Slashdot Mirror
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.
Let's hope this isn't patented, so that anyone can use the research. Universities have a habit of taking federal funds, then patenting the research that those funds produce. This research was partly funded by the Air Force Office of Scientific Research. Congress should repeal the Bayh-Dole Act and require that any innovations from federally funded research be placed in the public domain.
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.
At 943 WH/kg and 1322 W/kg, this is really quite good. According to wikipedia, this is 4x "traditional" Li-ion density in terms of storage and decent in terms of charge/discharge rate.
I know they tested 500 cycles. Get to 1000 and it is practical. Get to 5000 and it owns the market.
So any /.er knows battery "breakthroughs" are once a month or more on average (or so it seems). But most, or so far one supposes all, of them have major problems. A battery needs to hit high power density, IE how much power it can deliver over time. High energy density/specific energy, IE how much energy it can store per liter and per kilogram. It needs to be able to last over a long amount of charge/discharge cycles, because if your battery loses too much energy/shorts/explodes after a few charges then it's useless. And it needs to be cheap to make.
Well, surprise, but somehow this one seems to be the announcement that, could, hit all of those points. The reported numbers are several times the current best for li-on power density, energy density (assumedly for both volume and weight), lasts a lot of charge and discharge cycles, and doesn't require some exotic rare earth material to make. Assuming the actual creation process isn't exotic or complex, IE can be economically scaled, this could actually be the coming of the affordable electric car/smartphone battery that actually lasts all day/etc. that's been promised for a while now. Here's fuckin hoping.
Over the last decade batteries have improved dramatically in capacity, reliability, charging speed, and (especially) cost. This is a result of the very breakthroughs that you so flippantly denigrate.
If you aren't interested in reading about leading edge research, then what are you doing on Slashdot?
Welcome to the world of research! The gap between physical possibilities and economical viability is large, but without sufficient breakthroughs on physical possibilities we will never find one that is economically viable.So, regardless of the chances being slim that we will reap the benefits of all these breakthroughs anytime soon, I am still happy to see such breakthroughs happen.
Not only that, but reading that they used asphalt for this makes me think I'm driving on the biggest darn battery everyday (I know, it's not true... still...;)
He is here to post, not read anything he posts about.
That's some pretty hefty hyperbole. It got that reputation from the past history at Sudbury, but today Sudbury is used as an exemplary case study of reducing environmental pollution from mining and remediating damaged landscapes.
"If there was an antonym to 'Elon Musk', it would be 'Richard Branson'."
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/...
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.
---
According to the latest ruleset, this post should be modded as Vorpal Flamebait +5.