Operando Visualization of Utilization within Functioning Battery Electrodes

Abstract

Adoption of thick electrode configurations can increase the overall systems level energy density of future batteries by minimizing inactive components such as metal foils and separator layers. However, simply increasing the activematerial in the electrode does not translate to full utilization and delivery of a stable capacity over extended cycling. Thus, it is necessary to have understanding of electron transfer and ion transport, ideally with spatial and temporal resolution, to enable the rational design of larger scale systems with high energy density. A specific benefit of energy dispersive x-ray diffraction in conjunction with a synchrotron light source is the ability to measure intact stainless steel housing electrochemical cells, preventing any artifacts due to the use of cell windows, removal of the electrodes, or any post-treatment methods used in the cell disassembly process. Further, the ability to collect x-ray data real time concurrently with the electrochemical activity provides insight into the kinetics of the electrochemistry under usage conditions. The application of this technique to determine phase localization and rationalize electrode utilization will be highlighted in this presentation.