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Scientists Deliver a Longer-Lasting Lithium-Oxygen Battery (technologyreview.com)
Packing more energy into batteries is the key to delivering electric cars with longer range, smartphones that can last days -- and cheaper electronic products all around. Lithium-oxygen batteries represent one of the more promising paths toward that end. From a report: They could boost energy density by an order of magnitude above conventional lithium-ion batteries -- in theory, at least. In a paper published this week in Science journal, researchers at the University of Waterloo identified ways of addressing some of the major hurdles to converting that potential into commercial reality.
A critical problem has been that as a lithium-oxygen battery discharges, oxygen is converted into superoxide and then lithium peroxide, reactive compounds that corrode the battery's components over time. That, in turn, limits its recharging ability -- and any real-world utility. To get around the problem, researchers switched from a carbon cathode to one made of nickel oxide and supported by a stainless steel mesh. They also used molten salt for the electrolyte -- the part of the battery that allows positively charged ions to move between the electrodes -- and raised the battery's operating temperature to 150C. Those steps made it possible to achieve about three times the number of charging cycles as earlier lithium-oxygen efforts. The researchers also managed to increase the energy per unit of mass by more than 50 percent.
A critical problem has been that as a lithium-oxygen battery discharges, oxygen is converted into superoxide and then lithium peroxide, reactive compounds that corrode the battery's components over time. That, in turn, limits its recharging ability -- and any real-world utility. To get around the problem, researchers switched from a carbon cathode to one made of nickel oxide and supported by a stainless steel mesh. They also used molten salt for the electrolyte -- the part of the battery that allows positively charged ions to move between the electrodes -- and raised the battery's operating temperature to 150C. Those steps made it possible to achieve about three times the number of charging cycles as earlier lithium-oxygen efforts. The researchers also managed to increase the energy per unit of mass by more than 50 percent.
You can now also heat your house with it while discharging!
I have this sneaking suspicious that news about battery improvements is a circle of different press releases, such that they re-publish the same article every five years or so before moving further around the circle.
The whole stainless steel mesh thing sounds just familiar enough I'm pretty sure they gave the game away.
Oh battery scientists, you are so clever! They are probably all laughing at us from a tropical shore, drinks in hand and diesel generators happily powering a boombox.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Because with a 150C battery in it, you don't dare pick it up to use it.
It's another basic science press release! A molten salt battery, Yet somehow it runs at 150C, so salt doesn't mean NaCl, which melts at 801 degrees centegrade. And it's corrosive and eats itself. OK, lead-acid batteries are too, but there's some significant technology to get past, and this is still just a research project. Also, I'm wondering what heating up the whole battery to 150 C to start your car will look like, and what sort of battery you will need to do that. Obviously not the same battery.
Wake me up when I can buy one off the shelf, OK?
Bruce Perens.
If that's the cost of 10x the range people would gladly do it. If it makes you feel better you can "only" charge it for 8 hours and get a mere 8x the range. This is a good problem to have.
We've found that batteries made for the Chinese internal market frequently have a lower capacity than those made for the Korean and US markets. Has to do with how they're made. Be aware of this.
That said, also be aware of the operating ranges and any physical defects.
-- Tigger warning: This post may contain tiggers! --
I know science is hard, but it's astounding how many "new and improved battery" stories that we see, and how few of them end up being useful.
it would be really interesting to do some statistics and see how many of these things have actually resulted in improvements to batteries that you can actually buy.
my guess is that he number is really low, maybe even 0.
it's kind of a amazing.
Absolute statements are never true
Why would a car manufacturer keep a battery of the same size with 10x the density, knowing that charging that battery would be a problem?
They could always just make a battery pack that gives X range, and keep the charging the same for the value of X, but with a much smaller pack (less mass)
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
Well yeah, if you want to charge from empty to full overnight you would have to fast charge. But that would not usually be the case, would it? If you have 10x the energy, thus 10x the range, you could go 2500 miles on a charge. Nobody is doing that daily. So slow charge to 10% the first night, use half of that charge during the day, after the next night you are at 15%. In 20 days you will be at 100%, then you just need to keep it 'topped up'.
No, I think he's actually right this time. Within the last few years I remember hearing separately about both the "lithium-oxygen" thing and the "[something unexpected] mesh cathode" thing. Long enough ago in both cases that it's suspicious this is being reported on again as though it's brand new now. Who knows though, maybe they did really have another breakthrough in feasibility? I didn't read the article.
Or, thinking like a manufacturer, put 1/8th the amount of batteries in the vehicle.
Not necessarily. Battery charging rate depends on a number of things, including limits on charging rate to maximize battery life.
Tesla's supercharging stations use proprietary systems to deliver "up to" 120KWs to the car. At that rate it should completely charge a completely discharged 90 kWh battery in 45 minutes. But I don't think this happens, because to preserve the battery rate of energy deliver drops as you get closer to topped up. Given that's the case, shoving 90kWh of energy into a 180 kWh battery should be faster than shoving 90kWh into a 90kWh battery.
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Providing 1,200 kW (ten Tesla superchargers) over any sort of human-manipulatable cable would likely be infeasible. You'd either have to use an insane voltage, requiring even thicker jackets to reduce the safety risk, or use an insane amperage, resulting in a conductor diameter measured in inches. And imagine each charge station drawing as much power as the entire supercharger does now. The existing electrical infrastructure probably can't provide that much power in most places.
Realistically, if we got a 10x increase in storage, I would expect the car companies to divide the pack into sub-packs and charge them sequentially, resulting in a 10x increase in charge times (well, probably more like 6x to 8x, because you could probably start fast-charging the next group of cells long before the first group gets completely full). If we're lucky, they might provide one or two or more charge cords per car to offset some of the difference in some places, where the infrastructure permits.
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