They knew the problems, they just didn't give a shit because they're not being held responsible for their unsafe, dangerous products. These days you can get away with anything as long as it's marketed as "eco-friendly". So they're going to continue using the cheapest, shoddiest methods out there. Why research and build new factories for vehicle-safe fuel cells? Much easier and cheaper to use existing manufacturing chains and slap together phone batteries into unstoppable chemical fires.