Spontaneously formed interfacial structure boosting dendrite-free Li metal batteries

Herein a spontaneously formed solid electrolyte interface (SEI) layer with modified spherical structure is prepared by a simple strategy. Caprolactone (CL) is in-situ polymerized to polycaprolactone (PCL) after being triggered by Li metal, and turned into spherical distribution at the surface of Li after recrystallization treatment. Spontaneously formed spherical structure restrains the growth of Li dendrites and boosts homogeneous Li deposition. The Li||Li symmetrical cells present stable plating/stripping behavior at current density of 0.5 to 1.0 mA cm(-2) and exhibit excellent cycling stability. This work provides inspiration for restraining the growth of Li dendrites and building stable electrolyte/metal anode interfaces.