, and transport of soluble polysulfides. Here, by coating a layer of nano titanium dioxide and carbon black onto a commercial polypropylene separator, we demonstrate a new composite separator that can confine the polysulfides on the cathode side, forming a catholyte chamber, and at the same time block the dendritic lithium on the anode side. Lithium-sulfur batteries using this separator show a high initial capacity of 1206 mA h g and a low capacity decay rate of 0.1% per cycle at 0.5C. Analyses reveal the electrocatalytic effect and the excellent dendrite-blocking capability of the ∼7 µm thick coating.
锂硫电池因其高理论比容量而成为最具前景的下一代电池之一，但受到绝缘硫利用率低、锂金属负极形态不稳定以及可溶性多硫化物传输等问题的阻碍。在此，通过在商用聚丙烯隔膜上涂覆一层纳米二氧化钛和炭黑，我们展示了一种新型复合隔膜，它可以将多硫化物限制在阴极侧，形成一个阴极电解液腔，同时在阳极侧阻挡锂枝晶。使用这种隔膜的锂硫电池在0.5C时显示出1206 mA h g的高初始容量和每循环0.1%的低容量衰减率。分析揭示了约7 µm厚涂层的电催化作用和优异的枝晶阻挡能力。
