锂金属阳极表面SEI膜的制备与研究

Preparation and study of SEI film on surface of lithium metal anode

采用将锂金属阳极浸润在氟化铜混合溶液的方法对锂阳极表面进行SEI层的人工修饰。系统观察不同浓度氟化溶液和浸润时间对阳极表面生成SEI膜的影响,选择1.0%质量分数CuF_(2)溶液浸润10 s为最佳实验条件。结合电化学测试与形貌表征研究锂金属电池循环时间、阳极界面上锂的沉积情况和SEI层的力学性能,结果表明,人工SEI层在不同电流密度下将锂电池循环时间提高了160%~446%,促进锂在界面层均匀沉积且显著抑制锂枝晶的生长。研究结果对锂金属电池通过表面修饰实现长循环、高倍率充放电研究具有一定的指导意义。

The surface of lithium anode was artificially modified with SEI layer by wetting lithium metal anode in copper fluoride mixture.The effect of different concentration of fluorination solution and infiltration time on the formation of SEI film on the anode surface was systematically observed.The optimal experimental condition was selected for 10 s infiltration with 1.0%CuF_(2) concentration.The cycle time of lithium metal batteries,the deposition of lithium on the anode interface and the mechanical properties of SEI layer were studied by electrochemical testing and morphological characterization.The results show that the artificial SEI layer increases the cycle time of lithium batteries by 160%to 446%under different current densities,promotes the uniform deposition of lithium on the interface layer and significantly inhibits the growth of lithium dendrites.The research results have certain guiding significance for the study of long cycle and high rate charge and discharge of lithium metal batteries by surface modification.