3 november 2023 Webmaster

Designing Batteries for Fast-Charging using Advanced Simulation and Testing

How can advanced cell characterization techniques be used for parameterization and validation? Dr. Jens Groot is currently holding the position as Chief Engineer Battery Systems at Polestar in Sweden where he supports advanced engineering work as well as participates in Polestar’s battery development. Before joining Polestar he worked with strategic battery R&D at Volvo Cars and as a technical specialist at Volvo Group. He received his PhD from Chalmers University of Technology, where the main focus of his research was on high-power Li-ion battery lifetime prediction and modelling. Dr. Groot is one of the speakers at Battery Tech for EV 2023 in Gothenburg on December 5-6 and we got the opportunity to ask him a few questions before the event.

Could you please introduce yourself and your work at Polestar?
I am an electrical engineer by training, ended up working with automotive battery & cell R&D for the past 20 years. This topic was so interesting that I also dove into an industrial PhD project within cycle life modelling and experimental testing – two topics I still find equally interesting. In my current role as Chief Engineer at Polestar I have the chance to both work with long-term R&D and more near-term engineering challenges related to our products. The pace of technology has never been faster which means that we can never, ever relax and consider our technical area as mature.

What will you speak about at Battery Tech for EV 2023?
I will bring up some recent R&D work within fast-charging and modelling, and how we aim to improve performance at the same time as reducing CO2 footprint.

What is happening in the research and development of fast-charging?
A lot! We have new cell formants, new cell chemistries, but also new integration methods and cooling system topologies. Added to that we also learn how to better utilize the data from onboard sensors and lab. tests, striving to better optimize charging.

What are the design challenges related to fast-charging?
On the system side, the number one challenge is to create an efficient and cost-efficient cooling system without sacrificing other properties such as light weight, serviceability or volume efficiency. Looking at the cell itself we need to learn how to optimize the charging algorithm further, for different chemistries, temperatures, state-of-charge regions and also charging patterns – EV users tend to have quite diverse behavior.

How can advanced cell characterization techniques be used for parameterization and validation?
Aside from lab. characterization, including precise calorimetric tests and post-mortem analysis, we have a fairly untapped resource in the huge amount of data available to the battery management systems in our cars in the field. Here we need to utilize this better, and to correlate what we see in the field with what we can test in our lab. We do not see an “either-or” relationship between analytical tools and data-driven methods.

What’s the most important thing you would like to share in your presentation?
I’d really like to point at the technical opportunities; how new materials and methods can help us on many fronts, e.g. not focusing on cost-efficiency separately from performance or circularity.

What are you most looking forward to by attending and speaking at the event?
I hope to get some new ideas related to battery/cell integration as well as methods – and to talk to other battery engineers and researchers of course!