Lithium nitrate (LiNO3) in the solvent N,N-dimethyl acetamide (DMA) was regarded as a base,by adding thereto solvent dimethyl sulfoxide (DMSO),chemical and physical properties of complexing solvent,charging profile and reaction mechanism were investigated.Electrolyte with DMSO added in LiNO3-DMA is capable of forming a protective solid-electrolyte interphase (SEI) on Li anode,which effectively enhances the chemical compatibility and reduces the polarization resistance of LiNO3-DMA so that the charging profile has been improved.The Li-air cell stably cycled 40 times with capacity limited to 1 000 mAh/gcarbon at current density of 0.2 mA/cm2.SEM and XRD identified the discharge products of both LiNO3-DMA and LiNO3-DMA/DMSO are Li2O2,but hydrophobic methacrylic in DMSO inhibits formation of by-product LiOH.In addition,during LiNO3-DMA cycling S-containing compound can be generated which contributes much to discharge termination.%以硝酸锂-二甲基乙酰胺(LiNO3-DMA)有机电解液体系为基础,向电解液体系添加溶剂二甲基亚砜(DMSO),研究分析了混合溶剂电解液的物化性质、恒流充放电及反应机理.DMSO的添加可以使锂负极形成稳定的固体电解质相界面(SEI)膜,有效增强了LiNO3-DMA与锂的化学兼容性,降低了极化阻抗,因此循环性能有所提高.截止比容量为1 000 mAh/gcarbon、电流密度为0.2 mA/cm2时可稳定循环40周.SEM及XRD分析表明,LiNO3-DMA和LiNO3-DMA/DMSO放电均生成可循环产物Li2O2,但DMSO中的疏水性甲基抑制了LiNO3-DMA中副产物LiOH的生成.此外,LiNO3-DMA循环过程中生成了含硫化合物,这是导致放电终止的重要原因.
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