The Future of Battery Technology for Electric Vehicles and Solar Energy Storage

8 Potential EV and Hybrid Battery Breakthroughs
Article from 2012 that covers a slew of different technologies.  One of the most promising battery technologies is being developed by IBM and uses oxygen for Lithium Air Carbon.  It's been coined a 'breathing' battery that expels oxygen when the battery is recharged.

Lithium Silicon could reduce the charging time needed since silicon can expand and contract as it absorbs and discharges ions.  It is being developed at Northwestern University.

A Carbon Foam Capacitor Hybrid could combine the energy storage density of traditional chemical batteries with the delivery efficiency of a solid-state capacitor.  "The unit can be recharged thousands of times without showing signs of degraded performance."

Lithium Silicon Polymer would store more energy than the batteries used in current EVs because the contacts between connections between electrodes are not broken when they expand and contract.

Lithium Sulfur Carbon Nanofiber uses "carbon nanotubes coated on the inside with sulfur" that could store up to ten times the the energy of regular lithium batteries.

Lithium Manganese Composite/Silicon Carbon Nanocomposite 
Envia's primary development is a proprietary cathode material based on manganese, an abundant metal that is stable when used in the battery. Manganese is also less expensive than the more common cobalt-based cathode material, Envia says. The firm has received grants from U.S. auto companies and federal and California energy agencies to continue developing the battery for commercial use; it says the battery could give a range of 300 miles in an EV.