That's engineering, not physics. There is a lot of chemistry research that goes into battery technology, but AFAIK Tesla's batteries use tried-and-proven lithiu

That's engineering, not physics. There is a lot of chemistry research that goes into battery technology, but AFAIK Tesla's batteries use tried-and-proven lithium ion tech. Also, he dropped out of his Ph.D. on the first week. So it appears that he didn't learn too much physics in academia. Rocketry and electric cars don't involve too much advanced physics and he has top notch experts working for him in all the relevant fields.