Lithium-Ion Battery Electrolyte Containing Fluorinated Solvent and Additive

With the development of large mobile equipments (such as electric vehicles), energy storage power stations and the other portable charging devices, lithium-ion battery is gradually occupying the dominant position of the chemical power market. Electrolyte is one of the most important components of lithium-ion battery, having a significant impact on many properties of lithium-ion battery, such as the output voltage, energy density, power density, longevity, temperature range, safety performance and so on. In general, owing to the very high electronegativity and low polarizability of fluorine, fluorinated organic solvent shows very different physical properties compared to the common organic solvent. Specifically, fluorinated solvent has a low melting point, high flash point, high oxidation decomposition voltage, and good wettability with the electrode material. Therefore, fluorinated solvent has a potential application in the research and development for high voltage electrolyte, high security electrolyte, wide temperature window liquid electrolyte, and the other special functional electrolyte. Here, the recent research and applications on fluorinated solvents and additives in lithium-ion battery electrolyte are reviewed. The mechanisms for the enhancement performance of lithium-ion battery electrolyte with the use of fluorinated solvents and additives are also analyzed and discussed in detail. Simultaneously, the fabrication methods of fluorinated solvents such as fluorinated ethylene carbonate (FEC) are summarized. Finally, the research prospects and problems for fluorinated solvents and additives in lithium-ion battery electrolyte are also discussed in detail.