A new breakthrough from California-based Envia Systems will yield lithium-ion batteries that are less than half the cost of current cells, while also having three times the energy density. And guess who funded it? The Department of Energy. That’s right: Sometimes, when the government invests in innovation, it pays off moon launch-big.

Envia’s announcement said that its packs would deliver cell energy of 400 watt-hours per kilogram at a cost of $150 per kilowatt-hour. Though it doesn’t disclose a cost breakdown, Tesla Motors rates the energy density of its Roadster’s pack at 121 watt-hours per kilogram. Envia said its energy-density performance was verified in testing of prototype cells at the Naval Service Warfare Center’s Crane evaluation division.

Envia’s breakthrough happens to match the price/performance point that some analysts consider the “holy grail” of battery characteristics required for mass commercialization. Which means that within a decade or so, cars like the Nissan Leaf and the Chevy Volt could be as popular as iPads.