Parthasarathi, Senthil-KumarSenthil-KumarParthasarathiChen, HsiHsiChenLiao, Cheng-HungCheng-HungLiaoChang, Shu-JuiShu-JuiChangRangasamy, ManjunathManjunathRangasamyWang, Jui-CheJui-CheWangLin, Yu-HanYu-HanLinWu, Hung-ChunHung-ChunWuWeng, Yu-TingYu-TingWengNAE-LIH WU2025-08-142025-08-142025-11-0103787753https://www.scopus.com/record/display.uri?eid=2-s2.0-105011037656&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/731382Solid polymer membranes/electrolytes (SPEs) can mitigate the threats of commercial lithium-ion batteries (LIBs) that use organic fluid electrolytes. Current SPEs show an inadequate ionic conductivity (at environmental temperature) and exhibit unsatisfactory mechanical strength, restricting their large-scale application. In this study, SPEs are prepared from a solvent-free method and consist of poly(ethylene oxide) (PEO), poly(vinylidene fluoride) (PVDF), lithium bis(trifluoromethane sulfonyl) imide (LiTFSI), and the solid-plasticizer succinonitrile (SN) with superior ionic conductivity, greater durability, and better electrochemical performance. Taguchi composition optimization leads to an optimized film ((PEO)10-LiTFSI)50-SN30-PVdF20, which demonstrates an ionic conductivity (at 303 K) of 1.04 × 10−3 S cm−1, which is two orders superior to bare ((PEO)10-LiTFSI)100 film made without SN. Besides, thanks to PVDF, the optimized ((PEO)10-LiTFSI)50-SN30-PVdF20 membranes exhibit a compressive modulus of 56.8 MPa, which is a five-fold increase when compared to without PVDF-added film (∼10 MPa). The solid-state coin cell is fabricated with LiFePO4/((PEO)10-LiTFSI)50-SN30-PVdF20/Li, exhibits a discharge capacity of 129 mAh g−1, and achieves 84 % capacity maintenance at the end of 300 cycles at 30 °C, indicating the potential of as-prepared SPEs for the posterity of solid-state LIBs, which offer higher energy density and better safety.falseIonic conductivityMechanical stabilityPEOSolid-polymer membranesSuccinonitrile[SDGs]SDG7journal article10.1016/j.jpowsour.2025.2379292-s2.0-105011037656