Glyoxylic-Acetal-Based Gel-Polymer Electrolytes for Lithium-Ion Batteries

This work focuses on the combination of two strategies to improve the safety of lithium-ion batteries: The use of a glyoxylic-acetal, 1,1,2,2-tetraethoxyethane, in the solvent blend to reduce the flammability of the liquid electrolyte and further its confinement inside of a methacrylate-based polymer matrix, to prevent electrolyte leakage from the battery cells. Physicochemical characterizations of this novel gel-polymer electrolyte (GPE) confirm its improved thermal properties and suitable ionic conductivity, as well as electrochemical stability window. Tests in LFP and hard carbon half-cells vs. lithium metal show that the combination of glyoxylic-acetal-based electrolyte and the methacrylate-based polymer matrix can promote lithium-ion intercalation and deintercalation with stable capacity values. The application in lithium-ion battery full cells furthermore shows that the GPE can promote a similar performance compared to the respective liquid electrolyte and can therefore make possible the realization of energy storage devices with improved safety characteristics.