Abstract
Organic-inorganic hybrid materials are explored for application as solid electrolytes for lithium-ion batteries. The material consists of a porous silica network, of which the pores are infiltrated by poly(ethylene oxide) and lithium perchlorate. The synthesis involves two steps: First the inorganic backbone is created by acid-catalyzed sol-gel synthesis of tetraethyl orthosilicate to ensure continuity of the backbone in three dimensions. In the second step, the polymer and salt are imbued into the porous backbone via solvent exchange. During drying, the cylindrical disk-shaped specimens shrink mainly in radial direction, which results in spatially non-uniform structural developments. While this inhomogeneity is not discernable in the material’s chemical compositional or thermal properties, it is manifest in its ionic conductivity and adiabatic elastic modulus. The ionic conductivity in the center of the specimens is projected to be between one and two orders of magnitude higher than the measured average across the sample diameter. The process that yields a structure with enhanced ionic mobility during post synthesis physical conditioning is inferred from careful analysis and numerical interpretation of measurable quantities, and the implications for the design of nano-structured hybrid electrolytes with high ionic conductivity are discussed.
This is a project carried out by Vazrik Keshishian to determine whether the Li+ conductivity in his hybrid silica-PEO materials depends on the distance from the sample center. The results of this project have been published on December 28, 2024 in the Journal of Chemical Physics (volume 161, page 244505). The abridged identifier for this project is ‘inhomo’lytes.’
Inhomo'lytes Collaborators