A U.S. government-backed Silicon Valley company says it has reached a key milestone that will much-reduce the cost of producing lithium-ion batteries, whose high pricetag has been the primary hurdle making electrified cars prohibitively expensive. Envia Systems, whose shareholders include General Motors, said its improvement allows an electrified vehicle to travel for 300 miles at half the cost for the battery pack. If proven on a commercial scale, the advance could bring the price of electric and plug-in hybrid vehicles much closer to a par with pure gasoline-driven models.

There are almost weekly claims by private and university scientists to have broken through key technical hurdles preventing the commercialization of electric cars, but Envia CEO Atul Kapadia told the New York Times' Jim Motavalli that the improvement is different. "What we have are not demonstrations, not experiments, but actual products. We could be in automotive production in a year and a half," Kapadia said.

The technology is built from a breakthrough made at Argonne National Laboratory, which licensed the advance to Envia in 2008. Envia also received a $4 million grant from ARPA-E, the radical energy research laboratory at the U.S. Energy Department. GM invested an additional $7 million in the Newark, Ca.-based company. (Envia posted some of its lab data here).

The advance is in energy density -- the number of watt-hours per kilogram of kilogram of battery material. Envia says its battery cells deliver 400 watt-hours per kilogram, or more than twice the best performance currently on the market. Kapadia called the 400-watt-hour level "the holy grail of electric cars," writes Sarah Mitroff at VentureBeat. If GM could commercialize the development somewhere on the scale that Envia describes, it could make the $41,000 Volt much more affordable, writes Mitroff.

Envia's lower cost battery will give GM the chance to lower the cost of the Volt, making it more available to the general car buying public. In addition, other car companies could use the technology to create economically viable cars that could compete with gasoline-powered economy models.

Envia's announcement comes against a black eye suffered by the Energy Department for its investment in Solyndra, a solar panel company that has filed bankruptcy. To the degree the technology is proven out, it could be a public-relations boon for Arpa-E.