In situ synthesis of graphitic C3N4–poly(1,3-dioxolane) composite interlayers for stable lithium metal anodes

Abstract

Lithium metal anodes (LMAs) possess the largest energy density among all anode candidates, while dendrite growth is a huge barrier in the direct application of LMAs in batteries. Herein, an ultrathin graphitic C₃N₄–poly(1,3-dioxolane) (CN–PDOL) composite interlayer was in situ synthesized by cationic ring-opening polymerization upon lithium metal anodes. Flexible PDOL could isolate electrolytes, remitting the corrosion reactions and consumption of electrolytes, while g-C₃N₄ nanoflakes could reduce the crystallinity of PDOL, increase ion-conductivity and uniform Li-ion fluxes. At a current density of 3 mA cm⁻², the synergistic effect of CN and PDOL could enable 850 h stable Li plating/stripping behavior at an overpotential of 70 mV. In this work, a facile and accessible design of a composite buffer layer was developed for lithium metal anodes, which might be of interest to a broad community investigating surface modifications.