Steam propulsion using turbine generator to electric motor to drive screw is nothing new. US Navy has had several versions.
Look up Stanley Steamer. Probably easier and cheaper to use direct recip steam engine to drive mechanism ie rear axle or whatever.
The main drawback is how long it takes to build steam. Other drawbacks very expensive if you are not a machinist, certified (or just competent) pressure vessel and pipe welder, boiler tender / operator, and expert mechanic and electrician.
The weight savings from no battery will go right down the tube (or vaporize to be humorous) in the weight of a steam plant and auxiliaries.
