While the heat shields and fire extinguishers for vehicle batteries are still in development, Freudenberg has other solutions far closer to series production. Several customers are now testing a new vent valve for battery housings. The valve combines two functions previously requiring separate components. One is the normal pressure compensation needed when hermetically sealed housings are exposed to significant changes in elevation. “An electric vehicle needs to travel in the mountains without bunging up the battery,” says Kritzer. The valve also provides emergency ventilation. Should gas escape from a damaged battery cell, it is immediately vented. “Batteries with higher energy density will not have a lot of air,” explains the expert. “Without an emergency vent, the pressure inside would rise so quickly that the battery could burst.”
The idea behind the DIAvent valve is simple: depending on whether the air pressure needs to be gradually regulated in normal operations or an emergency requires a rapid change, a patented mechanism alters the cross-section surface for the air flow. “The simple ideas help solve big problems,” says Kritzer. However, he cannot move from an inventive idea to series production on his own, he needs help from experts in design, materials, testing technologies and from many other fields. “In the end, a successful new product is always the result of teamwork.” Even though the start is sometimes just a solitary stroll in the woods.