A Little Good News

While I can tend to get a bit pessimistic at times about the global economy (actually... I'm not really pessimistic... probably the best thing the economy can do right now is contract: it means gas will become relatively more expensive and we'll have more market incentive to create clean alternatives), it helps to see some positivity sometimes:

Envia Systems, backed by venture capitalists, General Motors, and the Department of Energy, plans to announce on Monday at the ARPA-E conference that the company has created a lithium ion battery that has an energy density of 400 watt-hours per kilogram, which Envia CEO Atul Kapadia told me in an interview could be the tipping point for bringing electric cars to mainstream car owner.
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Kapadia tells me that current lithium ion batteries deliver an energy density of around 100 to 150 watt-hours per kilogram, while Envia’s battery can deliver 2.5 times that energy with about the same weight as the current electric cars that have hit the market. To build a 300-mile range electric car with standard lithium ion batteries, it would cost around $40,000 just for the batteries alone, says Kapadia.
Envia says with an energy density of 400 watt-hours per kilogram, its battery cell costs could be at $125 per kWh.

That's very good in relation to other battery technologies. Just to shed a little gloom on the topic, though, the energy density of gasoline (or petrol) is 47.2 MJ/kg. The Envia Li-ion battery energy density is 1.44 MJ/kg. We're only off by a factor of 32 give or take, but it's better than nothing. Li-air batteries have an energy density of 9 MJ/kg, so there are other technologies out there that might supplant Li-ion, but for now, I'll take what I can get.