That's certainly possible, yes. It's sometimes called a "series hybrid". While conventional "parallel" hybrids have both gas and electric engines connected to the drivetrain, in a series hybrid the drivetrain is 100% electric, but there's also a gas generator that feeds into the electric system when needed.
Whether you should call that en electric vehicle or not seems to depend on what proportion of the energy is expected to ultimately come from gas vs. wall charge. If most of the energy comes from gas, then it's just a different configuration of hybrid vehicle. Diesel trains work that way, for example (electric drivetrains powered by a diesel generator), and are not considered electric trains. On the other hand, if it runs mostly electric and there is a tank just used for occasional range-extension, those are being marketed as "extended-range electrical vehicles".