Preparation of Lithium‐Ion Conducting Organic–Inorganic Polymer Hybrids via Reversible Addition‐Fragmentation Chain Transfer Polymerization and Sol–Gel Reaction

ABSTRACT This study focuses on the preparation of hybrid polymer electrolyte films containing metal ions via a non‐aqueous sol–gel reaction of a vinyl polymer with terminal phosphonic acid moieties and metal alkoxides. Poly(poly[ethylene glycol]methyl ether methacrylate‐ co ‐4‐vinylphenylboronic acid 1,3‐propanediol ester) (poly(PEGMA‐ co ‐VPBP)) with a weight‐average molar mass of 5800 and a dispersity of 1.19 was synthesized by reversible addition‐fragmentation chain transfer polymerization using 2,2′‐azobis(isobutyronitrile) and S,S′ ‐bis(2‐ethylphosphonic acid)trithiocarbonate. MOP hybrid electrolyte films (M = metal or metalloid) containing Ti, B, Al, and Nb atoms were prepared using poly(PEGMA‐ co ‐VPBP), metal alkoxides or boron alkoxide, and lithium perchlorate. The ionic conductivities are in the order of NbOP > AlOP > BOP > TiOP at 20°C, and the NbOP hybrid electrolyte film shows an especially high ionic conductivity of 4.9 × 10 −4 mS/cm at 20°C. BOP hybrid electrolyte shows the highest conductivity of 3.0 × 10 −2 mS/cm at 40°C and the highest activation energy from the Arrhenius plots.