Which technology will inherit lithium-ion batteries?
The development of new batteries has been in full swing for years, but new lithium-free batteries for mobile use will still take some time before they are ready for the market. Researchers are therefore also working on optimising the production of established lithium-ion batteries. Although these batteries have been in commercial use since 1991, there is still a lot of potential for optimisation in their production.
Researchers at the Chair of Production Engineering of E-Mobility Components at RWTH Aachen University have identified around 2,100 cause-and-effect relationships that can reduce cell quality in the production of lithium batteries. Even small deviations in electrode production, cell construction and cell finalisation can have a massive impact and lead to rejection rates of over 10 percent.
With the help of AI data analyses, the error rate should be significantly reduced in the future. Specialised AI applications carry out automated root cause analyses to identify the causes of quality deviations. In addition, AI applications monitor the condition of the machines in the production line. This allows problems to be recognised at an early stage and avoided through intelligent, proactive maintenance planning. Overall, these AI approaches promise significant increases in efficiency, quality improvements and cost savings that can be realised in the short term.
At the Pacific Northwest National Laboratory (PNNL), a research facility of the US Department of Energy, a battery research project recently caused a stir. Together with the software company Microsoft, the researchers used AI to search for suitable materials for new batteries that use significantly less lithium without losing the advantages of the ultra-light metal. A total of 32 million potential materials were analysed.
The enormous capabilities of the AI were evident not only in the amount of data to be processed, but also in the speed: after just 80 hours, 18 materials were identified that can now be used for further research. Normally, this process in research takes several years or even decades. At PNNL, however, an initial prototype has already been developed that uses 70 per cent less lithium.
Another starting point for the sensible use of AI in battery development is analysing usage to improve service life. Prof Ralf Herbrich is researching this at the Hasso Plattner Institute (HPI) in the field of ‘AI and Sustainability’ in cooperation with a Berlin start-up. Together, they are developing algorithms that can record various wear factors in batteries and draw conclusions for optimal utilisation. In the case of batteries in electric cars, for example, these factors include driving style, the characteristics of charging processes and temperature windows during charging.
The aim of this work is to physically understand ageing processes without having to open the battery. The start-up ‘betteries’ then wants to use the findings to give used batteries a second life after they have been removed from the electric car. This would also improve the carbon footprint of the batteries, as around 500 charging cycles with renewable energy are currently required to save as much CO2 as was previously released during production. A longer service life would therefore be desirable. In any case, the research project is optimistic that the number of charging cycles can be at least doubled, tripled or even increased tenfold with AI support.