Dissertation defence (Materials Engineering): MSc Mahdi Moghaddam


15.12.2023 at 14.00 - 18.00
MSc Mahdi Moghaddam defends the dissertation in Materials Engineering titled “Scanning Electrochemical Microscopy Characterization of Energy Materials” at the University of Turku on 15 December 2023 at 14.00 (University of Turku, Publicum, Pub2 lecture hall, Turku).

Opponent: Dr. Dmitry Momotenko (Carl von Ossietzky University of Oldenburg, Germany)
Custos: Professor Pekka Peljo (University of Turku)

Doctoral Dissertation at UTUPub:

The audience can participate in the defence by remote access: https://echo360.org.uk/section/7acf57da-0345-4aa2-99df-af01ce002817/public


Summary of the Doctoral Dissertation:

Envision a future energy sources are environmentally friendly. Thats the goal – to upgrade energy systems, making them better for the planet. This dissertation takes a closer look at the intricate details of how we can achieve this by understanding the inner workings of materials used for energy.

Think of these materials as the key players in the world of clean energy. I utilized an advanced tool called scanning electrochemical microscopy (SECM) to examine two main groups of these materials. Firstly, I focused on materials used in fuel cells – miniature power plants fueled by oxygen and hydrogen. Our research revealed that when specific materials are combined, like Nafion and carbon black, they confine oxygen in the Nafion parts. This previously hidden oxygen could cause errors in calculating the efficiency of fuel cells. Now, we can take it into account.

Moving on, I explored effective energy storage in Redox Flow batteries. Imagine having small energy boosters inside batteries – these are what we call solid boosters. What we discovered is that for these boosters to perform well, they need sufficient surface area for optimized electrochemical reactions. Its similar to having a larger kitchen counter – more space means better efficiency.

In a captivating experiment, we focused on micrometer-scale solid booster particles. Using SECM and optical microscopy in a novel approach, we positioned a micrometer electrode (smaller than a single human hair) behind the particle and utilized its surface as a reflective mirror to see through the particle while illuminating it with light. We discovered that these particles undergo a fascinating transformation over time, providing insights into how the porosity of the particle can impact charge storage.
Ultimately, this research not only advances our understanding of the intricate processes within energy materials but also paves the way for more efficient and sustainable energy solutions. By shedding light on previously overlooked factors, such as confined oxygen in fuel cells and the behavior of micrometer-scale solid boosters, we are better equipped to shape a cleaner and more sustainable energy future.
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