National & Local United Engineering Laboratory for Power Batteries, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , P. R. China.
ACS Appl Mater Interfaces. 2018 Aug 8;10(31):26312-26319. doi: 10.1021/acsami.8b08346. Epub 2018 Jul 24.
Developing a long-term stable electrolyte is one of the most enormous challenges for Li-O batteries. Equally, the high flammability of frequently used solvents seriously weakens the electrolyte safety in Li-O batteries, which inevitably restricts their commercial applications. Here, a binary mixture of highly concentrated tetraglyme electrolyte (HCG4) and 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) was used for a novel electrolyte (HCG4/TTE) in Li-O batteries, which exhibit good wettability, enhanced ionic conductivity, considerable nonflammability, and high electrochemical stability. Being a co-solvent, TTE can contribute to increasing ionic conductivity and to improving flame retardance of the as-prepared electrolyte. The cell with this novel electrolyte displays an enhanced cycling stability, resulting from the high electrochemical stability during cycling and the formation of electrochemically stable interfaces prevents parasitic reactions occurring on the Li anode. These results presented here demonstrate a novel electrolyte with a high electrochemical stability and considerable safety for Li-O batteries.
开发长期稳定的电解质是锂氧电池面临的最大挑战之一。同样，常用溶剂的高可燃性严重削弱了锂氧电池中的电解质安全性，这不可避免地限制了它们的商业应用。在这里，高浓度四甘醇电解质（HCG4）和 1,1,2,2-四氟乙基 2,2,3,3-四氟丙基醚（TTE）的二元混合物被用于锂氧电池中的新型电解质（HCG4/TTE），它具有良好的润湿性、增强的离子导电性、相当的不可燃性和高电化学稳定性。作为共溶剂，TTE 可以提高离子导电性并改善所制备电解质的阻燃性。使用这种新型电解质的电池表现出增强的循环稳定性，这归因于循环过程中的高电化学稳定性以及形成电化学稳定的界面，阻止了在 Li 阳极上发生寄生反应。这些结果表明，对于锂氧电池来说，这种新型电解质具有高电化学稳定性和相当高的安全性。
