MIT Boffins Build Battery Alternative Out of Cement, Carbon Black, and Water (theregister.com) 78
Long-time Slashdot reader KindMind shares a report from The Register: Researchers at MIT claim to have found a novel new way to store energy using nothing but cement, a bit of water, and powdered carbon black -- a crystalline form of the element. The materials can be cleverly combined to create supercapacitors, which could in turn be used to build power-storing foundations of houses, roadways that could wirelessly charge vehicles, and serve as the foundation of wind turbines and other renewable energy systems -- all while holding a surprising amount of energy, the team claims. According to a paper published in the Proceedings of the National Academy of Sciences, 45 cubic meters of the carbon-black-doped cement could have enough capacity to store 10 kilowatt-hours of energy -- roughly the amount an average household uses in a day. A block of cement that size would measure about 3.5 meters per side and, depending on the size of the house, the block could theoretically store all the energy an off-grid home using renewables would need." [...]
Just three percent of the mixture has to be carbon black for the hardened cement to act as a supercapacitor, but the researchers found that a 10 percent carbon black mixture appears to be ideal. Beyond that ratio, the cement becomes less stable -- not something you want in a building or foundation. The team notes that non-structural use could allow higher concentrations of carbon black, and thus higher energy storage capacity. The team has only built a tiny one-volt test platform using its carbon black mix, but has plans to scale up to supercapacitors the same size as a 12-volt automobile battery -- and eventually to the 45 cubic meter block. Along with being used for energy storage, the mix could also be used to provide heat -- by applying electricity to the conductive carbon network encased in the cement, MIT noted.
As Science magazine puts it, "Tesla's Powerwall, a boxy, wall-mounted, lithium-ion battery, can power your home for half a day or so. But what if your home was the battery?"
Just three percent of the mixture has to be carbon black for the hardened cement to act as a supercapacitor, but the researchers found that a 10 percent carbon black mixture appears to be ideal. Beyond that ratio, the cement becomes less stable -- not something you want in a building or foundation. The team notes that non-structural use could allow higher concentrations of carbon black, and thus higher energy storage capacity. The team has only built a tiny one-volt test platform using its carbon black mix, but has plans to scale up to supercapacitors the same size as a 12-volt automobile battery -- and eventually to the 45 cubic meter block. Along with being used for energy storage, the mix could also be used to provide heat -- by applying electricity to the conductive carbon network encased in the cement, MIT noted.
As Science magazine puts it, "Tesla's Powerwall, a boxy, wall-mounted, lithium-ion battery, can power your home for half a day or so. But what if your home was the battery?"
Next level (Score:5, Funny)
Can you combine this with the ancient Roman recipe for self-healing waterproof concrete?
Because it then becomes a great building material for slab foundations or basements. And hell, 3D print the thing and build the whole home that way - one giant super capacitor / heating system.
The future is very weird sometimes.
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Until you accidentally touch the wall...
Re:Next level (Score:5, Interesting)
Taking the concept seriously for a moment... you could use this capacitive concrete as a core and sheath it in standard concrete. To charge or discharge would require creating deliberate access ports through that exterior sheathing.
Then there's the issue of controlling it all. Maybe you'd do something like divide it up into segments bridged with circuit breakers to ensure the entire building couldn't short and rapidly discharge due to damage at a single point. Since this stuff can also be used for heating, you might want to have segments that have ducts or pipes passing through to heat air or water.
Turning a bulk power system into your building structure would mean a lot of space saving - at least compared to having a giant block of the stuff within the living area.
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Of course you are completely right. Every new technology initially looks like it will open a tunnel straight to hell. Until it doesn't. In the 1800s people thought they would die from inner bleedings going 20 mph with those new trains.
This new concrete could turn out a pretty cool technology but of course there are some issues to be thought about. Encasing, safety in general and also recycling should not (any probably will not) be an afterthought.
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Every new technology IS a tunnel straight to hell. Then you create all sort of small technologies around it to make it safe.
