Comparative Study of M[N(SO2F)(SO2CF3)]-[N-Butyl-N-methylpyrroridinium][N(SO2F)(SO2CF3)] (M = Li, Na, K, Rb, Cs) Ionic Liquid Electrolytes
Comparative Study of M[N(SO2F)(SO2CF3)]-[N-Butyl-N-methylpyrroridinium][N(SO2F)(SO2CF3)] (M = Li, Na, K, Rb, Cs) Ionic Liquid Electrolytes
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M[N(SO2F)(SO2CF3)]-[N-丁基-N-甲基吡咯啶鎓][N(SO2F)(SO2CF3)](M=Li、Na、K、Rb、Cs)离子液体电解质的比较研究
DOI：
10.1021/acs.jpcb.0c06578
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Toshiyuki Nohira
中科院分区：
文献类型：
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作者：
Takayuki Yamamoto;Shu Nishijima;Toshiyuki Nohira
系统评价了一系列M[FTA]-[C4 C1 pyrr][FTA]离子液体（M =碱金属，FTA =（氟磺酰基）（三氟甲基磺酰基）酰胺，C4 C1 pyrr = N-丁基-N-甲基吡咯烷）作为碱金属离子电池电解质的理化性质.首先，测量在x（M[FTA]）= 0.20（x（M[FTA]）= M[FTA]的摩尔分数）下的M[FTA]-[C4 C1 pyrr][FTA] IL的粘度（η）、离子电导率（σ）和密度（ρ）。在298 K时，σ值为1-3 mS cm-1，其增加顺序为：Na < Li < K < Rb < Cs，表明Li基离子液体不符合碱金属离子电荷密度预测的趋势。第二，在使用η、σ和ρ测量结果获得的瓦尔登图中，Li基IL显示出比其他FTA基IL略低的垂直截距值。第三，通过循环伏安法研究了离子液体的电化学稳定性，并测定了碱金属的氧化还原电位（E（M+/M））。FTA基离子液体的E（M+/M）值按Cs < Rb < K < Li < Na的顺序增加。随后，我们将所获得的E（M+/M）值与其他一般电解质（如碳酸丙烯酯（PC）基电解质和水溶液）的E（M+/M）值进行了比较。FTA基离子液体的E（M+/M）值的趋势与PC基电解质的E（M+/M）值的趋势相似，并且与水溶液的E（M +/M）值的趋势显著不同。特别是FTA-和FSA-基离子液体（FSA =双（氟磺酰基）酰胺）在各种电解质中呈现最负的E（Na+/Na）和E（K+/K）值，这表明利用这些离子液体电解质开发Na-和K-离子电池将呈现显著的优势。
We systematically evaluated the physicochemical properties of a series of M[FTA]–[C4C1pyrr][FTA] ionic liquids (ILs) (M = alkali metal, FTA = (fluorosulfonyl)(trifluoromethylsulfonyl)amide, C4C1pyrr =N-butyl-N-methylpyrrolidinium) as electrolytes for alkali metal-ion batteries. First, the viscosity (η), ionic conductivity (σ), and density (ρ) of the M[FTA]–[C4C1pyrr][FTA] ILs atx(M[FTA]) = 0.20 (x(M[FTA]) = molar fraction of M[FTA]) were measured. The σ values ranged from 1–3 mS cm–1at 298 K and increased as follows: Na < Li < K < Rb < Cs, which indicated that the Li-based IL did not obey the trend predicted by the charge densities of alkali metal cations. Second, the Li-based IL exhibited slightly lower vertical intercept values than the other FTA-based ILs in the Walden plots obtained using the results of η, σ, and ρ measurements. Third, the electrochemical stability of the ILs was investigated by cyclic voltammetry, and the redox potentials of the alkali metals (E(M+/M)) were determined. TheE(M+/M) values of the FTA-based ILs increased as follows: Cs < Rb < K < Li < Na. Subsequently, we compared the obtainedE(M+/M) values with those of other general electrolytes, such as propylene carbonate (PC)-based electrolytes and aqueous solutions. The trend inE(M+/M) values of the FTA-based ILs was similar to that of PC-based electrolytes and was significantly different from that of aqueous solutions. In particular, the FTA- and FSA-based ILs (FSA = bis(fluorosulfonyl)amide) presented the most negativeE(Na+/Na) andE(K+/K) values among various electrolytes, which indicated that utilization of these IL electrolytes for the development of Na- and K-ion batteries would present significant advantages.