The problem isnt that its electric, its the amount of electricity drawn and the design of the fan.

There are some electric supercharges out there that do work, but they require extra batteries to be fitted and usually cost more than mechanically driven superchargers. This is because you need an electric motor that produces several HP to be able to spin an impeller with enough speed for the airflow and pressure required.

The other problem is that these electric supercharges are axial fans, not centrifugal fans. Axial fans can flow alot, which is why you see 800cfm+ of airflow being quoted, BUT they are very very poor when there is backpressure on the fan. Centrifugal fans are used in real turbo's and supercharges because they do work with back pressure so can actaully generate boost.

So they dont work because
a) wrong fan design, they might be able to keep up with the airflow of an engine but wont be able to generate boost

and b) the electric motors are simply too small.

But i didnt have to really say that because its all been said in NUMEROUS threads before.

impeller |imˈpelər| noun the rotating part of a centrifugal pump, compressor, or other machine designed to move a fluid by rotation. • a similar device turned by the flow of water past a ship's hull, used to measure speed or distance traveled.

An impeller is a rotating component of a pump, usually made of iron, steel, aluminum or plastic, which transfers energy from the motor that drives the pump to the fluid being pumped by forcing the fluid outwards from the centre of rotation. Impellers are usually short cylinders with protrusions forming paddles to push the fluid and a splined center to accept a driveshaft.