BAM uses face recognition algorithms to improve environmental balance of electric batteries

Based on the distribution of lithium isotopes, the ageing of lithium-ion batteries can be determined and evaluated

Lithium isotopes are deposited on the electrode of a battery in a characteristic way. The ageing state can be determined with face recognition software. Source: BAM

The Bundesanstalt für Materialforschung und -prüfung (BAM) has developed an innovative method that uses algorithms from face recognition to determine the ageing of lithium-ion batteries. The method is intended to help companies develop longer-lasting and at the same time safer batteries and thus improve their environmental balance.

Lithium batteries are particularly susceptible to ageing processes. During each charging and discharging process in an electric battery, lithium ions are deposited in the electrodes of the cell like in the pores of a sponge. Over time, however, fractures and cracks occur in the filigree structures. The result: more and more lithium ions no longer fit into the hollow spaces of the "sponge", instead they accumulate in heaps around the electrodes and hinder the movement of other ions. The performance of the battery decreases.

The cluster formations show characteristic patterns: because lithium occurs in nature in two different isotopes. "We now know that the distribution of lithium isotopes in a cell is directly related to its age," explains Carlos Abad, head of the project. The chemist and his colleague Dalia Morcillo have analysed this distribution in more detail using spectral analysis.

In the process, lithium ions are excited with light, which they absorb to different degrees. "The images of these isotope spectra are hardly distinguishable to the naked eye," explains Dalia Morcillo. "They resemble each other like the faces of twins."

This gave the team the idea of using algorithms from face recognition for the evaluation. In this way, they found a method that can be used to quickly determine the isotope distribution in a cell.

"In the next step, we want to provide companies that produce lithium batteries with a fast and cost-effective method to evaluate the ageing behaviour of their batteries already in the laboratory," says Carlos Abad. "This should make it possible to make batteries more durable and ultimately more sustainable in the future."

More about the team's work can be found in the BAM Report 2021/22, pages 36 - 39.
 

Contact:

Bun­des­an­stalt für Materialforschung und -prüfung (BAM)
Division Inorganic Reference Materials
Email presse(at)bam.de
www.bam.de

Press release BAM, 12 April 2022