Rising expectations placed on electromobility – shorter charging times and longer range – are driving engineers to push the limits of what is feasible in battery technology. The attraction and challenge lies in resolving technical contradictions. For example, between increasing energy density and safety, or between development and material costs and price pressure.
“Everyone wants ultrafast charging – ten minutes of charging time for a range of 400 kilometers. But the energy acting on the battery system is twice as intense as a race on the North Loop of the Nürburgring,” Kritzer explained. This is why thermal management is a major topic in the industry and why Kritzer and his colleagues in the E-Mobility team find themselves asking: What components can Freudenberg develop to make lithium batteries for electric cars safer?
This consideration also gave rise to the DIAvent pressure equalization valve, which makes electric vehicles safer. It fulfills two functions. In normal operation, it allows the battery to “breathe”; in the event of a malfunction – for example, if a defective battery cell overheats – it provides emergency venting and prevents the dreaded chain reaction of thermal runaway.
Kritzer’s thoughts have long since turned to other possible solutions, including emergency cooling concepts that quickly and specifically direct cooling media to where components overheat in the event of a malfunction. The basic idea is to use a foil that melts and releases a cooling component as soon as the temperature exceeds a certain threshold. “This is more efficient than peppering the entire system with sensors”, said Kritzer.