利用共溶剂1,5-戊二醇（PD）和聚乙二醇（PEG）改进13 m（m=[mol盐]/[kg溶剂]质量摩尔浓度）LiOAc作为水系锂离子电池电解液的电化学稳定窗口,研制低成本无氟水系混合溶剂醋酸锂电解液。通过红外吸收和拉曼散射光谱对电解液中水分子的活性进行表征,结果表明,在混合溶剂电解液中水分子的活性受到抑制。电化学测试表明电解液成分为2 m LiOAc-PD0.5PEG0.5时,具有最宽的电化学稳定窗口3.10 V,使Li4Ti5O12负极可进行可逆充放电,最后Li4Ti5O12//LiMn2O4全电池测试得到初始平台电压为2.3 V,能量密度为0.0616 kWh/kg,相较于13 m LiOAc电解液具有更高的比容量和循环稳定性。
Abstract
Using 1,5-pentanediol （PD） and polyethylene glycol （PEG） as co-solvent to improve the electrochemical performance of 13 m （m=[mol salt]/[kg solvent]） LiOAc as aqueous lithium-ion batteries electrolytes obtains low-cost fluorine-free aqueous mixed solvent lithium acetate electrolytes. The activity of water molecules in the electrolyte was characterized by infrared absorption and Roman scattering spectroscopy. The results show that in the mixed solvent electrolytes the activity of water molecules is inhibited. Electrochemical tests show that the electrolytes have the widest electrochemical stability window of 3.10 V when the electrolyte composition is 2 m LiOAc-PD0.5PEG0.5, which makes the negative electrode Li4Ti5O12 reversibly charge and discharge. Li4Ti5O12//LiMn2O4 full cell with 2 m LiOAc-PD0.5PEG0.5 tests show an initial platform voltage of 2.3 V and specific energy of 0.0616 kWh/kg, which obtains higher capacity and cycle stability than 13 m LiOAc electrolytes.
关键词
锂离子电池 /
电解液 /
储能 /
溶剂化作用
Key words
lithium-ion batteries /
electrolyte /
energy storage /
solvation
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参考文献
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基金
内蒙古自治区科技计划项目（2020GG0151）; 广东省高水平创新研究院项目（2021B0909050001）
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