A new binary electrolyte containing tetramethylene sulfone (TMS) and hexamethylene diisocyanate (HDI) with lithium difluoro(oxalate)borate (LiODFB) as the lithium salt has been prepared and investigated for physicochemical properties. A linear relationship between the frontier molecular orbital energies and the oxidation/reduction potentials is preliminarily confirmed. Compared to the pure TMS electrolyte, a mixture of TMS and HDI exhibits a wider electrochemical stability window, better wettability and an improved low temperature performance. Combined with the mixed electrolyte, LiCoO2 and LiNi_(1/3)Mn_(1/3)Co_(1/3)O2 cathode materials show specific capacities of nearly 134.5 mA h g~(-1) and 168.3 mA h g~(-1) after 50 cycles, respectively, which is superior to those containing the traditional electrolyte. Furthermore, the composite electrolyte exhibits a good compatibility with the high voltage LiNio.5Mn1.5O4 cathode material which has a specific capacity close to 120 mA h g~(-1) after 50 cycles. The enhanced battery performance is mainly due to HDI, which has a high oxidation potential (5.2 V), good wettability, a low melting point and an outstanding ability to form effective solid electrolyte interface layers. In addition, LiODFB makes a contribution to the compatibility of the electrolyte due to its passivation toward aluminum, its high solubility and its ability to support reversible metallic lithium cycling. All of the properties above indicate that the LiODFB/HDI/TMS mixed electrolyte is a promising material and can have applications in the field of lithium batteries.
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机译：制备了一种新的含有四亚甲基砜（TMS）和六亚甲基二异氰酸酯（HDI）以及二氟（草酸）硼酸锂（LiODFB）作为锂盐的二元电解质，并对其理化性质进行了研究。初步确认了前沿分子轨道能量与氧化/还原电势之间的线性关系。与纯TMS电解质相比，TMS和HDI的混合物具有更宽的电化学稳定性窗口，更好的润湿性和改善的低温性能。与混合电解液结合使用，LiCoO2和LiNi_（1/3）Mn_（1/3）Co_（1/3）O2正极材料显示的比容量接近134.5 mA hg〜（-1）和168.3 mA hg〜（-1 ）分别经过50次循环，优于含传统电解液的循环。此外，该复合电解质与高压LiN0.5Mn1.5O4正极材料表现出良好的相容性，该正极材料在50次循环后的比容量接近120mA h g·（-1）。增强的电池性能主要归因于HDI，它具有高氧化电位（5.2 V），良好的润湿性，低熔点和出色的形成有效固体电解质界面层的能力。另外，LiODFB由于其对铝的钝化，高溶解度以及支持可逆金属锂循环的能力，对电解质的相容性做出了贡献。上述所有性质表明，LiODFB / HDI / TMS混合电解质是一种有前途的材料，可以在锂电池领域中应用。
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