There's 3 major roadblocks that electric cars need to overcome to become more common:

1) The costs need to come down so they're comparable to similar gas-powered cars
2) A full charge needs to last at least 300 miles so people can go on long-distance journeys
3) (this is the hardest one) A full charge needs to be done in 5 minutes so it's comparable to the amount of time it takes to fill up gas. I can't use a vehicle that takes 8 hours of charging to give me a full tank.