An Interesting Aside (Score:2)
Those 19th C. people talking about how dangerous 20mph is to the human body were misinterpreting a paper that was a first approximation of what would happen to a human body if it came to a sudden stop from those speeds. In fact, that paper was rather correct. Coming to a sudden stop from 25mph is effectively the same as hitting the ground after dropping from two stories up. It is in fact enough force to overcome the tensile strength of the connective tissue holding your organs in place. But the "sudden stop
45 cubic meters? (Score:4, Insightful)
That's huge: imagine a cube 11 ft on a side. And 10kWh may be the average in the UK, but it's not much at all. The UK is pushing people to dump gas and install air-source heat pumps which will dramatically increase electricity use.
Put this in the category of: that's interesting, but not useful until there is a huge improvement in performance.
Re:45 cubic meters? (Score:5, Insightful)
That's huge: imagine a cube 11 ft on a side
That's a cube with a side length of ~3.5 meters. Given that there are ~28000 households in the UK, and that an olympic swimming pool is 2500 cubic meters, the end result is that we would need the equivalent of ~504000 olympic swimming pools of this new cement.
That's a lot of cement. The main question I have is how much are the CO2 emissions needed to manufacture that cement, knowing that cement production already generates a lot of CO2 (contributes for 7% of the total, more than aviation for instance). I didn't find that information in the paper, but I may have missed it.
Re:45 cubic meters? (Score:5, Informative)
I think there are more than 28,000 households in the UK, because otherwise, there are about 2,400 people per household. Given the average size of a British flat, that seems excessive. I think you meant 28 million, which seems more reasonable.
As much as Slashdot loves using Olympic swimming pools for volumetric comparisons, I feel that it is sometimes more useful to look at national consumption rates instead. The UK used about 15 million metric tons of cement in 2021. The most commonly used amount of cement was 0.80 g/cubic cm, so for 45 cubic meters, that would be 36 metric tons of cement for one of these batteries. To retrofit every household with one of these batteries would be about a billion metric tons of cement, or about 67 years of cement production. Ouch. But maybe it wouldn't make such a big dent if applied only to new builds, or maybe it would make more sense for grid-scale storage. Perhaps they'll find improvements over time that allow them to use less environmentally expensive materials, too.
They acknowledge the environmental cost of cement production, but believe that, tied with renewable energy sources, the production would be offset over time. I don't see anything in the article about the normal factors involved in recharging the battery including loss of capacity over number of recharges, though maybe that will be explored in future papers.
Re:45 cubic meters? (Score:5, Informative)
Note that they called it a (super)capacitor, not a battery. I think the problems with capacitors are different from those with batteries. E.g. the charge tends to leak away more quickly. OTOH, you can charge (and discharge) them faster.
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So, for putting in industry, recharge sites, and yes, even in homes with basements, this would make sense. It will at least deal nicely with smoothing out supply/demand issues.
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One the things that makes caps "super" is having a low leakage rate. Otherwise they are just normal high capacity capacitors. Certainly in the timescales that a home use one would cover, basically 24 hours max, self discharge is not going to be a major issue. The main use would be gathering excess solar energy during the day, and cheap grid energy at night.
I don't think they are suggesting that every house be retrofitted with one of these things, but for example one could be use as the foundation of a new h
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Pricing could be something of an issue. They mention 0.18 g/cc of carbon black getting used at the high end, so about 8.1 metric tons of carbon black. Pricing seems to be about $1.75/kg in Europe, so (not factoring in demand changes) a little over $14,000 of CB, plus whatever the 36 tons of concrete costs. But if it doesn't leak or degrade significantly, maybe that will be worth it over time.
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To retrofit every household with one of these batteries would be about a billion metric tons of cement, or about 67 years of cement production. Ouch. But maybe it wouldn't make such a big dent if applied only to new builds, or maybe it would make more sense for grid-scale storage
Indeed, house turnover here is low. We like to hold on to them for a while rather than rebuild. My house is 109 years old which is regarded as utterly unremarkable for its age. The older Victorian stock is considered pretty normal.
