By all indications, there will be an all-electric 2017 Chevrolet Sonic EV for which General Motors is targeting a range of 200 miles.

And one of the keys to achieving such a range from a compact car will be a more energy-dense battery than those used today.

DON'T MISS: GM's 200-Mile Electric Sonic EV For 2017: What We Know So Far: UPDATED

One contender is clearly LG Chem, which now provides cells for both the Chevy Volt range-extended electric car and the Chevrolet Spark EV electric minicar, a compliance car sold only in a few states.

Ann Marie Sastry, CEO of startup lithium-ion cell maker Sakti3

Ann Marie Sastry, CEO of startup lithium-ion cell maker Sakti3

But there's another company that might possibly provide cells for longer-range GM electric cars: Sakti3, the secretive startup founded in 2008 by former University of Michigan engineering professor Ann Marie Sastry.

It's one of two startup battery companies that received investments from GM Ventures, the company's venture-capital arm.

The other company, Envia, has received more media attention, largely because it has apparently failed to deliver on its promise of a cheaper cell with greater energy density.

ALSO SEE: Collapse of Battery Startup Envia: What Really Happened

In fact, Sakti3 got its GM investment in September 2010, a couple of months before Envia, which received its funding in January 2011.

Now Sakti3 is starting to emerge from the shadows.

It's worth reading Fortune magazine's profile of Sakti3 as a company, which delves into the battery chemistry and the substantial challenges it still faces.

(The company's name comes from the word "sakti," which means power in Sanskrit, plus the atomic number of the element lithium, which is 3.)

In August, Sastry said the company's solid-state cell was close to doubling the energy density of today's lithium-ion cell chemistries, at just one-fifth of their cost.

Volt Battery Pack

Volt Battery Pack

That would, the company suggested, lead to a battery cost of just $100 per kilowatt-hour by the end of the current decade.

For perspective, that's less than half the cost projected by Frost & Sullivan, among other industry analysts.

Such a price would make electric cars with battery packs of 50 to 100 kWh hugely more affordable.

That would come just when tougher fuel-economy and carbon-emission rules in North America, Europe, and Asia will have ramped up significantly--raising the cost and complexity of gasoline- and diesel-powered vehicles.

MORE: 2016 Chevrolet Volt To Launch Next Year: What We Know So Far

The proof will be in the pudding, and GM will only comment on its battery suppliers for future products when it's ready.

Sakti3 still faces huge challenges, the biggest of which is "the cost of manufacturing and the yield it’s going to get," according to Kevin See, a Lux Research analyst quoted by Fortune.

"It’s great to demonstrate a small battery in the lab," See said, "but making batteries bigger and making a lot of them is not trivial."

But Sakti3 appears to be one to watch--and will likely receive far more attention in future than it has thus far.


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