Self-healing single-ion-conductive artificial polymeric solid electrolyte interphases for stable lithium metal anodes

Unstable solid-electrolyte interphase (SEI) layer, accompanied with detrimental Li dendrite growth, is the major challenge for realizing viable Li metal batteries. Herein, we report a self-healing and single-ion conductive artificial SEI (SS-ASEI) layer to stabilize Li metal anode, suppress the Li dendrite growth and promote the Li plating/stripping kinetics. The polymeric SS-ASEI layer is optimized to be dynamically cross-linked poly(dimethylsiloxane) filled with 7 wt% SiO2 nanoparticles. The modified Li symmetric cell achieves extremely stable plating/stripping cycling for 1340 h at 0.5 mA cm−2 and 1.0 mAh cm−2 cutting-off capacity. Superior rate capability and cycling stability of the modified anode are also demonstrated in cells with commercial NCM811 (LiNi0.8Co0.1Mn0.1O2) cathode. The self-healing ability, elastic deformation capability, selectively high Li-ion conductivity and low liquid electrolyte swelling rate of our SS-ASEI layer synergistically account for the superior performances of modified Li electrode over the bare Li electrode.