Here at GreenCarReports, we’re fans of all-electric cars, but even we have to admit that most electric cars on the market today suffer from the same problem: limited range.

But according to battery firm Envia Systems, the days of limited-range electric cars could soon be over, thanks to a new battery which almost triples the energy density of current electric car battery technology.

Better still, Envia claims its new battery technology is more than 50 percent cheaper than current generation electric car batteries, costing around $125 per kilowatt-hour.

Envia’s lithium-ion batteries use a Silicon Carbon Carbide (Si-C) nanocomposite anode, High Capacity Manganese Rich (HCMR) nanocoated cathode, and patented Envia High Voltage (EHV) electrolyte, which enables them to achieve an energy density of 400 watt-hours per kilogram.

That’s all very well, but what does it mean in real-world terms?

Envia Battery Technology

To help make a comparison, the current lithium-manganese battery pack the 2011/12 Nissan Leaf has an energy density of 140 watt-hours per kilogram, while the recently-retired Tesla Roadster has a battery pack energy density of around 130 watt-hours per kilogram. Envia's battery technology is more than triple that.

Put another way, if the current battery pack in a 2011/12 Nissan Leaf was replaced with a pack made of Envia cells -- and we assume that the weight of all the non-battery cell components of the pack remain the same weight -- it would store almost 61 kilowatt-hours of energy.

Using the EPA’s combined rating for the Nissan Leaf as a guide, that equates to a theoretical range of around 170 miles per charge.

Envia Battery Technology

“In an industry where energy density tends to increases five percent a year, our achievement of more than doubling state-of-art energy density and lowering cost by half is a giant step towards realizing Envia’s mission of mass market affordability of a 300-mile elerctric vehicle,” said Envia Systems Chairman and CEO Atul Kapadia.

That’s a breakthrough that hasn’t gone un-noticed, even if the battery technology might still be a few years from implementation in a production electric car.

In fact, Envia’s new battery technology has earned it a $7 million strategic investment from General Motor’s venture capital arm, along with a further $10 million from other interested firms during the same 2011 equity investment round.

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