A group of young MIT students has developed a new type of battery that runs on a rechargeable liquid fuel. The inventors call the fuel "Cambridge Crude," and if the technology makes it to market, refueling an electric car could be as easy as pulling up to a pump. The batteries are powered by semi-solid flow cells, an innovative architecture that uses charged particles floating in a liquid electrolyte between two containers--one for storing energy and one for discharging energy. Separating out the functions and other innovations make the new battteries ten times as efficient as similar existing technology and cheaper to manufacture than lithium-ion batteries. In short, the new batteries make irrelevant the size and cost limitations that have kept this kind of technology out of electric cars to date. The MIT News Office reports:

The new design should make it possible to reduce the size and the cost of a complete battery system, including all of its structural support and connectors, to about half the current levels. That dramatic reduction could be the key to making electric vehicles fully competitive with conventional gas- or diesel-powered vehicles, the researchers say.

Another potential advantage is that in vehicle applications, such a system would permit the possibility of simply “refueling” the battery by pumping out the liquid slurry and pumping in a fresh, fully charged replacement, or by swapping out the tanks like tires at a pit stop, while still preserving the option of simply recharging the existing material when time permits.

According to supervising professor Yet-Ming Chiang, the group originally set out "to reinvent the rechargeable battery" and expects to have a fully operational prototype that could be manufactured for electric cars in the next 18 months.