The Holy Grail, at least for now, is solid-state battery technology. Nikkei reports that Toyota, along with partners Tokyo Institute of Technology and High Energy Accelerator Research Organization, have developed a prototype solid-state battery that could be ready for commercialization in the 2015-to-2020 time frame.
Here's why sold-state batteries are such an improvement:
As you can see, a solid-state battery has numerous advantages over its liquid electrolyte counterpart, including simpler fabrication, stability, safety and excellent conductivity. The hard part is turning this theory into reality.Since the [solid state] battery can easily be processed into sheet form, it can store several times the amount of electricity, volume for volume, than the current generation of electric vehicle batteries, according to the developers. This added capacity may extend the maximum driving distance per charge for compact electric vehicles to around 1,000 kilometers [621 miles] from the 200 km [124 miles] or so for existing vehicles.