Polyethers with phosphate pendant groups by monomer activated anionic ring opening polymerization: Syntheses, characterization and their lithium-ion conductivities

This paper describes the preparations and lithium-ion conductivities of various solid polymer electrolytes for potential use in high-energy density lithium-ion batteries. The ring opening polymerization of epoxides (M1--M6), catalyzed by Zn(II), Cu(II) and Cd(II) complexes in the presence of tetrabutylammonium bromide (TBAB), yielded polyethers (P1-P6) in which phosphates were attached as pendant groups. A reaction condition where Zn(II) catalyst used slightly excess to TBAB increased the polymerization rate remarkably and yielded the polyethers with higher molar masses in a short time. These polymerizations proceeded following a "monomer activated anionic ring opening polymerization" mechanism. These living like polymerizations also progressed according to "formation of polymer chain per initiator" model. The solid-state lithium-ion conductivities of these polymers were examined using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The conductivity of one of the solid polymer electrolytes with 40 wt% of LiTFSI was 5.2 x 10 super(-5) S cm super(-1) at room temperature and 2.9 x 10 super(-4) S cm super(-1) at 80 [degrees]C.