Research in Lower Austria: magnesium for batteries of the future

“We first simulate the movements and positions of all atoms in the material,” explains Bingqing Cheng from the Institute of Science and Technology Austria (ISTA) in Klosterneuburg. “Many material properties and battery performance can be measured with experiments, but you can’t see how the reactions actually take place inside.” “Observations at atomic resolution” require computer simulations and models.

„Machine learning is key
With the traditional quantum mechanical models, such practical tasks would quickly reach their limits. “While solving the Schrödinger equation can predict the properties of any material, including new compounds that have not yet been synthesized,” she explains, “there is a catch: as the number of electrons and atomic nuclei increases, the equation becomes equal to the fastest Supercomputer quickly unsolvable.” Everything that goes beyond a few hundred atomic nuclei or a billionth of a second (nanosecond) is therefore not yet calculable.

In the battery research project “Magnifico”, which Cheng leads together with Martina Romio from the Austrian Institute of Technology (AIT) in Vienna, the quantum mechanical interactions of the individual atoms are to be elucidated using machine learning. “It’s much cheaper than solving the Schrödinger equation, and therefore you can simulate the activities of many more atoms over a much longer period of time,” she says. This is the first time machine learning has been used on magnesium-based battery material.

New “one-pot synthesis method”
At the same time, Romio is testing magnesium as a new material for battery anodes (those electrodes that can accept electrons) in laboratory experiments. With magnesium electrodes one must first remove an oxide layer that normally covers this material and cover it with a protective layer of conductive magnesium alloy. “We will do this using a new ‘one-pot synthesis’ method and environmentally friendly organic acid solutions,” explains Romio. She and her colleagues will then characterize the properties of this “intermetallic intermediate phase” in detail, for example using electron microscopes, spectrometers, X-ray diffraction patterns and electrochemical analyses.

“Our goal is to synthesize the best possible surface for a magnesium-based anode,” says the researcher. Such an anode would then have to be combined with an available manganese-based cathode, thereby providing proof of the feasibility of a magnesium battery.

Austria is a magnesium stronghold
Compared to lithium, which is currently used in common anodes, magnesium offers several advantages, explains Romio: As an electrode material, magnesium has a higher capacity per volume than lithium, which means that the size of the batteries could increase with use. shrink. The material is more environmentally friendly and much more readily available: magnesium is the eighth most abundant element in the earth’s crust and Austria is the seventh largest producer of magnesite. This is an industrially important magnesium ore and is mined above and underground in Styria, Carinthia and Tyrol. “If the project produces good results, it will in principle be positive for the Austrian economy,” says the researcher. For example, magnesium ion batteries can be used as local energy storage devices or in “intelligent energy networks” (smart grids).