Couldn't you just use an electrically-driven turbo compressor to produce a source of hot, high-pressure gasses? Not saying the efficiency or mechanics would play out at scale, but hypothetically you should be able to generate any arbitrary source flow required to feed through this type of nozzle.
In theory? Maybe, but the motor would probably weight more than the whole plane does now. A typical jet engine is producing the equivalent of tens of thousands of horsepower.
