Rohan Suri1,Samuel Chen2,Kriste An3,Haoyan Fang4,Md Farabi Rahman4,Miriam Rafailovich4
Ladue Horton Watkins High School1,Ed W. Clark High School2,Harvard-Westlake School3,Stony Brook University, The State University of New York4
Rohan Suri1,Samuel Chen2,Kriste An3,Haoyan Fang4,Md Farabi Rahman4,Miriam Rafailovich4
Ladue Horton Watkins High School1,Ed W. Clark High School2,Harvard-Westlake School3,Stony Brook University, The State University of New York4
In response to the global challenge to find a clean and sustainable power source, scientists have turned their attention to anion exchange membrane fuel cells (AEMFCs). Though significant progress has been made in the development of AEMFCs, several obstacles impede their application<sup>1</sup>. Poor water management in AEMFCs, for example, leads to anode flooding and cathode dehydration, causing cell deterioration to occur over time. Additionally, platinum will ionize and migrate during operation, causing the AEM to degrade, leading to eventual cell failure<sup>2</sup>. Left unmitigated, these problems could easily render a possible solution to the energy crisis useless. Herein, we report that depositing ZnO thin films on an AEM using Atomic Layer Deposition (ALD) can lead to increased maximum power outputs for AEMFC's. For testing, ALD was used to deposit 5, 10, 15, 20, and 30 layers of ZnO onto anion exchange membranes (Sustainion grade T). Atomic Force Microscopy (AFM) was used to verify that a uniform layer formed a flat tomography, proving that ZnO was successfully coated on the surface. Our results demonstrated that there appears to be an optimal thickness of the ZnO thin film layer, with 10 cycles yielding the highest observed maximum power density of 0.430 W/cm<sup>2</sup> (a 28.7% increase from the control cell). Further addition of ZnO began to reduce maximum power densities, with 30 layers of ZnO causing a maximum power density of 0.274 W/cm<sup>2</sup> (an 18.0% decrease). Afterward, XRD measurements were performed, demonstrating the amorphous nature of the ZnO deposited, giving further insights into how the nanostructure could affect possible results. A possible explanation for our observations could be that ZnO improves the electrochemical durability of the AEM, allowing it to function for longer periods of time and become more resistant to the osmotic gradient created within the cell during operation. Future research should include further spectroscopic and microscopic characterization of the membrane and electrodes before and after the performance tests to gain a deeper understanding of our results. Regardless, the scientific community must continue to work with ZnO as a possible solution to many of the problems that plague AEMFC's, furthering humanity's goal to find sustainable energy sources.<br/><br/>Support from the Office of Naval Research [N00014-29-1-2858] is gratefully acknowledged.<br/><br/><sup>1</sup> Felseghi, Raluca-Andreea, et al. "Hydrogen fuel cell technology for the sustainable future of stationary applications." <i>Energies</i> 12.23 (2019): 4593.<br/><sup>2 </sup>Raut, Aniket Madhukar, et al. "Migration and Precipitation of Platinum in Anion Exchange Membrane Fuel Cells." <i>Angewandte Chemie International Edition (2023):</i> e202306754.