> 20% less energy dense than lithium ion That's 20% as dense (1/5 the density), not 20% less dense (4/5 the density). As for replacing the chassis—a Tesla Mod

> 20% less energy dense than lithium ion That's 20% as dense (1/5 the density), not 20% less dense (4/5 the density). As for replacing the chassis—a Tesla Model S has 1,200 lbs of batteries, and the aluminum chassis weighs 410 lbs. Assuming this new material replaces the aluminum pound-for-pound, that would store enough energy to displace about 82 lbs of ordinary lithium ion batteries for a ~5% reduction in total weight. If the energy density were somehow on par with lithium ion then it would save 410 lbs, or 25% of the total weight.