TU Graz is developing guidelines for repair-friendly traction batteries
Researchers at TU Graz have established design guidelines in the “E-Track” research project to make batteries safer, easier to repair, and more recyclable. Their analysis shows that battery pack designs that facilitate repairs are beneficial both economically and environmentally.
A research team led by the Technical University of Graz (TU Graz) compared three battery pack designs to determine how their construction affects safety, repairability, and sustainability. The first pack resembled a common model with a glued casing and thermal paste. Although such constructions offer advantages in production, even minor damage can require the replacement of the entire battery pack.
The researchers compared this standard pack with two designs intended to simplify repairs. One combined replaceable casing covers with heat transfer pads, while the other used an electrically insulating oil for liquid cooling along with a screwed and sealed casing. The latter allows the battery to be disassembled and individual cells replaced.
The cells themselves play a particularly important role in deciding whether repair is worthwhile: they make up around 75% of the total mass of a battery pack and are also its largest cost factor. According to the life cycle analysis by the Graz project team, a repair-friendly design pays off even if only 8% of the cells can be reused after an accident. Simpler disassembly also facilitates the recovery of materials for recycling.
"Without unified design standards, emergency responders often face significant challenges in critical situations because the structure and behavior of battery systems are difficult to assess. At the same time, we lose valuable resources when batteries cannot be repaired or fully recycled," explains project leader Markus Fasching from the Institute for Vehicle Safety at TU Graz. "Our work shows that safety, cost-effectiveness, and recyclability can all be improved together through thoughtful design."
As part of the E-Track project, researchers also explored how damaged cells can be identified before they cause problems. The team developed diagnostic tools that combine electrochemical impedance spectroscopy with virtual, multiphysical models. According to the researchers, this approach allows “reliable detection of internal damages such as micro-short circuits, which otherwise could lead to critical events like battery fires over time.”
Although the project focused primarily on batteries for electric two-wheelers, its methods and simulation techniques can also be applied to larger vehicles such as cars and trucks. The researchers say the findings could serve as a basis for future industry standards and possibly even legal regulations.