Autoblog has more on the discovery:
A group of Massachusetts Institute of Technology students may have come up with the perfect solution to our electric vehicle charging woes. Instead of relying on lithium or nickel, the new battery design stores its electrons in semi-solid flow cells. Charged particles are suspended in an electrolyte solution and pumped between compartments used for storing or releasing energy. The tech supposedly makes the batteries up to ten times more efficient than their traditional counterparts, and even more importantly, the new tech is cheaper to produce. Estimates say that the design could cut the size and expense of current batteries by as much as 50 percent.