Is it possible to have a fully electric airliner?
Well, to use the same airframe, you'd basically have to find a way to replace the fuel volume in the wings with battery volume, and batteries are somewhere around 15-20% of the power density of fuel, as the answers in this ASE post lay out pretty well.  

So if you had an electric fan that made the required thrust, and somehow figured out how to replace all the fuel tanks with batteries, you'd probably have something, but only with about an hour's endurance, which wouldn't even make up the IFR reserve range requirements most of the time.  You would have to replace a lot of pax with batteries to get even a couple hours endurance, which would kind of kill the business case.

So that kind of concept is pretty much a dead end until battery power density starts to approach the level of kerosene, maybe 20 or 30 years from now unless some massive new development comes along.