Exploring electrode/polymer electrolyte interface chemistry and a regulating strategy of interfacial stability: a review

Abstract

Polymer electrolytes have garnered considerable interest as a promising substitute owing to their exceptional mechanical flexibility, and appropriate interfacial compatibility with electrodes. However, the realization of economically viable and industrially scalable solid-state batteries with an elevated energy density and reliable cycling life remains a formidable task. The integration of high-voltage cathodes presents additional challenges, such as polymer electrolyte decomposition, consequential gas discharge, and the formation of an unstable solid–electrolyte interphase (SEI) layer on the lithium metal anode. These issues significantly impact the battery's cycling life and safety, necessitating profound attention towards enhancing the electrochemical stability of polymer electrolytes. Within this comprehensive review, we explore the problems arising from the evolution of the electrolyte/cathode and electrolyte/anode interfaces (e.g., electrochemical decomposition of the electrolyte, reverse cation catalysis, degradation products, etc.), and propose corresponding interfacial remediation strategies (e.g., in situ polymerization, inorganic coatings, etc.). Finally, we describe the persistent challenges and future perspectives aimed at providing strategies for the development of innovative polymer electrolytes capable of realizing high-performance lithium-metal batteries.