Effect of cations in ionic liquids on the electrochemical performance of lithium-sulfur batteries

• Published in: Science China. Chemistry Vol. 57; no. 11; pp. 1564 - 1569
• Main Authors: Yan, Yang, Yin, YaXia, Guo, YuGuo, Wan, Li-Jun
• Format: Journal Article
• Language: English
• Published: Heidelberg Science China Press 01.11.2014; Springer Nature B.V
• Subjects: Cations; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Dissolution; Electrochemical analysis; Electrode materials; Ionic liquids; Lithium sulfur batteries; Nonaqueous electrolytes; Polysulfides; Rechargeable batteries; Room temperature; 可充电电池; 多硫化物; 室温离子液体; 循环稳定性; 有机电解质; 电化学性能; 离子对; 锂阳极; polysulfides; PMIMTFSI; lithium-sulfur batteries; electrolyte; P13TFSI
• ISSN: 1674-7291; 1869-1870
• DOI: 10.1007/s11426-014-5154-3

Lithium-sulfur（Li-S） battery is a promising choice for the next generation of high-energy rechargeable batteries, but its application is impeded by the high dissolution of the polysulfides in commonly used organic electrolyte. Room temperature ionic liquids（RTILs） have been considered as appealing candidates for the electrolytes in Li-S batteries. We investigated the effect of cations in RTILs on the electrochemical performance for Li-S batteries. Ex situ investigation of lithium anode for Li-S batteries indicates that during the discharge/charge process the RTIL with N-methyl-N-propylpyrrolidine cations（P13） can effectively suppress the dissolution of the polysulfides, whereas the RTIL with 1-methyl-3-propyl imidazolium cation（PMIM） barely alleviates the shuttling problem. With 0.5 mol L-1 LiTFSI/P13 TFSI as the electrolyte of Li-S battery, the ketjen black/ sulfur cathode material exhibits high capacity and remarkable cycling stability, which promise the application of the P13-based RTILs in Li-S batteries.