(Nanowerk News) Batteries are indispensable in the global effort to reduce the use of fossil fuels. However, challenges remain: their production requires a lot of energy, the materials used are scarce, and batteries are difficult to recycle. Therefore, several research groups at the Austrian Institute of Science and Technology (ISTA) are working on new batteries that are more environmentally friendly and more efficient.
From cell phones to laptops to electric vehicles and beyond, lithium-ion (Li-ion) batteries are essential in many people’s daily lives. What may seem lucrative, however, leads to many problems: The metals used in battery cells—especially cobalt and lithium—are available in only a few places. As a result, ecosystems are destroyed, people are toiling under extremely harsh working conditions, and industries are dependent on fragile supply chains, where sudden layoffs can have drastic consequences.
Research groups in chemistry and physics at the Austrian Institute of Science and Technology (ISTA) are trying to tackle this problem. All of their projects share the same goal: Find new materials to make batteries more sustainable.
Recycle through living nature
2021 marks the first year that Li-ion battery prices have increased. “The reason is the scarcity of cobalt and lithium in combination with skyrocketing demand, which is essential for Li-ion batteries in their current form,” said Stefan Freunberger, Assistant Professor at ISTA. The good news: You can substitute cobalt — just what Freunberger wants to do. His research group is focused on building batteries with the performance of Li-ion batteries, but only from very abundant elements. Specifically, they use organic materials consisting only of elements such as carbon, hydrogen, and oxygen, which come—as the name suggests—from organic sources. The research group is also investigating the direct use of inorganic elements such as sulfur.
In addition, unlike cobalt-based materials, this material has the potential to be fully recycled by living things and the overall energy for battery production can be reduced. “Normally, manufacturing Li-ion batteries consumes a lot of energy and has a lot of CO2 footprint. Using the right materials, you can reduce these values by an order of magnitude,” says Freunberger. “If everything goes well, we will have a functional battery with organic elements in the next few years. We are not yet ready for commercialization, but our results are promising,” concluded Freunberger. Researchers are supported in their ambitious project by ERC Proof of Concept Grants, which help evaluate the commercial potential of research results.
Magnesium: A beacon of hope
One of the materials that can be mined in an environmentally friendly way is magnesium. In addition, it is one of the ten most common elements in the earth’s crust. This shiny silver light metal is the focus of “MAGNIFICO”. Researchers from the Austrian Institute of Technology (AIT) and ISTA joined forces for this project funded by the Austrian Research Promotion Agency (FFG). Together, they attempted to use magnesium for the battery anode instead of lithium. But while magnesium generally has proper electrochemical properties, a magnesium anode is incompatible with most electrolytes—the medium that allows current to flow in a battery.
In particular, the electrolyte decomposes in the presence of magnesium, thereby limiting the electrical conductivity. To solve this critical problem, the project team worked to create anode shields that prevent electrolyte decomposition. For her role in this ambitious project, ISTA Assistant Professor Bingqing Cheng and her research group provided computational calculations and machine learning to better understand and predict material properties.
Industrial battery reimagined
While Li-ion batteries are largely installed in the countless electrical appliances in our daily lives, Professor Verbund Maria Ibáñez’s research group at ISTA thinks bigger. “Industrial companies have the highest demand for energy”, explains Mario Palacios Corella, postdoctoral fellow in the Ibáñez group. “Our goal is to empower them with a new, more sustainable redox flow battery technology.”
Conventional redox flow batteries contain an ion-selective membrane known as Nafion. These highly durable chemicals are not only expensive, but also have serious negative environmental impacts. The new battery that researchers in Klosterneuburg are working on in the EU-funded “MeBattery” project does not require this separator membrane at all. To this end, the group experimented with various chemical substances and their ability to mix and form electroactive materials.
“In a redox flow battery, chemical species that are prone to gaining or losing electrons are dissolved in an electrolyte and stored in two different tanks,” continues Corella. When energy is needed, the electrolyte is pumped into the reaction chamber, where the two electrolytes are separated by a membrane that allows the flow of ions but not dissolved chemical species. Spontaneous electrochemical reactions that occur on both sides of the membrane give rise to a flow of electrons, thus producing a current. “By exploiting the physical properties of electrolytes and playing around with their inadequacies, we can get rid of membranes. This is a breakthrough,” added the young chemist.
From abundant elements as substitutes for rare metals to completely new materials—with their innovative approach, scientists at ISTA are working on the foundation of a more environmentally friendly and sustainable energy system.