The energy transition starts with materials

– If a battery works, it is because the right materials have been combined in the right components. Whether you want to optimise ionic conductivity or thermal stability, it comes down to the choice of materials.

Anna Martinelli is Professor at the Department of Chemistry and Chemical Engineering at Chalmers and Deputy Director of the Swedish Electricity Storage and Balancing Centre, SESBC.

Her research moves between fundamental materials science and technologies for the energy transition. It also spans several scientific methods and disciplines – something that has become increasingly common in materials research.

Where a scientific paper could once be based on results from a single method, research today often requires several methods and expertise from different disciplines. It is the way we do research today, she says – but it also comes with a risk:

– Working with an increasing number of methods gives research greater breadth, but at the same time there is a risk of losing deep expertise in each individual method.

For Anna Martinelli, it is not a question of choosing one or the other.

– I think we need both breadth and depth in the research we do.

From materials to energy

Energy was not the obvious destination when Anna Martinelli began her research career.

Her master’s thesis focused on materials related to biology and health. When she later applied for PhD positions, several different paths were open to her. At Chalmers, the project was about materials for fuel cells.
– It sounded technical, but also really exciting. I wanted to work on something tangible. I was happy for it to involve more materials and less theory, so to speak.

Along the way, chemistry also entered the picture.
– My projects involved collaboration with colleagues in chemistry. So even then, I started working across disciplinary boundaries. But energy was never something I had set out to work with. I more or less ended up there by chance.

Today, the link between materials science and energy is central to her research. Anna Martinelli looks at a fuel cell or electrolyser in terms of the materials and components it is made of. But making an individual material work is not enough.

– There is also a systems perspective, of course. A catalyst or an ion conducting liquid has to perform in its device, but that device in turn has to function efficiently in a larger system, for example in connection to the electricity grid.

Ionic liquids open up new possibilities

Fuel cells and electrolysers are only one part of Anna Martinelli’s research. One recurring area is that of ionic liquids – salts that melt at relatively low temperatures and whose properties can be tailored through their chemical composition.

Ionic liquids can offer high ionic conductivity and thermal stability, negligible volatility and low flammability. These properties make them interesting as electrolytes in batteries, fuel cells and other energy storage systems.

Ionic liquids are also studied in separation and recycling processes. They can, for example, be used to extract lithium, cobalt, nickel and rare earth elements from used batteries and end-of-life magnets. Other potential applications include polymer recycling and recovering valuable substances from biomass.

In June 2027, researchers from around the world will gather at Chalmers for the ILMAT-9 conference. Taking that as a starting point, where does research on ionic liquids and ionic-liquid-based materials stand today, and which questions are particularly interesting right now?

– That is a difficult question! Research on ionic liquids is a large field, both in Europe and around the world. I collaborate with many colleagues, for example in Spain, the UK, France, the US and Australia.

Ionic liquids have their origins in research on molten salts, but the field gained considerable momentum in the early 2000s. Since then, the focus has shifted – from synthesising ionic liquids that are stable in the presence of moisture and air to understanding their nanostructure and their potential use in applications such as batteries and supercapacitors.

How the properties of ionic liquids change in nanopores has also been a major research topic. Today, researchers are studying areas including their electrochemical stability and different types of hydrogen bonding, as well as their potential as greener and efficient solvents. 

When materials meet industry

At the Swedish Electricity Storage and Balancing Centre, SESBC, the connection to application becomes clearer. The centre’s vision is an electricity system that can enable a society based on 100 % renewable energy. As a larger share of electricity comes from sources such as solar and wind, there is a growing need to store energy and balance production and consumption as electricity supply varies.

Research within SESBC therefore spans the entire chain – from materials and components to energy systems and intelligent energy management. Anna Martinelli’s research is close to the materials and components end of that chain.

In one of the projects, her group works on materials and components for PEM fuel cells and electrolysers. PEM stands for proton exchange membrane.

– It is about what happens at the materials and component level. What do we need to develop and improve to increase efficiency?

The starting point can be very concrete.
– If something is not working, where do the losses come from? What needs to be improved to increase efficiency?

SESBC brings together both academic and non-academic partners, including small companies and start-ups developing their own components.
– We want to work with their products and see how we can help develop them.

Anna Martinelli also collaborates with companies outside SESBC. One example is the Gothenburg based company PowerCell, where researchers have studied materials and components in operating fuel cells and what happens to them when they are used at high current densities.

