Design of ionic liquid-based hybrid electrolytes with additive for lithium insertion in graphite effectively and their effects on interfacial properties

作者：Guo, Qingpeng^*; Han, Yu^*; Wang, Hui; Xiong, Shizhao; Liu, Shuangke; Li, Yujie; Zheng, Chunman; Xie, Kai

来源：Ionics, 2018, 24(9): 2601-2609.

DOI：10.1007/s11581-017-2393-2

• Ionic liquid-based hybrid electrolytes
• Graphite negative electrode
• Additive
• Solid electrolyte interphase
• Safer Li-ion batteries

To address the challenge of the IL-based electrolyte cannot be effectively intercalated in graphite anode, and especially the urgent needs for the compatibility between high performance and high security, the IL-based hybrid electrolyte systems with ethylene carbonate/propylene carbonate (EC/PC) as a co-solvent and vinylene carbonate (VC) as an additive were designed. The high dielectric constant of EC/PC significantly increased the ionic conductivity and lithium ion migration of the electrolyte system. Meanwhile, the presence of VC can form SEI preventing EC and PYR14 (+) reductive decomposition on the electrode interface, and at the same moment, the SEI promotes effective Li cation insertion into the graphene interlayer. The Li/C half-cells showed high reversible capacity, cycling efficiency, and good cycle stability with the IL-based hybrid electrolyte. It is worth to highlight the better performance, in terms of the excellent thermal stability and high safety. Thus, the IL-based hybrid electrolyte combined with good electrochemical performance holds substantial promise for lithium-ion battery, and should have broad application prospects in the high energy density, especially high-security requirements, of the new lithium-ion battery.

• 出版日期2018-9
• 单位中国人民解放军国防科学技术大学