A flexible, robust, and high ion-conducting solid electrolyte membranes enabled by interpenetrated network structure for all-solid-state lithium metal battery

Poly(vinyl alcohol)/poly(ethylene glycol) (PVA/PEG) semi-interpenetrating networks (s-IPN) were synthesized for the application of solid electrolyte membranes of lithium metal batteries. Thermal, mechanical and dimensional stability, lithium-ion conductivity, interfacial compatibility, and cell performance were evaluated to assure their application. As this s-IPN structure suppressed the crystallinity by formation of network structure, both the lithium-ion conductivity and mechanical strength were simultaneously enhanced. The PVA/PEG-3s-IPN showed the highest lithium-ion conductivity of 3.26 x 10(-4 )S cm(-1) in a wide electrochemical window (5.8 V vs. Li/Li+), maintaining the robust solid-state with the tensile strength beyond 16.2 MPa at room temperature. The synthesized solid electrolyte membranes exhibited quite high specific capacity over 122 mAh g(-1) at 0.1 C from Li|PVA/PEG-3 s-IPN|LiFePO4 cell and the long-term stable lithium stripping/plating performance for 1000 cycles from Li symmetric cell. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Poly(vinyl alcohol)/poly(ethylene glycol) (PVA/PEG) semi-interpenetrating networks (s-IPN) were synthesized as solid electrolyte membranes for lithium metal batteries. The s-IPN structure suppressed crystallinity, resulting in enhanced lithium-ion conductivity and mechanical strength. The synthesized membranes exhibited high capacity and stable cycling performance.