Zhang Shengjie, Li Junhao, Jiang Ningyi, Li Xuqiu, Pasupath Sivakumar, Fang Yanxiong, Liu Quanbing, Dang Dai
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China.
Tianjin Institute of Power Sources, Tianjin Space Power Technology Co., Ltd., Tianjin, 300000, China.
Chem Asian J. 2019 Aug 16;14(16):2810-2814. doi: 10.1002/asia.201900581. Epub 2019 Jul 24.
It is a very urgent and important task to improve the safety and high-temperature performance of lithium/lithium-ion batteries (LIBs). Here, a novel ionic liquid, 1-(2-ethoxyethyl)-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (PYR TFSI), was designed and synthesized, and then mixed with dimethyl carbonate (DMC) as appropriate solvent and LiTFSI lithium salt to produce an electrolyte with high ionic conductivity for safe LIBs. Various characterizations and tests show that the highly flexible ether group could markedly reduce the viscosity and provide coordination sites for Li-ion, and the DMC could reduce the viscosity and effectively enhance the Li-ion transport rate and transference number. The electrolyte exhibits excellent electrochemical performance in Li/LiFeO cells at room temperature as well as at a high temperature of 60 °C. More importantly, with the addition of DMC, the IL-based electrolyte remains nonflammable and appropriate DMC can effectively inhibit the growth of lithium dendrites. Our present work may provide an attractive and promising strategy for high performance and safety of both lithium and lithium-ion batteries.
提高锂/锂离子电池（LIBs）的安全性和高温性能是一项非常紧迫且重要的任务。在此，设计并合成了一种新型离子液体1-(2-乙氧基乙基)-1-甲基吡咯烷双（三氟甲基磺酰）亚胺（PYR TFSI），然后将其与碳酸二甲酯（DMC）作为合适的溶剂和LiTFSI锂盐混合，以制备用于安全LIBs的具有高离子电导率的电解质。各种表征和测试表明，高度灵活的醚基可显著降低粘度并为锂离子提供配位位点，而DMC可降低粘度并有效提高锂离子传输速率和迁移数。该电解质在Li/LiFeO电池中于室温以及60℃的高温下均表现出优异的电化学性能。更重要的是，随着DMC的加入，基于离子液体的电解质保持不可燃，且适量的DMC可有效抑制锂枝晶的生长。我们目前的工作可能为锂和锂离子电池的高性能和安全性提供一种有吸引力且有前景的策略。
