A novel all-solid electrolyte based on a co-polymer of poly-(methoxy/hexadecal-poly(ethylene glycol) methacrylate) for lithium-ion cell

A novel graft copolymer solid electrolyte with a relatively high ionic conductivity, 10^−3.9 S cm⁻¹ at 30 °C and 10^−3.1 S cm⁻¹ at 80 °C, is prepared by free radical polymerization in this study. The polymer consists of methacrylate as the backbone and a mixture of hexadecal (C₁₆)–methoxyl terminated oligo(ethylene oxide) at a certain ratio as side chains. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analysis reveal that non-polar unit (C₁₆) end-modification not only greatly increases the mobility of the ethylene oxide (EO) chains, but also suppresses their local crystallization behavior by interrupting the regular arrangement, therefore improving the conductivity of the obtained electrolyte.