Micha Philip Fertig is a PhD student in the Department of Stationary Energy Storage at the IKTS site in Hermsdorf. In his doctoral thesis, he is working on sustainable battery concepts.

I am doing my doctorate in the Department of Stationary Energy Storage – for which the Friedrich Schiller University Jena provides me with a state graduate scholarship. In the group, we are working on cell concepts to store excess energy electrochemically. As part of my dissertation, I am working on sodium-based battery cells. I present my research at scientific conferences and in peer-reviewed articles. I also supervise other students in their theses. In addition, I am project manager of a publicly funded research effort to transfer a novel cell concept from research to application.

For your PhD, you are working on the topic of medium-temperature solid-state batteries based on sodium-beta alumina – how did that come about?

I studied electrochemistry at the Friedrich Schiller University Jena and attended a lecture by Prof. Michael Stelter on novel cell concepts during my master studies. He mentioned the possibility of writing the final thesis close to the application at Fraunhofer IKTS. So I came to the institute for my master thesis and subsequently decided to do my PhD here as well.

In my PhD, I am doing research on sodium-based solid-state batteries. These are batteries that use a solid-state electrolyte, which has many advantages. In the cell system I am researching, the aim is to combine the advantages of high-temperature cells, which are being developed here at the institute, with the advantages of conventional ion cells. An ion-conducting solid electrolyte perfected at IKTS is used, which has excellent mechanical, chemical and electrochemical properties. However, in the new cell concept, solutions must be found to suitably connect the interfaces of the individual cell components – this is what I am working on in my doctoral thesis.

What do you find so appealing about this topic?  

Batteries have come into even greater focus as a result of the energy and mobility transition, and it is no longer possible to imagine our everyday lives without them. Sodium-based batteries are promising here because sodium not only ensures high specific energy in the cell but is also found around a thousand times more frequently in the earth's crust than lithium. We can therefore demonstrate an environmentally friendly alternative throughout the entire life cycle of the battery.

What is particularly exciting about my topic is that it is not enough to develop individual components that function well; they must also be able to develop their performance in interaction. From a technical point of view, it is particularly interesting that battery research is highly interdisciplinary and that you therefore come across numerous interesting personalities and topics and always learn something new. Indeed, battery research brings together people from physics, chemistry, electrical engineering and materials science. But chemical engineering and process engineering are also important factors in the development of the cell, the battery and the module.

"Joseph Fraunhofer stood out not only because he was an outstanding researcher, but also because he managed to bring his developments into application and then market them. In my opinion, this concept is still super relevant 200 years later."

What do you think are the advantages of obtaining a doctorate at Fraunhofer?

Joseph Fraunhofer stood out not only because he was an outstanding researcher, but also because he managed to bring his developments into application and then market them. In my opinion, this concept is still super relevant 200 years later. It is exciting here at Fraunhofer to experience this closeness to application and industry and to have the chance to actually be able to transfer the research into application. I find the work here at Fraunhofer IKTS very motivating and enriching, and it is simply fun. We are a young team with experts in different fields. The working atmosphere is very pleasant, and you can realize your ideas and receive the support you need.

The short-term plan is, of course, to successfully complete my dissertation here at IKTS. In the future, I would then like to move to industry to contribute the experience I have gained here at the institute and to further deepen my knowledge.