This and other ideas are now being explored. Batteries at the moment are not efficient enough for total general use although in combination with other fuel sources they seem to be progressing. Research is ongoing.

I remember reading about an experimental European car a few years ago that used a battery system coupled with pedal-power for the driver/passenger. The car did not run totally on battery power, but also did not have to rely totally on pedal power either. I seem to recall that it had a range of 60 to 100 miles starting with a full overnight charge and using moderate but continuous pedalling from one person. If the embodied energy in photo-votaics ever gets low enough to be economic, one could add a solar skin to such a vehicle.

I personally think that the major obstacle to electric vehicles lies more in human nature and aggressive driving habits, and the major auto makers around the world understanding the preferences of their mass market. However, in all honesty, this is an opinion based more on cynicism than actual research.

There is current research in the use of methyl alcohol driven fuel cells to replace batteries in electric equipment, especially for military use to combat the problems of battery innefficiency and weight in mobile units. Prospects look good and perhaps this research can be extended to vehicular propulsion.

http://www.utdallas.edu/news/2008/09/19-001.php really good article about research into capacitors as a better storage method than batteries