Effects of Molecular Architecture on the Simultaneous Enhancement in Modulus and Ionic Conductivity in Polymer Solid Electrolytes*

In an effort to develop solid polymer electrolytes (SPEs) with enhanced mechanical modulus and ionic-conductivity, we utilize PMMA stars with high functionality as rigid nanoparticle additives to a liquid PEO electrolyte, doped with LiTFSI. The resulting SPEs exhibit two orders of magnitude higher conductivity and one order of magnitude higher mechanical strength compared to their linear PMMA blend analogues. In addition, the former remain solid- like over an extended temperature range. This performance is due to the SPE morphology of dispersed PMMA nanoparticles within the liquid electrolyte host, which allows for the formation of a highly interconnected network of pure liquid electrolyte that leads to high ionic conductivity (comparable to that of the neat PEO electrolyte).