A stable graphite electrode in superconcentrated LiTFSI-DME/DOL electrolyte and its application in lithium-sulfur full battery

作者：Zeng, Pan; Han, Yamiao; Duan, Xiaobo; Jia, Guichong; Huang, Liwu^*; Chen, Yungui^*

来源：Materials Research Bulletin, 2017, 95: 61-70.

DOI：10.1016/j.materresbull.2017.07.018

• Lithium-sulfur full batteries
• Graphite electrode
• Superconcentrated ether electrolyte
• Sulfur cathode
• Cycle stability

Herein, prelithiated graphite anodes are coupled with sulfur composite cathodes to form a Li-S full cell in superconcentrated ether electrolyte. This novel system is effective in avoiding sever corrosion of Li-metal anode and significantly improving the safety of present Li-S cell, owing to the replacement of Li-metal anode with graphite. The introduced superconcentrated ether electrolyte has a unique networking structure of Li cations and TFSI anions with Li+-solvating DME/DOL solvents, which is conducive to form a stable TFSI-derived surface film on the graphite electrode. The stable and dense TFSI-derived film inhibits further electrolyte decomposition and graphite exfoliation caused by co-intercalation of solvents, allowing reversible lithium intercalation and de-intercalation at a graphite electrode. Besides, the severe polysulfides shuttle is also suppressed by the concentrated ether-based solutions. Consequently, the assembled graphite-sulfur full battery retains outstanding capacity of 686 mAh g(sulfur)(-1) at 0.1C rate after 105 cycles, along with high Coulombic efficiency.

• 出版日期2017-11
• 单位四川大学