液体电解液改性石榴石型固体电解质与锂负极的界面

The liquid electrolyte modified interface between garnet-type solid-state electrolyte and lithium anode

石榴石固体电解质型的固态锂金属电池因具有高能量密度、高安全性和长循环寿命等优点而受到了研究人员的重点关注,然而石榴石型电解质和锂负极之间存在巨大的界面阻抗,严重阻碍了电池的正常工作。针对该问题,本文主要在石榴石型固体电解质与锂负极之间的界面引入少量的电解液,减少石榴石型电解质与锂负极的界面阻抗,使得固态对称锂电池正常循环。进一步地采用扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线光电子能谱(XPS)和电化学阻抗谱(EIS)研究了石榴石型电解质与锂负极之间界面层的形貌、成分、界面阻抗和循环稳定性。研究结果表明,液体电解液极大地降低了石榴型电解质与锂负极间的界面阻抗,在80℃情况下,石榴型电解质与锂负极循环前的面电阻为1.89Ω·cm^(2),循环后的面电阻为3.24Ω·cm^(2)。

Garnet-type electrolyte-based solid-state lithium metal batteries have attracted the attention of researchers due to their advantages of high energy density,high safety and long cycle life.However,there is huge interfacial impedance between garnet-type electrolyte and lithium anode,which seriously impedes the normal operation of the cell.To solve this problem,a bit of liquid electrolyte is introduced into the interface between garnet-type electrolyte and lithium anode in this work,which obviously reduces the interfacial resistance,and makes the solid-state lithium symmetric cells cycle normally.Furthermore,the morphology composition,interfacial resistance and cycle stability of the interface layer between garnet-type electrolyte and lithium anode are studied by scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS)and electrochemical impedance spectroscopy(EIS).The research results show that liquid electrolyte greatly decreases the interface resistance,especially at 80℃,the values are as low as 1.89Ω·cm^(2) and 3.24Ω·cm^(2) before and after cycling,respectively.