UV-Curable Solid Polymer Electrolytes Based on Poly(ethylene glycol) and Cardanol Moiety for All-Solid-State Lithium Secondary Batteries

Abstract

Solid polymer electrolytes based on poly(ethylene glycol) and cardanol, a renewable resource from cashew nut shell liquid, were prepared and their properties were investigated. UV-induced self-crosslinkable polymer matrix were synthesized by free radical copolymerization of poly(ethylene glycol) methyl ether methacrylate and 2-hydroxy-3-cardanylpropyl methacrylate. Solid polymer electrolytes were prepared by simple solution casting method followed by UV irradiation, which induces cross-linking reaction of cardanol moieties. The obtained electrolytes were dimensionally stable, free-standing, and thermally stable. Maximum ionic conductivities of 2.6 X 10-5 S/cm at 30 oC and 2.5 X 10-4 S/cm at 60 oC were obtained when cardanol content in the matrix polymer was 8 mol% and lithium salt doping concentration ([Li+]/[EO unit]) was 0.05. The feasibility of the prepared electrolytes to solid polymer electrolytes for lithium secondary batteries was examined by linear sweep voltammetry and galvanostatic charge-discharge cell test. Figure 1