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Rice University Adds Asphalt To Speed Lithium Metal Battery Charging By 20 Times (nextbigfuture.com)
schwit1 writes: The Rice lab of chemist James Tour developed anodes comprising porous carbon made from asphalt that showed exceptional stability after more than 500 charge-discharge cycles. A high-current density of 20 milliamps per square centimeter demonstrated the material's promise for use in rapid charge and discharge devices that require high-power density. The Tour lab previously used a derivative of asphalt -- specifically, untreated gilsonite, the same type used for the battery -- to capture greenhouse gases from natural gas. This time, the researchers mixed asphalt with conductive graphene nanoribbons and coated the composite with lithium metal through electrochemical deposition. The lab combined the anode with a sulfurized-carbon cathode to make full batteries for testing. The batteries showed a high-power density of 1,322 watts per kilogram and high-energy density of 943 watt-hours per kilogram. Testing revealed another significant benefit: The carbon mitigated the formation of lithium dendrites. These mossy deposits invade a battery's electrolyte. If they extend far enough, they short-circuit the anode and cathode and can cause the battery to fail, catch fire or explode. But the asphalt-derived carbon prevents any dendrite formation.
"The capacity of these batteries is enormous, but what is equally remarkable is that we can bring them from zero charge to full charge in five minutes, rather than the typical two hours or more needed with other batteries," Tour said. "While the capacity between the former and this new battery is similar, approaching the theoretical limit of lithium metal, the new asphalt-derived carbon can take up more lithium metal per unit area, and it is much simpler and cheaper to make. There is no chemical vapor deposition step, no e-beam deposition step and no need to grow nanotubes from graphene, so manufacturing is greatly simplified." The findings have been published in the journal ACS Nano.
"The capacity of these batteries is enormous, but what is equally remarkable is that we can bring them from zero charge to full charge in five minutes, rather than the typical two hours or more needed with other batteries," Tour said. "While the capacity between the former and this new battery is similar, approaching the theoretical limit of lithium metal, the new asphalt-derived carbon can take up more lithium metal per unit area, and it is much simpler and cheaper to make. There is no chemical vapor deposition step, no e-beam deposition step and no need to grow nanotubes from graphene, so manufacturing is greatly simplified." The findings have been published in the journal ACS Nano.
Battery chemistry is a hot topic and pretty much anything that shows promise is being researched by someone somewhere.
Ni-Fe
Ni-Zn
and those results are just for 2016-2017, and I didn't search for synonyms "Nickel", "Iron", "Zinc", "cell" (instead of "battery".)
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
Come on-- even the header says it prevents fire and explosions.
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
2017 already, man. Learn to not feed the trolls or GTFO.
Meanwhile, cell phone batteries keep shrinking while their amp hours keep growing.
No, any given announcement isn't likely to ultimately play out. But some fraction of them do, and they change the world behind the scenes. The classic example is silicon anodes, which were the subject of big news stories on Slashdot years ago, then there was nothing.... but today they're commonly used in high-capacity li-ions.
As for this specific research: I read the study, and I have to admit, it's pretty impressive. One of the big things is that not only is the ion mobility high, but the coulombic efficiency is also very high (95-96% at high charge rates, 99% at low rates). If you want fast charging, having both is critical; otherwise, you'll never remove all of the waste heat at a fast enough rate.
After having read the paper, I have to add some caveats about this:
This is for the active materials only, not for whole cells, and only at low power density. First, the cell capacity is quite sensitive to how fast you charge it - if you charge it fast, the peak capacity is significantly reduced. That said, it's not a permanent difference; if the next time you charge it's a slow charge you go right back to the higher capacity. Secondly, when you include the inactive materials, they show about 450Wh/kg at low charge rates, and around 300Wh/kg at high charge rates. That said, it's still nice - and further refinement could probably reduce the inactive mass.
The capacity loss over 500 cycles - perhaps I'm not reading clearly, as I'm not seeing where that figure is given out. One of their graphs appears to show something like 10-15% loss over 130 cycles at 0,5C charge rate. It's hard to say how the curve will continue from there. A caveat is worth adding, in that the higher your maximum capacity, the fewer cycles you actually need, since for a given task you put fewer cycles per unit time on a higher capacity battery than a smaller capacity battery.
I see nothing about accelerated aging tests to see if there's any particular aging effect. Then again, I don't expect much of one, given their chemistry.
As for manufacture, it's a simple process, and requires no (relatively) expensive mined materials (e.g. no cobalt or the like). That said, one of their components - graphene nanoribbons - I have no clue what the current manufacturing costs are, nor what the potential is to bring them down in mass production. In theory, for something that's pure carbon, the cost should be able to go way down, since basic organic feedstocks are dirt cheap compared to most inorganic feedstocks. But that doesn't mean we've gotten it down that much at this point.
Just my takes from reading the paper :)
"If there was an antonym to 'Elon Musk', it would be 'Richard Branson'."
Gilsonite might technically be Asphalt by definition,but it's a unique natural bitumen composed of a mix of light but solid hydrocarbons. It only occurs in one spot on the planet (the Uinta Basin in Utah).
It's believed to have been created when a few million years ago a geothermal event warmed up the Uintah oil shale (the same stuff they frack) and liquefied a bunch of the hydrocarbons into a slurry that then oozed up the cracks and solidified. It's a solid, actually looks quite a bit like obsidian (glossy and black) but is super light weight and obviously not glass. It's so light weight they mine it by hand with air hammers and use vacuums to collect it and bring it to the surface.
https://en.wikipedia.org/wiki/...
A couple of points to consider on this (I am a prof at a University, but used to work in industry):
1 - in my field at least (biomedical research), industry won't touch something without patents, which means it won't make it to market. It just costs too much to do all the safety & efficacy testing etc for it to make economic sense without a patent. The appropriateness of pharma pricing is a separate discussion, but the reality of the situation is if you want patients to benefit, you need industry to get on board in pretty much all but a few edge cases.
2 - conservatively, I would be making twice as much (probably more, possibly a lot more) in industry, with less stress about funding my research, and there is a lot more scope for a high-level career trajectory as well. The potential to earn royalties on inventions I develop is an important counterbalance to this (usually split between the Uni, myself, and my trainees, although YMMV depending on country - my understanding is in the US faculty don't get direct royalty payments but make up the difference by consulting for the licensee). If you're going to cut off that income stream, and you still want to recruit the kinds of people who can come up with these inventions, you will need to find a lot more money to bump up salaries.
I reckon there were fan-cooled chargers that would do it in 30 minutes back then too.
Recharge efficiency and heat dissipation are two areas that these batteries specifically improve.
Smart phones and laptops have already benefited from faster recharging---as recently as 2-3 years ago. They can't just throw better cooling into the mix, so they rely on improvements like this.
But in the last ten years, the technology, capacity, size and charge times have barely changed.
The improvement of ~20% is much less than what we get in the microprocessor industry, but every bit helps.
And as far are charge times are concerned--- that is straight up wrong. You can now charge a phone from ~25% to ~75% in about 15 minutes, and that was not possible a decade ago. Fast-charging has quickly but quietly become the norm.
The ability to squeeze more energy into a smaller volume is what makes modern smart phones possible at all. Android could not exist if we still used 1980s-era battery tech.
There are other factors. LiPo batteries are about 1/5 lighter than traditional lithium ion batteries (of equal capacity). This is hugely advantageous for drones and other markets where weight really matters. And everyone likes lighter laptops/phones, even if the difference is not critical from a design standpoint.
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According to the latest ruleset, this post should be modded as Vorpal Flamebait +5.