A new polysiloxane based cross-linker for solid polymer electrolyte

• Published in: Journal of power sources 2005-08, Vol.146 (1), p.391-396
• Main Authors: Kang, Yongku, Lee, Junkyoung, Suh, Dong Hack, Lee, Changjin
• Format: Article
• Language: English
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Ionic conductivity; Lithium batteries; Poly(siloxane- g-acrylate) cross-linker; Polymer electrolytes
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2005.03.142

A new cross-linker, poly[siloxane-( g-oligo(ethylene oxide)- co-acrylate)], was synthesized and used to prepare the solid polymer electrolytes (SPE) by in situ thermal curing method with the addition of the ion-conducting plasticizers such as low molecular weight poly(ethylene oxide)dimethyl ether (PEGDME) and poly(siloxane- g-ethylene oxide) (PSi-PEG). Increase of conductivity and decrease of T g were observed as increasing the content of plasticizer. The ionic conductivity was measured to be 7.13 × 10 −4 S cm −1 with 70 wt.% PEGDME and 4.18 × 10 −5 S cm −1 with 70 wt.% of PSi-PEG at 30 °C. The electrochemical stability window of the resulting solid polymer electrolyte could be extended to up to 4.5 V and 5.2 V for PEGDME and PSi-PEG, respectively. Thermal stability of polymer electrolyte was greatly enhanced with siloxane based plasticizer. The degradation of SPE with PSi-PEG started at ca. 350 °C. The SPE plasticized with PSi-PEG, which has good electrochemical stability and thermal stability, could be a promising solid polymer electrolyte for lithium polymer batteries.