A Modular Solid-State Electrolyte Platform Based on a Charged Double Helical Polymer

Our group has been developing a class of rigid solid electrolytes based on a highly charged double helical polyanion self-assembled with ion-containing fluids. We term this class of materials <i>molecular ionic composites</i> (MICs). These materials are highly thermally stable, and can reach ~ 1 GPa tensile modulus and &gt; 1 mS/cm ionic conductivity with only 10-20% polymer content, and even with a substantial loading of cations like Li⁺ or Na⁺. Although MICs are macroscopically solid, the nanoconfined and partially ordered ions inside move only modestly slower (ca. a factor of 3) than in the neat precursor fluid. We can modulate the mechanical, transport, and chemical/thermal stability properties of MICs over wide ranges by changing the content and molecular weight of the polymer, and the chemistry of the ions and other mobile components. I will discuss the state of understanding of MICs, from the dependence of multi-scale morphology and transport on composition and liquid crystallinity, to the influence of specific molecular interactions on properties. I will discuss progress toward practical alkali-metal batteries, as well as extensions beyond our original MIC materials that include (1) segregation of highly Li-conductive nanocrystalline phases, and (2) high modulus thermo-reversible hydrogels.