In situ formed cross-linked polymer networks as dual-functional layers for high-stable lithium metal batteries

Lithium-metal anodes (LMAs) have been recognized as the ultimate anodes for next-generation batteries with high energy density, but stringent assembly-environment conditions derived from the poor moisture stability dramatically hinder the transformation of LMAs from laboratory to industry. Herein, an in situ formed cross-linked polymer layer on LMAs is designed and constructed by a facile thiol-acrylate click chemistry reaction between poly(ethylene glycol) diacrylate (PEGDA) and the crosslinker containing multi thiol groups under UV irradiation. Owing to the hydrophobic nature of the layer, the treated LMAs demonstrate remarkable humid stability for more than 3 h in ambient air (70% relative humidity). The coating humid-resistant protective layer also possesses a dual-functional characterization as solid polymer electrolytes by introducing lithium bis(trifluoromethanesulfonyl)imide in the system in advance. The intimate contact between the polymer layer and LMAs reduces interfacial resistance in the assembled Li/LiFePO4 or Li/LiNi0.8Co0.1Mn0.1O2 full cell effectively, and endows the cell with an outstanding cycle performance.