I started thinking that you could get the speed up using a traditional electric motor. Then to sustain that rotation. I wonder. As a concept. Could you use something else to sustain that rotational speed. Something much more efficient perhaps.
Similarly. Applying this concept to magnetism. There could exist a starter coil and a more efficient system applied later on.
Also for batteries. Could a small efficient flywheel generate high enough amps. Even from a failing battery or small irregular voltage battery. For a mobile this is not possible but for a truck or car a flywheel could maybe be built in.