A modern jet is just a turbine driving a large fan inside a duct. An electric jet would work by removing the turbine and having an electric motor in place. Or

A modern jet is just a turbine driving a large fan inside a duct. An electric jet would work by removing the turbine and having an electric motor in place. Or possibly around the edges. This sort of design is called a ducted fan, It'd be more efficient through smaller losses and probably a smaller drag (less flat plate area).