A new Concept for Better and More Sustainable Batteries

Researchers have developed a new concept for aluminium batteries, which will give them twice the energy density with reduced environmental impact

Researchers from the Chalmers University of Technology, Sweden, and the National Institute of Chemistry in Slovenia have developed a new concept for aluminium batteries, which will give them twice the energy density as compared to previous versions, with reduced environmental impact and production costs.

The team believes that the idea has the potential for large scale applications, including storage of solar and wind energy.

Using aluminium battery technology could offer several advantages, including a high theoretical energy density, and the fact that there already exists an established industry for its manufacturing and recycling is a big advantage.

Compared with today’s lithium-ion batteries, the researchers’ new concept could result in markedly lower production costs, reported the study published in the journal, ‘Energy Storage Materials’.

“The material costs and environmental impacts that we envisage from our new concept are much lower than what we see today, making them feasible for large scale usages, such as solar cell parks, or storage of wind energy, for example,” said Patrik Johansson, professor at the Department of Physics at Chalmers.

“Additionally, our new battery concept has twice the energy density compared with the aluminium batteries that are ‘state of the art’ today,” he added.

Previous designs for aluminium batteries have used the aluminium as the anode (the negative electrode) – and graphite as the cathode (the positive electrode). But graphite provides too low an energy content to create battery cells with enough performance to be useful.

In the new concept, presented by Johansson and Chalmers, together with a research group in Ljubljana led by Robert Dominko, the graphite has been replaced by an organic, nanostructured cathode, made of the carbon-based molecule anthraquinone.

The anthraquinone cathode has been extensively developed by Jan Bitenc, previously a guest researcher at Chalmers from the group at the National Institute of Chemistry in Slovenia.

The advantage of this organic molecule in the cathode material is that it enables the storage of positive charge-carriers from the electrolyte, the solution in which ions move between the electrodes, which make possible higher energy density in the battery.

“Because the new cathode material makes it possible to use a more appropriate charge-carrier, the batteries can make better usage of aluminium’s potential. Now, we are continuing the work by looking for an even better electrolyte. The current version contains chlorine — we want to get rid of that,” said Chalmers researcher Niklas Lindahl, who studies the internal mechanisms which govern energy storage.