Ionic Batteries Could Increase Mobile Device Runtimes Six-Fold



Could the six-hour runtime of a netbook go to 36 hours in the future? It sounds possible based on recent ionic battery projects. Battery technologies simply haven’t undergone a major change in years, so most of our runtime gains have come through more power efficient hardware. But if I’m reading the news right, ionic liquid powered batteries might be the breakthrough to change that. According to Cody Friesen, a professor of materials science at Arizona State and founder of Fluidic Energy:

“[A] metal-air battery using an ionic liquid as its electrolyte not only functions significantly longer–because drying out is no longer a problem–but it also gets a big boost in energy density. “These liquids have electrochemical stability windows of up to five volts, so it allows you to go to much more energy-dense metals than zinc.” He says his research team will target energy densities of at least 900 watt-hours per kilogram and up to 1,600 watt-hours per kilogram in the DOE-funded project.”

As I see it, this technology is really geared for electric vehicles with large batteries. But I could envision this technology making its way down to notebook batteries. And if it did, you could “cram” more energy in a battery without increasing the size and weight.

Some quick math using the project’s median target shows why I’m hoping this comes to pass. If a 1 kilogram / 35.5 ounce ionic battery can hold 1250 Whr of juice, that’s about 125 Whr per 0.1 kilograms / 3.5 ounces. That works out to an energy density of 35.7 Whr per ounce of battery weight. The battery of my Toshiba NB205 battery weighs 11 ounces, so an ionic battery of similar weight could offer 392 Whr as opposed to the 63 Whr my current battery offers. I’m all for more efficient electric cars, but the ability to run my netbook for nearly a week of work time is pretty appealing too.



I think this will be great… in five years or so when it’s a real product. ;) Hopefully it will be targeted at consumers and not the elite. (They CAN make much more efficient solar cells than the ones we see in our toys)

@ Kevin my Dad used to work for DOE and lets just say that proposals for government grants and internal politics and such would mean that they are hoping to hit 900wh and 1600 is just for show.

Even still using 900wh and removing 10% for packaging your Toshiba’s bat would pack 250wh and a 4x increase ain’t bad! Maybe then you could turn the screen up to “medium”. ;)

Doug Mohney

How far out do you define “the future”?

You barely, BARELY see Zinc-Silver notebook batteries out there. Maybe one?

Methanol fuel cells? Well, there’s ONE or TWO available in Japan this year after years and years of jawboning and press releases… *sigh*.

Even the talk of retooling Lion batteries with various silicon-based processes has all been for naught…

Forgive me, but talk of speculative breakthroughs after about a decade of battery and fuel cell hype just hit the angry button.


Energy density is indeed the bottom line when it comes to battery performance. Each step from NiMH to LiIon and now LiPoly has bumped up cell density along with improving self-discharge rates. I am a bit concerned though of how a liquid battery will work in a mobile device, since with automobiles the batteries are designed to be maintenance free, are never touched, and are packaged more robust. Batteries for electronics have always been solid cells, negating the need for thick skin plastics. It may take several years before they can work out the kinks and make these feasible for notebooks, and by then this may not even be the most suitable technology.

Kevin, the battery on your NB205 is a LiIon. Had Toshiba used LiPoly cells, your energy density would be more than 20% higher, giving you just under 8 hours per charge. I think if we petition Intel for some 22nm parts, that figure would most certainly go out to 16 hours – good enough if you ask me.

lets just hope this do not make the hardware and software go lazy and any battery gains lost in a new wave of power wasting products…

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