Electrophoretically deposited polymer-in-ceramic electrolyte comprising polymerized ionic liquid

Abstract

Composite solid electrolytes, in which superionic ceramics materials are combined with ion-conducting polymers, could revolutionize electrochemical-energy-storage devices enabling higher energy density, providing greater stability during operation and enhanced safety. However, the interfacial resistance between the ceramic and polymer phases strongly suppresses the ionic conductivity and presents the main obstacle for the practical uses.

In the current article, an attempt has been made to improve composite conductivity by significantly increasing ceramic concentration in combination with the polymerized ionic liquid (PolyIL). The film was prepared by the electrophoretic deposition method. We believe this is the first demonstration of a PolyIL as a multifunctional additive in EPD, enabling both field-driven deposition and an integrated electrolyte architecture that ensures mechanical cohesion and continuous ion transport pathways. We deposited thirty-micron-thick composite film, which contains more than 90 wt% of LAGP. It has porous structure, in which single ceramic particles and their aggregates are coated by PolyIL. Broad Band Dielectric Spectroscopy method is used for the understanding of ion transport in composite polymer-in-ceramic electrolyte. We observed no improvement in conductivity and assign this to the dominating effect of interfacial energy barriers limiting Li transport in composites.