There have been a few news about EV vans. Also Van conversion have been going for quite a while, you see a few on youtube. I'm surprised nobody have made an EV model already..
The Chryler Pacifica PHEV is basically a half EV van .. plugin hybrid with 30+ miles of electric-only range (with another 300-400 miles of hybrid/gas range)
An all EV van would be great but this is closest you can come today.