A Stable Solid Polymer Electrolyte for Lithium Metal Battery with Electronically Conductive Fillers

Electronic conduction in solid-polymer electrolytes is generally not desired, which causes leakage of electrons or energy loss, and the electronically conductive domains at electrode-electrolyte interfaces can lead to continuous decomposition of electrolytes and shorting issues. However, it is noticed in this work that in an insulating matrix, the conductive domains at certain aspects could also have positive effects on the electrolyte performance with proper control. This work evaluates the limitation and benefits of electronically conductive domains in a solid-polymer electrolyte system and discusses the approach to improve the electrolyte physicochemical properties with densified local electric field distribution, enhanced bulk dielectric property, and charge transfer. By deliberately introducing the conductive domains in a regular solid-polymer electrolyte, stable cycle life, low overpotential, and promising full cell performance could be achieved.