I have answered earlier on my reading of Rowan’s piece, and why I understood it differently.
I agree with him that cars (= batteries) need to be lighter. That in itself will improve range. The battery technology itself must find a better alternative to Lithium because of the cost (monetary and ecological) and the limited number ( and the identity) of suppliers.
In other words, EV in 10 years time will be very different from what they are today. The market itself will be vastly different too, and it’s likely our use will have changed significantly too.