October: Tristan Petit (HZB)

Tristan Petit leads the Young Investigator Group Nanoscale Solid-Liquid Interfaces at the Helmholtz Zentrum Berlin. He is at the HZB since over 10 years. He started with a Postdoctoral Fellowship from the Alexander von Humboldt Foundation in 2013, became a leader of a junior research group in 2015 after receiving a Freigeist Fellowship from the VW Foundation and then leader of a young investigator group in 2021 supported by an ERC Starting Grant. We had the chance to talk to Tristan Petit about his work and motivation.

Interview

What are you currently working on?

Tristan Petit: My team is investigating fundamental electrochemical processes at solid-liquid interfaces, using X-ray and optical spectroscopy techniques. I am currently exploring new way to store energy in a relatively new class of layered 2D materials called MXenes, which is funded by my ERC Starting Grant NANOMXM. These materials are hydrophilic, very conductive and have an electrochemically active surface. This gives them the ability to intercalate protons and ions between their layers very fast while also exchanging electrons with the intercalated species in a process that is called pseudocapacitance. However, a molecular understanding of the pseudocapacitive charging mechanism in such materials is still missing. We therefore use different kind of techniques, such as soft X-ray microscopy at the synchrotron BESSY II or infrared spectroscopy in our lab, to characterize these processes during electrochemical cycling.

What is your personal motivation?

Tristan Petit: I am excited by the idea of contributing to the discovery of the next generation of electrochemical energy storage system, that may change the way we see electrified mobility. I like the scientific challenge of solving complex problems but would also like to have an impact on our daily life. For example, I am using an electric cargo bike since several years by now and while I enjoy it, I often experience that there is still room for improvement. Imagine that you could charge your cargo bike is a few seconds, have enough power to transport two kids plus groceries without having to sweat and still have enough range for a day of commuting. If that would exist, I am pretty sure that we would see less cars in the streets!

What kind of challenges are you facing in the near future?

Tristan Petit: While developing new technologies, it is important to keep in mind that they must be safe and sustainable on the long term and still be efficient enough to remain competitive to current solutions. One of the major problems of MXenes today is the high energy cost and the use of toxic chemicals for their synthesis. We will start very soon to synthesize these materials in a completely different route, that do not have these drawbacks while still being highly scalable. We will have to carefully consider the quality and the stability of this new generation of MXenes for our applications.

If you could make a wish for something for your research, what would you wish for?

Tristan Petit: I have the chance to see our research progress daily thanks to the help of excellent PhD students and postdocs, who are the ones at the front-line doing experiments and bringing fresh ideas to the field. They are the most vital source for high quality research. I wish I could continue to be supported by bright and motivated early career scientists in the years to come!

Where do you see your discipline in 5-10 years?

Tristan Petit: Looking back at how fast the field of MXene developed over the last 10 years (the first MXene was reported in 2011), I am convinced that it is very hard to predict what is to come. However, I believe that one of the major advantages of these 2D materials that has still to be fully exploited is their easy processability in the form of inks. The combination of MXenes with other materials into novel architectures of 3D-printed batteries will probably be a very active field of research in a few years.

ORCID: 0000-0002-6504-072X