[aerodude]

Yeah you could; you would probably place the batteries in the wing where fuel is located, which potentially has benefits.

I was pointing out that the reasoning was flawed. The engine is not the limiting factor in the design of the wing, and in fact can let you reduce the mass of the wing. An electric motor and airframe might be lighter than an engine and airframe depending on the design. However, you do need to compare the battery weight with the fuel weight, because the energy has to come from somewhere, and an airframe is designed with that reduction in weight in mind. It's hard to stress just how important energy density is for an aircraft.