标题：SnS2- Compared to Sn0(2)-Stabilized S/C Composites toward High Performance Lithium Sulfur Batteries
作者：Li, Xiaona; Lu, Yue; Hou, Zhiguo; Zhang, Wanqun; Zhu, Yongchun; Qian, Yitai; Liang, Jianwen; Qian, Yitai
作者机构：[Li, Xiaona; Lu, Yue; Hou, Zhiguo; Zhang, Wanqun; Zhu, Yongchun; Qian, Yitai] Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Dept Chem, 更多
通讯作者地址：[Zhu, YC; Qian, YT]Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Dept Chem, 96 JinZhai Rd, Hefei 230026, Peoples R China.
来源：ACS APPLIED MATERIALS & INTERFACES
关键词：tin disulfide; tin dioxide; lithium sulfur batteries; energy storage;; chemical interaction
摘要：The common sulfur/carbon(S/C) composite cathodes in lithium sulfur batteries suffer gradual capacity fading over long-term cycling incurred by the poor physical confinement of sulfur in a nonpolar carbon host. In this work, these issues are significantly relieved by introducing polar SnO2, or SnS2 species into the S/C composite. SnO2- or SnS2-stabilized sulfur in porous carbon composites (SnO2/S/C and SnS2/S/C) have been obtained through a baked-in-salt or sealed-in-vessel approach at 245 degrees C, starting from metallic tin (mp 231.89 degrees C), excess sulfur, and porous carbon. Both of the in situ-formed SnO2 and SnS2 in the two composites could ensure chemical interaction with lithium polysulfide (LiPS) intermediates proven by theoretical calculation. Compared to SnO2/S/C, the SnS2/S/C sample affords a more appropriate binding effect and shows lower charge transfer resistance, which is important for the efficient redox reaction of the adsorbed LiPS intermediates during cycling. When used as cathodes for Li-S batteries, the SnS2/S/C composite with sulfur loading of 78 wt % exhibits superior electrochemical performance. It delivers reversible capacities of 780 mAh after 300 cycles at 0.5 C. When further coupled with a Ge/C anode, the full cell also shows good cycling stability and efficiency.