Tuesday, October 24, 2017

Yet Another Interesting Tweak for Lithium Batteries

Lithium batteries are almost a regular series around here; a quick search of the phrase "lithium battery" or "lithium batteries" returns well over a dozen posts on the subject.  This latest update comes from Design News (not the first battery post from them) author Elizabeth Montalbano on the discovery that adding asphalt to Lithium Ion batteries not only increased energy storage but allowed the batteries to be charged faster.
Researchers in the lab of James Tour, a Rice professor and chemist, have developed anodes that comprise porous carbon made from asphalt that showed significant stability even after more than 500 charge-recharge cycles, he said.

“They are very easy to make and have very high capacity—about 10 times more capacity than present battery anodes,” Tour told Design News . “Moreover, they charge in five minutes rather than two to four hours.”
Back in May, I quoted Charles Murray from Design News, saying,
While battery makers desperately try to figure out how to reach a specific energy of 450 Wh/kg (Watt-hours per kilogram), gasoline already offers 12,000 Wh/kg.
That problem still remains, although the Dr. Tour's batteries have more than doubled their specific energy to 943 Wh/kg from the cited 450 Wh/kg.  Now instead of having a 26.7:1 advantage, gasoline has a 12.7:1 advantage.  That has to be able to improve an EV's range (Electric Vehicle), but there are no practical numbers to base conclusions on. 
(Scanning electron microscope images show an anode of asphalt, graphene nanoribbons, and lithium (left) and the same material without lithium (right). The material was developed at Rice University and shows promise for high-capacity lithium batteries that charge 20 times faster than commercial lithium-ion batteries. (Image source: The Tour Group, Rice University))

Left for last in the DN article is the second most important aspect of this technique, which overcomes a common issue with Li-Ion batteries, their rather gauche habit of catching fire.
Testing also showed another improvement that the carbon brought to the batteries in that it mitigated the formation of lithium dendrites, or mossy deposits that can invade a battery’s electrolyte, researchers said. It’s these dendrites that can make batteries fail, catch fire, or explode because they can short-circuit the anode and cathode.
Recharging faster is very important for cars, as demonstrated in the recent evacuation of Florida for Hurricane Irma.  Twice the capacity may be even more important, since you'll get farther on a charge (Tesla Motors was reported to have issued an Over The Air software upgrade to some Teslas in the state to remove some software restrictions on the battery and increase their range).  Doing both of those while being a safer battery sounds like a real good change for the industry.  Before you ask, there's no mention of a patent or how Rice University manages such things.


7 comments:

  1. This comment has been removed by the author.

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    2. 24-48X the recharge speed?

      Faster recharge is nice, and kudos to Rice U. researchers for that material innovation.

      The real problem is getting them to hold more storage capacity, not just recharge faster, nice though that is.

      A car that will only go 50 miles is still just a car that will only go 50 miles, i.e great for the mailman's delivery jeep, but not so bitchin' for a commuter with a 60 mi. trip one-way, daily.

      When they can suddenly jump Li batteries to giving you 500 miles useful range (or even 300), they're onto something. Until then, it's just a fast-charging novelty vehicle.

      But this and future improvements bear close watching.

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    3. Doubling the existing energy density they can get up to 943 Watt hours/kg of battery is a big plus here, too. Unfortunately, gasoline and diesel still have a very big advantage here and that's going to take time if it's ever surmountable.

      Batteries have to take their oxidizer with them; internal combustion engines get it for free from the environment. There are Zinc-air batteries that get their Oxygen from the air; they're just hearing aid size and don't scale up well.

      Unless they have a gasoline car and an electric car, Floridians, Texans and anyone else that may have to suddenly drive a few hundred miles to get away from a storm are really stuck. The infrastructure just isn't there so that energy density is critical, not academic.

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    4. Ah, but for many of our "leaders" today, that last paragraph is not a problem. It's a feature! Less Deplorables makes their lives easier...

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  2. They have been promising better batteries for decades and indeed they have better batteries but they cost your first born and all your assets to own. The best thing to improve batteries in the past 50 years is not even about batteries! It is LEDs

    Batteries, all batteries come in two versions: 1. Two expensive no matter how good they might be. 2. Expensive but inadequate.

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  3. When an industry becomes ate up with corporate grifters hiding behind the skirts of .gov lawwyers, a work around needs to happen.

    One example is the open source hardware/ software movement. Another is kit planes. When a personal aircraft is $600k, people just build their own for $60k, whose systems evolve much faster than certificated aircraft.

    If you home build an electric electric car kit (hopefully open source) you could get away from the $2800 headlights and the 27 airbags of modern insurance claim disposable debt-barges.

    Next, you put a inverter generator in the trunk or pickup bed and you have unlimited range, a cheap disposable engine, and total maintainability, like a Cuban 1953 Chevy. Yet is still an EPA exempt electric car.

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