TU Graz develops guidelines for repairable EV batteries
Researchers at TU Graz have developed design guidelines to make traction batteries safer and easier to repair and recycle. Their analysis shows that repair-friendly designs can pay off economically and environmentally if only 8% of the battery cells are reused.
A research team led by Graz University of Technology (TU Graz) has compared three battery pack designs to determine how their construction affects safety, repairability and sustainability. The first reflects a common approach using bonded housings and thermally conductive pastes. While such designs have advantages in production, even limited damage can mean replacing the entire battery pack.
The researchers compared this with two designs intended to make repairs easier. One combines replaceable housing covers with heat dissipation pads, while the other uses an electrically insulating oil for liquid cooling and a screwed and sealed housing. The latter allows the battery to be dismantled and individual cells to be replaced.
The work was carried out as part of the E-Track research project and aims to address the lack of standardised designs for traction batteries.
The cells themselves are particularly important when it comes to whether repairs make sense. They account for around 75% of a battery pack’s total mass and are also its biggest cost factor. According to the project’s life-cycle analysis, a repair-friendly design already pays off if 8% of the cells can be reused after an accident. Easier disassembly also makes it simpler to recover materials for recycling.
“Without uniform design standards, emergency services often face major challenges in an emergency because the structure and behaviour of battery systems are difficult to assess. At the same time, we lose valuable resources if batteries cannot be repaired or fully recycled,” said Markus Fasching, project manager at TU Graz’s Vehicle Safety Institute. “Our work shows that safety, efficiency and recyclability can be improved together through well thought-out design.”
E-Track also looked at how damaged cells can be identified before they cause problems. The team developed diagnostic methods combining electrochemical impedance spectroscopy with virtual multiphysics models. The approach can detect internal damage such as micro-shorts, which may otherwise cause a battery fire at a later stage.
Although the project focused primarily on batteries for electric two-wheelers, its methods and simulation approaches are also applicable to larger vehicles, including cars and lorries. The researchers say the results could provide a basis for future industry standards and potentially regulatory frameworks.