金属锂电极表面预处理液的优化选择

The optimum option for surface pretreatment of lithium electrode

为了提高二次金属锂电极的性能,采用1,3-二氧戊环、1,4-二氧六环和四氢呋喃作为预处理液,对锂电极进行浸泡处理,而后与LiCoO2组装成扣式电池,并测试其性能.结果表明:用1,3-二氧戊环和1,4-二氧六环处理可使锂电极循环性能及放电性能得到较大提高,在四氢呋喃中处理却使电极性能下降.相比而言,1,4-二氧六环处理后电池性能更好,但其50次循环后放电特性不佳.通过配方改进研究发现,采用1,4-二氧六环(质量分数70%)、电解液(质量分数30%)、LiPF6饱和溶液作预处理液可使锂电极性能大幅提高,不但循环寿命增加约20%,第80次循环的放电平台也增加了近200 mV.

The lithium metal electrode was pretreated to be soaked in 1,3-dioxolane,1,4-dioxane and tetrahydrofuran separately,then Li metal cell was assembled with LiCoO2cathode.It is found that the cycling and discharge performance are improved greatly when lithium electrode was pretreated with 1,3-dioxolane and 1,4-dioxane.But lithium electrode properties treated with tetrahydrofuran can＇t be improved.Comparatively,the cell has better performance when treated with 1,4-dioxane,but its discharge property was depressed after 50 cycles.Further measurements show that the performance of lithium electrode can be improved greatly if it is pretreated in the following project： 1,4-dioxane（70%）＋electrolyte（30%）＋LiPF6（saturated concentration）.The cycling life increases about 20%,and the discharge plateau at 80th cycle increases about 200 mV.