Wu Feng, Zhu Qizhen, Chen Renjie, Chen Nan, Chen Yan, Li Li
Beijing Key Laboratory of Environmental Science and Engineering , School of Materials Science and Engineering , Beijing Institute of Technology , Beijing , 100081 , China . Email:
Collaborative Innovation Center of Electric Vehicles in Beijing , Beijing , 100081 , China.
Chem Sci. 2015 Dec 1;6(12):7274-7283. doi: 10.1039/c5sc02761f. Epub 2015 Sep 18.
Lithium-ion batteries have been attracting much attention which enables the revolution of wireless global communication. Ionic liquids are regarded as promising candidates for lithium-ion battery electrolytes because they can overcome the limitations of high operating temperatures and flammability concerns of traditional electrolytes. However, at low temperatures they suffer from low ionic conductivity and phase transition. In this paper mixed electrolyte systems are described based on -methoxyethyl--methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide (PyrTFSI) and lithium difluoro(oxalate)borate (LiODFB) lithium salt, with ethylene sulphite (ES) or dimethyl sulphite (DMS) as a cosolvent. The mixed electrolyte system exhibits good ion transport properties (a conductivity of 8.163 mS cm), a wide electrochemical window (5.2 V), non-flammability, the ability to form films to protect the anode and a large operating temperature range (-40 °C to 60 °C). We compare the performance and function of the new mixed electrolyte system with a variety of ionic liquid/cosolvent electrolyte systems developed in previous studies. The ring-chain synergy takes advantage of the availability of both high permittivities based on the ring-like components and low viscosities based on the chain-like components in the mixed electrolyte system and causes the electrolyte to exhibit a good overall performance in safety, ion transport and compatibility with electrodes.
锂离子电池备受关注，它推动了无线全球通信的变革。离子液体被视为锂离子电池电解质的有前途的候选者，因为它们可以克服传统电解质工作温度高和易燃性方面的局限性。然而，在低温下，它们存在离子电导率低和相变的问题。本文描述了基于甲氧基乙基甲基吡咯烷双（三氟甲磺酰）亚胺（PyrTFSI）和二氟（草酸）硼酸锂（LiODFB）锂盐，以亚硫酸乙烯酯（ES）或亚硫酸二甲酯（DMS）作为共溶剂的混合电解质体系。该混合电解质体系表现出良好的离子传输性能（电导率为8.163 mS/cm）、宽电化学窗口（5.2 V）、不可燃性、形成保护膜保护阳极的能力以及较大的工作温度范围（-40°C至60°C）。我们将这种新型混合电解质体系的性能和功能与先前研究中开发的各种离子液体/共溶剂电解质体系进行了比较。环状-链状协同作用利用了混合电解质体系中基于环状组分的高介电常数和基于链状组分的低粘度的优势，使电解质在安全性、离子传输以及与电极的兼容性方面展现出良好的整体性能。
