A Michigan-based startup called Sakti3 claims it has battery chemistry that doubles the energy density of today's best lithium-ion batteries.

Speaking to Scientific American, Sakti3's co-founder and CEO Ann Marie Sastry says the firm's prototype solid-state lithium cells have reached 1,143 Watt-hours per liter--a number that wouldn't just transform an electric car's range, but its cost too.

Should we get excited? Yes and no.

Technology like this would certainly be beneficial for electric cars.

Energy density is something of a holy grail for the genre, because it increases the one aspect of electric cars most people are still unsure about: range.

The more energy you can pack into any given area, the more there is for the car to use to travel down the road. But there's another benefit to greater energy density, which is cost.

Once your electric car hits, say, 300 miles, only a tiny proportion of drivers would realistically need anything more. Chances are, the battery doesn't need to be as big, and the less battery you can get away with, the cheaper it is per car.

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Batteries have inherent cost of course regardless of how big they are, and Sakti3 is also working hard to bring down the all-important cost per kilowatt-hour. There are safety benefits too--solid state batteries are less volatile than ones with a liquid electrolyte.

Sakti3's battery is constructed using a thin-film deposition process similar to that seen in flat panel displays and photovoltaic solar cells.

As the solid-state definition implies there is no liquid electrolyte--a layer separates the anode and cathode and also acts as the electrolyte, through which ions transfer. The chemistry of this separating layer is currently a trade secret.

Which kind of sums up much of Sakti3's operations so far, and the reason we shouldn't be too excited just yet.

The batteries are, as yet, untested beyond the lab. Nor, as Scientific American points out, have the claims about energy density been independently verified. And most of the technical details are still a secret.

MORE: Hard Realities Of Battery Research: Promising Electrode Hasn't Panned Out

More positively, the company has caught the eye of General Motors, which has been looking closely into the technology for several years now. GM Ventures, the firm's technology investment arm, has even invested in the company.

GM's attention, or even money, is no guarantee of success--the recent failure of the nickel, manganese and cobalt cathode concept is evidence of that.

It does however give companies like Sakti3 a better chance of developing their technology. Sastry is confident too, saying that several internal tests on different cells have demonstrated the energy density numbers.

The company has reaped the benefits of advancements in other lines of technology, such as those solar cells and flat panel displays. Given the similarities in Sakti3's design, further developments in these differing industries could be advantageous. Not least in terms of cost.

Will this be the future of car battery technology? As ever, watch this space.


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