Effect of Pore Topology on Ionic Conductivity in Hybrid Electrolytes

To simultaneously achieve high ionic conductivity and mechanical stiffness, we pursue a hybrid organic-inorganic nanocomposite materials design for developing solid-state electrolytes (SSE). We first create a continuous silica network via sol-gel synthesis to provide a mechanically rigid backbone. During subsequent fluid exchange, the polymer is grafted onto the backbone through reactive groups and anchored into structure to establish the ion conducting phase. This approach allows to decouple the mechanical from the ionic transport properties and augment both simultaneously. The network of the gel-cast material is further conditioned by influencing structural evolution during drying. Changing sample aspect ratio introduces various degrees of anisotropy and spatial gradients in the network topology, as revealed by nano-mechanical characterization using Brillouin light scattering, as well as ion mobility. The strong correlation between the adiabatic elastic modulus and the activation energy of ion hopping has led to developing an improved transition state theory model for this process, which we use to develop materials design strategies for harnessing this structural conditioning and create better performing SSE.