A Systematic Study of Vinyl Ether-Based Poly(Ethylene\nOxide) Side-Chain Polymer Electrolytes

Herein, we report\non the synthesis of a systematic library of vinyl\nether-based poly­(ethylene oxide) (PEO) side-chain copolymers in order\nto reduce the crystallization of PEO. The influence of different grafted\nPEO side chain lengths, the grafting density, and the [Li+]:[EO] ratio after mixing with LiTFSI on the glass transition\ntemperature (Tg), the crystallinity,\nand the resulting ionic conductivity was examined. Copolymers bearing\nlonger PEO side chains and higher grafting densities show higher crystallization\ntendencies while their Tg is reduced at\nthe same time. Furthermore, the addition of LiTFSI reduces crystallization\nbut increases Tg. Because these effects\nare directly impacting the ionic conductivity, we demonstrate that\nthe different parameters need to be carefully adjusted in order to\nbalance their influence. In this way, a fundamental view that shows\nthe potential of PEO side-chain copolymers for their applications\nas polymer electrolytes is provided.