Influence of the cyclic vs. linear carbonate segments in the properties and performance of CO2-sourced polymer electrolytes for lithium batteries

Polycarbonates bearing linear carbonate linkages and polyether segments have demonstrated to be highly attractive solid electrolyte candidates for the design of safe energy storage devices, e.g. lithium metal batteries. In this contribution, we are studying the influence of the introduction of some cyclic carbonate linkages within the polymer backbone on the electrolyte properties. We first describe the synthesis of polycarbonates/polyethers containing different contents of both linear and cyclic carbonate linkages within the chain by the copolymerization of a highly reactive CO2-based monomer (bis(-alkylidene cyclic carbonate)) with poly(ethylene glycol) diol and a dithiol at room temperature. We then explore the influence of the content of the cyclic carbonates and the loading of the polymer by lithium bis(trifluoromethane) sulfonimide (LiTFSI) on the electrolyte properties (glass transition and melting temperatures, ion conductivity and diffusivity). The best electrolyte candidate is characterized by ...