Ionic Permeability within Thermally-Activated Batteries
In this work, we performed a series of fundamental studies to probe the ionic mobility and conductivity of the electrolyte. First, by utilizing a series of single cells frozen at various activated times, we performed electron probe microanalysis (EPMA) on the cell cross-sections to quantify the transport of bromine tracers. Through the use of image analysis techniques, we mapped out of the concentration of bromine throughout each cell and elucidated the complex process of electrolyte diffusion and flow. Next, using a custom-built pressure vessel cell, we quantified the permeability of the electrolyte through the oxide binder during and after activation. Furthermore, we investigated the effects of compaction pressure on both the permeability and internal impedance of the separator. Collectively, these experimental studies provide quantitative transport information about the electrolyte, which can be used to inform predictive models for battery activation and improve the understanding of the impact of separator compaction on electrolyte transport properties.
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.