(549d) Hybrid Solid-Liquid Lithium Ion Electrolytes: Effect of Porosity and Swelling on the Ionic and Molecular Mobility

Lithium ions batteries (LIB) are the most prominent technology in the field of energy storage where liquid electrolytes are the most commonly used solution in the battery industries. Despite their attractive properties (such as high ionic conductivity and thermal stability at the ambient/sub ambient conditions), they have shown safety concerns due to their flammability which has led to the development of new electrolytes systems. Hybrid solid-liquid electrolytes like the heterogeneous structural battery electrolyte (SBE) where two discrete co-existing phases are formed: one thermoset structural phase providing mechanical integrity and one percolating liquid ion-conducting phase. The phase separation is possible as a result of the variations in the solubility parameters of the monomers with respect to those of the formed polymers. The main feature of the polymer network is the microporous structure that gives structural integrity to the system thanks to the polymeric solid phase and, at the same time, conducts the ions through the percolating liquid phase. Although the SBE has shown remarkable properties results when tested in a negative half-cell lamina, it is not fully understood how the morphology and chemical composition affect the molecular transport in the system.

The present work describes an attempt to investigate ions transport in a series of hybrid solid-liquid electrolytes with different liquid contents using NMR-techniques. It is clearly shown that not only the tortuosity but also the ions conductance through the polymer phase plays a critical role in determining the electrochemical performances of these electrolytes.