Published on November 9th, 2009 | by Susan Kraemer
Metal-Air Battery With 11 Times More Energy at Half the Cost?
US Secretary of Energy, Dr. Steven Chu
Arizona State University professor Cody Friesen thinks he can make a metal-air battery with up to 11 times the energy density of lithium batteries at potentially half the cost. Now the US Department of Energy’s advanced research incubator ARPA-E has just given his spin-off company, Fluidic Energy, a $5.13 million research grant to try and do just that.
ARPA-E funding is for breakthrough inventions that have the potential to radically change the way we get energy. Fluidic Energy holds this promise because a metal-air battery that uses an ionic liquid as its electrolyte (instead of water) would dramatically outperform the best lithium-ion batteries currently on the market.
An electric car with a relatively small battery could potentially travel well over 500 miles on a charge if his ionic liquid research pans out. This advance would leapfrog the electric car industry to well beyond the shorter-than-a-gas-tank range that has restricted the market appeal of electric cars.
The Metal-Air Ionic Liquid battery that Friesen and his researchers are designing will use ionic liquids as its electrolytes, instead of water-based electrolytes. Ionic liquids are salts that remain liquid in sub-zero temperatures or above the boiling point of water. Metal-air batteries have typically relied on water-based electrolytes; but they fail prematurely due to water evaporation.
Finding an ionic liquid to use instead of water would solve the problems that restrict the energy density of batteries now. Water also has a relatively low electrochemical window: it starts to decompose when the cell exceeds 1.23 volts. Because ionic liquids have electrochemical stability windows of up to 5 volts; it allows you to use much more energy-dense metals than zinc. The research team will target energy densities of at least 900 watt-hours per kilogram and up to 1,600 watt-hours per kilogram.
The US Department of Energy is currently headed by Nobel prizewinning scientist Dr. Steven Chu who spent much of his career at Lawrence Berkeley National Laboratory (LBNL). And it’s no surprise that Chu has tapped Arun Majumdar, the director of LBNL head up the ARPA-E program. Arun is responsible for materials science innovations such as using nanotechnology to harness the energy lost as heat during the production of electricity.
So their bet that this group can deliver a lower cost, better battery using a fundamentally new paradigm in electrochemical energy devices is probably a pretty good bet.
Fluidic Energy was one of 37 groups to receive a total of $151 million in funding from ARPA-E (the E denotes energy). It’s modeled on the successful Defense Advanced Research Projects Agency (DARPA) government funding that gave us, among other things; the ARPANET, the precursor of the internet.
Government funding of research has led to other game-changing technologies, notably the internet browser. Netscape founder Andreessen who created the first web browser, said of government involvement in its development; “If it had been left to private industry, it wouldn’t have happened.”
Image: Center for American Progress
Source: Technology Review