Solving the cost-efficiency compromise
Marco Cecchetti
- Thesis title: Experimental and model-based study of cross-over phenomena aimed at the development of an innovative selective layer for Vanadium Redox Flow Battery
- PhD Tesi Supervisors: Matteo Zago
- Phd: STEN, 34° cycle (starting year 2018)
- B. Sc: 2015, Energy Engineering, Politecnico di Milano
- M. Sc: 2018, Energy Production (Power Production), Politecnico di Milano
Tell us something to introduce yourself
Hi! I’m Marco Cecchetti and I’m from Muggiò, near Monza. At the time of this interview, I am a PhD candidate of the MRT Fuel Cell & Battery Lab and I am currently writing my PhD thesis. In our research group I’m the guy who makes bad puns, but excellent funny photomontages. What I enjoy most from the everyday life as a doctorate researcher is discovering and learning new things.
Tell us about your research.
My PhD project regards the design and development of the “Barrier”, an innovative selective layer for Vanadium Redox Flow Batteries (VRFB). The Barrier enhances the selectivity of membranes for VRFB, allowing the use of thinner membranes, reducing the cost of the technology, hence improving the competitiveness. Indeed, despite several advantages for stationary energy storage, some technological issues limit the competitiveness of VRFB. One of these issues is cross-over, i.e. the undesired permeation of vanadium ions through the membrane, that leads to battery self-discharge and capacity loss. To mitigate this phenomenon, battery manufactures are forced to employ thick membranes, which are expensive (up to 50% of the battery stack cost) and limit battery efficiency due to large ohmic losses. Therefore, in the design of a VRFB there is a trade-off between efficiency, costs and capacity loss.
After studying cross-over phenomena by developing an experimental methodology and a physical-based model for improving the comprehension of the physics, the Barrier layer was designed and developed. The Barrier proved to be able to reduce cross-over fluxes by over 66% and the capacity loss by 80%, improving the selectivity and the columbic efficiency of thin and cheap membranes with low ohmic losses, enabling their use in VRFB application and thus solving the compromise between efficiency and costs.
After studying cross-over phenomena by developing an experimental methodology and a physical-based model for improving the comprehension of the physics, the Barrier layer was designed and developed. The Barrier proved to be able to reduce cross-over fluxes by over 66% and the capacity loss by 80%, improving the selectivity and the columbic efficiency of thin and cheap membranes with low ohmic losses, enabling their use in VRFB application and thus solving the compromise between efficiency and costs.
What aspect of your work is most exciting you right now?
The most exciting aspect of my work is the possibility to work on the different scales of the technology. Indeed, during my project I was able to work not only on the battery testing at lab-scale, but also on the materials and their characterization, always having in mind the requirements of a commercial-scale system.
What’s the most significant outcome of your research?
The ability of the Barrier to improve the selectivity of the membrane: a reduction of cross-over fluxes over 66% was obtained with the Barrier without hindering battery efficiency. The Barrier on a very thin membrane deeply reduces by 80% the capacity loss of a VRFB, improving its coulombic efficiency. Moreover, the results of my work are competitive with the best alternatives found in literature. This is a very outstanding result because it enables the use of thin and cheap membranes that can cut stack costs by 30%. Finally, another very important result is having proved that the Barrier can be manufactured with a commercially available technique.
Why did you choose to start this experience and why did you choose PoliMi?
I want to give my contribution for a more sustainable world. Doing research and innovation in the energy sector allows me to achieve this goal by working on innovative solutions for energy conversion and storage and by pushing the boundaries of knowledge.
I’ve chosen Polimi for the quality of the formation it offers for PhDs. Moreover, research groups of Polimi are deeply involved in exciting projects with industrial and academic partners, therefore Polimi offers to its doctorate researches several opportunities for networking and working with the best experts in their sectors. Personally, I was able to work with industries leader in the energy storage sector and to collaborate with both Italian and foreign researchers.
How would you describe this period of your life with three adjectives?
The first adjective that comes to my mind for describing these years is challenging: in a PhD project you are creating something new or studying phenomena still debated in literature. You’re basically adventuring into the unknown. Therefore, to overcome the challenges that arises during your work you develop a set of hard and soft skills. This leads to the second adjective: formative. The last adjective is resilient. In this job before getting an up, you go through a lot of downs. Thus, you cannot let yourself be discouraged from a failed experiment or an unexpected result. Instead, on the contrary, you must embrace any failure and learn from it.
What are your plans after the end of the PhD?
First of all, a vacation. After that, I am open to any opportunity, but my goal is to pursue an academic career.
Which advice would you give to new engineers that are pondering about PhD in Polimi?
The first advice I’d give is the same as many other my colleagues: don’t be scared by misbeliefs and misconceptions about PhD. Many people consider PhD as a waste of time and PhD graduates as overqualified for jobs outside the academia world. This is not true: in the always evolving energy sector, industries crave the skills obtained in a PhD.
My second advice is for graduating students: if you are considering doing a PhD, look for a thesis in a research group to have a taste of how the research world works and to understand if you are suited for it (or if it is suited for you).
My second advice is for graduating students: if you are considering doing a PhD, look for a thesis in a research group to have a taste of how the research world works and to understand if you are suited for it (or if it is suited for you).
If you could choose anyone in the world of any time as a mentor, who would you pick?
I would like to pick Albert Barillé as a mentor. He is the author of the “Once Upon a Time…” franchise, which includes “Once Upon a Time…Life” (Esplorando il Corpo Umano in Italy) and “Once Upon a Time…The Discoverers” (Invenzioni e Inventori). His works inspired millions of kids around the world to learn more about scientific stuff…and I was one of them. Another mentor I would pick is Mehdi Sadaghdar, an electrical engineering whose experiments inspired thousands of people around the world into the engineering world.