– The end user wants to know how a fuel cell should be operated. How should the materials and components be prepared to make it perform as well as possible?

An electrolyser – for the rest of us

Electrolysers and fuel cells sit on opposite sides of the same chemical process.
Anna Martinelli explains:
– An electrolyser is a device that splits water into hydrogen and oxygen. The reaction is not spontaneous, so you have to put electricity in.

A fuel cell essentially does the reverse.
– It consumes hydrogen and oxygen and generates electricity instead. So that is how the two are connected. One generates the fuel that we may later use in a fuel cell, and the fuel cell generates electricity.

When electricity is plentiful, an electrolyser can use it to produce hydrogen.
– Then you have stored energy separately, which you can use later when there is a shortage of electricity.
This is one example of how the research moves between scales – from what happens inside a material to how the technology functions as part of a larger energy system.

Three projects led to Chalmers

Anna Martinelli’s path to Chalmers began much earlier – and largely by chance.
She grew up outside Rome with a Swedish mother and an Italian father. She had already started university in Italy when, at the age of 20, she set off on an Interrail trip with a cousin.
During the journey, she planned to decide whether to continue her studies in Italy or try life in Sweden.
– I thought that if I got away from everything familiar, it would be easier to think freely and work out what I really wanted. What does my gut tell me?

She ended her journey in Sweden.
– I had almost nothing with me. A backpack, a few clothes in rather awful colour combinations, boots and very little money.

She ended up at Växjö University, now Linnaeus University, where she continued her studies with a specialisation in physics.
– I started working part-time as a teaching assistant in mathematics on the foundation year quite early on. I was only one to three years older than my students!

When the time came to do her master’s thesis, she wanted to experience a different research environment.
– I thought I might do my thesis somewhere else. I wanted to try working in a larger research environment.

She looked up professors and emailed them.
– I found three master’s thesis projects. One for me and two for my friends.
She laughs when she looks back on it.
– I didn’t think much of it at the time. But looking back now, I think: that was actually quite proactive!

The three moved to Gothenburg and carried out the experimental work for their master’s theses at Chalmers. It was the beginning of something much longer.

From research assistant to professor

After her master’s thesis, Anna Martinelli had the opportunity to pursue a PhD in Lund, Karlstad or at Chalmers. The decision was not the result of any long-term career plan.

– It was quite pragmatic. I suppose I thought Gothenburg sounded like a more fun city. So, I chose Gothenburg and Chalmers.

After completing her PhD and spending three years abroad, including as a postdoctoral researcher at LEPMI in Grenoble, she became one of the young researchers recruited in 2010 in an early round of Chalmers’ initiative for assistant professors.
Unlike the previous academic system, the initiative offered young researchers a clearer path towards establishing their own research activities and progressing in their academic careers.
– I was selected through an international recruitment process. There was a plan for those of us who were young researchers at the time. For example, we received start-up funding to build our own groups and a leadership programme that was very much appreciated.

Anna Martinelli became a docent in 2015, an associate professor in 2020 and a full professor in 2025.

A research thread that goes back years

Her research received early recognition in 2013, when Anna Martinelli was awarded funding from the King Carl XVI Gustaf 50th Anniversary Fund for Science, Technology and Environment for research on electrolytes for the next generation of fuel cells.

But what she also remembers from the day she was due to receive the award at the Royal Palace is something entirely different.
– It was so exciting and stressful that I left my digital camera in the taxi, which disappeared like a flash.
She managed to get it back – only to discover that photography was strictly prohibited anyway.
– So, I had rushed around and stressed myself out for nothing.

The world comes to Chalmers

From 21 to 24 June 2027, Chalmers will host ILMAT-9 – Ionic Liquid Derived Materials. Anna Martinelli is the conference coordinator, bringing together researchers working on ionic liquids and ionic liquid-based materials.

It will be the first time the conference series has been held in the Nordic region. Researchers from across Europe, as well as countries including the US, Brazil and Australia, are expected to come to Gothenburg.

The topic also reflects the breadth of the research field in which Anna Martinelli works. Ionic liquids are studied for energy storage, but also for applications including the recovery of critical metals and other circular materials processes.

And one more thing, Anna …

… is still waiting for an invitation to the Nobel Prize banquet. So, if anyone happens to have an invitation and can bring a friend …

And when she is not doing research, she plays tennis. The dream of a future tennis career is still alive.