Energy density for cars doesn't matter as long as it's above a certain minimum that lets the cars travel ~500km (~300 miles). Once they reach that number, car

Energy density for cars doesn't matter as long as it's above a certain minimum that lets the cars travel ~500km (~300 miles). Once they reach that number, car companies mostly care about cost - higher energy density reduces the weight of the car, which lowers the material costs of the rest of the car, but a big reduction on the cost of the battery does effectively the same thing. Ideally they want a dirt-cheap battery that's also high capacity, but then so does everyone.