A metal-air battery that uses ionic liquids as its electrolyte could have several advantages. For one thing, it can function for a longer period time since its electrolyte doesn't evaporate. Also, the batteries could offer better electrochemical stability, which means they could use materials that have a greater energy density than zinc. Friesen and his research team hope to achieve energy densities of anywhere from 900 to 1,600 watt-hours per kilogram. This density could lead to electric vehicles that could 
PhysOrg.com - A spinoff company from Arizona State University plans to build a new battery with an energy density 11 times greater than that of lithium-ion batteries for just one-third the cost. With a $5.13 million research grant from the US Department of Energy awarded last week, Fluidic Energy hopes to turn its ultra-dense energy storage technology into a reality.
"I'm not claiming we have it yet, but if we do succeed, it really does change the way we think about storage," Friesen said.
via: Technology Review
