Discipline: Chemistry and Chemical Sciences
Subcategory: Materials Science
Eden Rivers - University of Washington
Co-Author(s): Greg Newbloom and Lilo Pozzo, University of Washington, Seattle, WA
Renewable energy harvesting technologies such as wind and solar cannot provide on-demand sources of power unless they are paired with energy storage technologies (e.g., batteries). Flow batteries are the best candidate for grid-scale load shifting, bridging and power management due to their safety, efficiency and scalability. Flow batteries operate by pumping liquid-based electrolytes into a two part cell where charging/discharging occurs through ion exchange across a membrane. Unfortunately, the current membrane technology (Nafion©, a Chemours fluoro-polymer) is expensive to synthesize and cannot be optimized to improve performance. This poster will highlight the development of a new, low-cost membrane based on ceramic materials. This work investigates variations in ceramic membrane structure and properties that arise from the curing of sodium silicate in different acid solutions. Ideally, ceramic membranes for flow batteries should have pore sizes of 0.5 – 2 nm to selectively transport protons but not other electrolyte molecules. Pore size, shape and network structure were characterized through fitting of small angle x-ray scattering (SAXS) profiles. Macroscopic membrane features such as defects were studied using scanning electron microscopy (SEM). Key membrane performance attributes (i.e., proton conductivity and vanadium ion permeability) were also determined and are presented. Acid chemistry was found to have an effect on pore size, shape and network structure. Furthermore, pores were the ideal size for flow battery membranes. However, this structural information could not be directly correlated to key flow battery performance attributes. SEM investigations indicate that membranes contain inherent stress fractures leading to macroscopic defects. These defects likely dominate the observed performance attributes. Future investigations should focus on developing new methods to eliminate these defects and create uniform structures.
Funder Acknowledgement(s): The Clean Energy Institute; The University of Washington.
Faculty Advisor: Lilo Pozzo, firstname.lastname@example.org
Role: I created each of the samples and tested them in each of our experiments, then analyzed the data to determine their characteristics. I created the poster, including most of the figures and drawings used. I had great help and advice from my mentor and PI for every step of the way, but all the work was done by me.