Electric recumbents have not been around for more than a handful of years.  This is not really that surprising since as far as the mass market is concerned, normal recumbents have not been around for a very long time either.

The normal recumbent can probably trace its history back to the older reclining bicycles that people started using about a decade ago.  They never really caught on however, as most people still prefer the normal upright bicycles or tricycles to the reclining recumbents.  Recumbents are starting to get more popular with the passage of time however, so it is quite possible that the future will be quite different from the lessons taken from the history of recumbents.

Full electrification of recumbents has not been attempted to this date.  This is because many recumbents are actually manual more than they are anything else.  They come with pedals that people can work when they want to move the recumbent forward.  To this date, the electrification of recumbents has really only involved the addition of battery-powered engines to the recumbent so that a person that does not want to pedal can quickly turn on the engine and let it do the work for them.

In other cases, the pedal and the engine have been able to work in tandem.  These are known as electric-assist recumbents and they have been far more popular than their fully electric counterparts so far.  Of course, with just a few years worth of history to go on, it is difficult to say what the long term trend might be.

On a small scale especially, electrification tends to become quite expensive when compared with combustion because one is mass produced and one is not.  This, when combined with the issue of the lack of a lightweight electricity storage solution, is something that really sets the electric industry aside as being one that is not ready yet for prime time.

This has a special significance when it comes to the electric recumbent industry.  When a person is pedaling furiously and trying to get their recumbent from point A to point B, the presence of one or two batteries under the seat is not something that makes pedaling any easier.  This is why electric assist is actually not viewed as a viable option by many. It would not be surprising if eventually fully-electric recumbents took the industry from electrically-assisted vehicles, grabbing the entire market share in the process.

In the grand scheme of things, this is really just an academic debate.  Recumbents are not popular vehicles.  It is arguably true that more people make them in their garages at home than actually purchase them from dealers.  As long as that remains a debatable point, you should look to other wheeled individual vehicles for the eventual electric revolution.