PIM-1 as an artificial solid electrolyte interphase for stable lithium metal anode in high-performance batteries

• 来源期刊: 能源化学
• 年，卷（期）: 2020,（3）
• 页码范围: 83-90
• 页数: 8页
• 语种: 英文

摘要

Lithium metal anode is a promising electrode with high theoretical specific capacity and low electrode potential.However,its unstable interface and low Coulombic efficiency,resulting from the dendritic growth of lithium,limits its commercial application.PIM-1 (PIM:polymer of intrinsic microporosity),which is a polymer with abundant micropores,exhibits high rigidity and flexibility with contorted spirocenters in the backbone,and is an ideal candidate for artificial solid electrolyte interphases (SEI).In this work,a PIM-1 membrane was synthesized and fabricated as a protective membrane on the surface of an electrode to facilitate the uniform flux of Li ions and act as a stable interface for the lithium plating/stripping process.Nodule-like lithium with rounded edges was observed under the PIM-1 membrane.The Li@PIM-1 electrode delivered a high average Coulombic efficiency (99.7％),excellent cyclability (80％ capacity retention rate after 600 cycles at 1 C),and superior rate capability (125.3 mAh g-1 at 10 C).Electrochemical impedance spectrum (EIS) showed that the PIM-1 membrane could lower the diffusion rate of Li+ significantly and change the rate-determining step from charge transfer to Li+ diffusion.Thus,the PIM-1 membrane is proven to act as an artificial SEI to facilitate uniform and stable deposition of lithium,in favor of obtaining a compact and dense Li-plating pattern.This work extends the application of PIMs in the field of lithium batteries and provides ideas for the construction of artificial SEI.