LiPF_6/三氟乙酰胺室温熔盐的制备及在碳-碳电容器中的性能

利用LiPF6和三氟乙酰胺为前驱物,制备了低共熔温度约为-62℃的室温熔盐,并测试了该熔盐作为碳-碳电化学电容器(EDLCs)电解液时的性能。其中,使用差示扫描量热法(DSC)和红外光谱法(FTIR)分析了不同LiPF6和三氟乙酰胺配比熔盐的热稳定性,拟制了该二元组分的共熔相图,认为LiPF6和三氟乙酰胺极性基团间的氢键作用促成了室温熔盐的形成。循环伏安(CV)、交流阻抗(EIS)和电导等测定结果表明,所制备的LiPF6/三氟乙酰胺电解液的室温电导率为1.30mS/cm,电化学窗口大于5.6V,大于60℃的使用温度,作为电解液可满足碳-碳EDLCs的使用要求。

Preparation and Performances of Room Molten Salt as Electrolyte in Carbon-carbon Capacitor Based on LiPF6 and 2Trifluoroacetamide

A novel room molten salt with an eutectic temperature of about-62 ℃ is prepared using LiPF6 and 2trifluoroacetamide as precursors.And then its performances are evaluated in carbon-carbon elec-trochemical double layer capacitor(EDLC) as electrolyte.The thermal properties of the complex electrolyte with different molar ratios are characterized and then the liquid-solid phase diagram is presented by using differential scanning calorimeter(DSC) and Fourier transform infrared spectroscopy(FTIR).The hydrogen bonding interaction between LiPF6 and 2trifluoroacetamide molecules is attributed to the formation of the as-prepared molten salt.In addition,the results of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS) and conductance tests show that the as-prepared LiPF6/2trifluoroacetamide electrolyte has a maximum conductance at room temperature,i.e.1.30 mS/cm,a stable electrochemical window of ~ca.5.6 V,an applicable temperature of more than 60 ℃,suggesting it is a promising electrolyte candidate for carbon-carbon EDLCs.