Synthesis and electrochemical properties of lithium methacrylate-based self-doped gel polymer electrolytes

• Published in: Electrochimica acta Vol. 54; no. 19; pp. 4540 - 4544
• Main Authors: Kang, Wan-Chul, Park, Hyoun-Gyu, Kim, Kyung-Chan, Ryu, Sang-Woog
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 30.07.2009; Elsevier
• Subjects: BF3–LiMA; Carbonates; Cations; Chemistry; Electrochemistry; Electrolytes; Ethylene; Exact sciences and technology; Gel polymer electrolyte; General and physical chemistry; Ion disassociation; Ionic conductivity; Lithium; Polymerization; Properties of electrolytes: conductivity; Self-doped; Voltammetry; Self-doped; Ion disassociation; Gel polymer electrolyte; BF3–LiMA; Ionic conductivity; Fourier transformation; Organic carbonate; Electrical properties; Polymer solid electrolyte; Doped materials; BF3-LiMA; lon disassociation; Infrared spectrometry; Lithium Compounds; Electrochemical properties; Crosslinked polymer; Methacrylate salt polymer; Chemical synthesis
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2009.03.050

In this study, a strategy for synthesizing lithium methacrylate (LiMA)-based self-doped gel polymer electrolytes was described and the electrochemical properties were investigated by impedance spectroscopy and linear sweep voltammetry. LiMA was found to dissolve in ethylene carbonate (EC)/diethyl carbonate (DEC) (3/7, v/v) solvent after complexing with boron trifluoride (BF 3). This was achieved by lowering the ionic interactions between the methacrylic anion and lithium cation. As a result, gel polymer electrolytes consisting of BF 3–LiMA complexes and poly(ethylene glycol) diacrylate were successfully synthesized by radical polymerization in an EC/DEC liquid electrolyte. The FT-IR and AC impedance measurements revealed that the incorporation of BF 3 into the gel polymer electrolytes increases the solubility of LiMA and the ionic conductivity by enhancing the ion disassociations. Despite the self-doped nature of the LiMA salt, an ionic conductivity value of 3.0 × 10 −5 S cm −1 was achieved at 25 °C in the gel polymer electrolyte with 49 wt% of polymer content. Furthermore, linear sweep voltammetry measurements showed that the electrochemical stability of the gel polymer electrolyte was around 5.0 V at 25 °C.