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Even in the US, there is a lot of older housing stock. The median house age here is 39 years, and it's not all that uncommon for houses to be 80+ years old. If you look at the DIY subreddits, there are more than a few people working on 100+ year old houses.
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As a Londoner, it's possible that my view is a bit skewed. Turns out London has on average older housing than most of the rest of the country. With that said it's also got a lot more of it and this graph isn't weighted by population:
https://www.ons.gov.uk/peoplep... [ons.gov.uk]
Looks like ~22% of the houses are pre 1900 round here and a whopping ~38% are older than 93 years old.
I like old houses. Being a bit of a caveman apparently, one thing I particularly like is how the temperature drops fast in the evening/at night
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The median age of houses in Washington, DC, is 80 years, and the median in all of the state of New York (even with NYC growing over the last half-century) is 62 years. For the long-established cities, there be a lot of old houses.
On the other hand, there are quiet communities like that. My wife's family has a lake cabin an hour from the nearest decent size community and two hours from the nearest real city, where the core of the cabin was built around 1920. Her grandfather extended it in I think the 1950s,
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You need to re-state that in units of Libraries of Congress.
Re:45 cubic meters? (Score:5, Informative)
The only question would be the additional cost to turn it into a battery and is it structural enough to be used as building material.
Then can I get the kind of workers that normally lay concrete to build this battery. I barely trust qualified electricians I would not trust these workers and that is the real problem.
BTW carbon battery tech is old replacing the zinc with cement is novel https://en.wikipedia.org/wiki/... [wikipedia.org]–carbon_battery
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>the small pool had 13.5 cubic meters.
build the swimming pool casing with a capacitor. What could possibly go wrong???
hawk
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Yeah, 10 kWh is a joke. My commuter e-bike as 1 kWh, two people couldn't do laundry with 10 kWh.
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Re:45 cubic meters? (Score:5, Funny)
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A washing machine uses less than 1kWh per hour, depends basically on how hot you wash and if you have an hot water intake or not.
With 10kWh you can wash 10 hours long. That is quite a bit of laundry.
Re:45 cubic meters? (Score:5, Informative)
For reference the Passiv Haus standard requires that the building consume no more than 4.5kWh per day for heating and cooling, to maintain a pleasant internal temperature. So in a well designed house it's over 2 days of HVAC.
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I don't really think you could use it in the same way. Concrete it usually just slopped into place in forms, but if they want this to be a capacitor you're going to need to worry about conduction paths. This probably means 3d printing with reasonably fine controls over where the carbon is laid down.
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I'd do it .. I'd make it in the form factor of a pyramid.
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Fixing that for you:
10 kilowatt-hours of energy -- roughly the amount an average^H^H^H^H^H^H^H^Hamerican household uses in a day.
And 10kWh may be the average in the UK, but it's not much at all. Most likely not even half.
Put this in the category of: that's interesting, but not useful until there is a huge improvement in performance.
It actually is super useful, as we have concrete constructions everywhere. And e.g. a wind mill put up on such a base, can just store the surplus on site.
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It's not useful, period. Obviously these MIT boffins don't know shit about foundations. From their paper, they cut the cement in thin sheets and put electrolyte in between it. Not sure if you ever poured a foundation, but the goal is not to immediately reduce the tensile strengths of concrete by cutting it up with a laser and pouring a caustic liquid in the ground.
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That's huge: imagine a cube 11 ft on a side.
Yep, and cement is one of the least carbon-neutral things imaginable.
Currently: 8% of global CO2 emissions come from cement, that's three times more than aviation.
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"enough capacity to store 10 kilowatt-hours of energy -- roughly the amount an average household uses in a day. "
What tropical paradise is that? My all-electric house with two people uses 20 kWh a day in the summer and 60 in the winter. One particularly cold and windy month it used 80 kWh/day.
And yes I have a heat pump. The house is 1400 sq ft, so not an Al Gore rated mansion either.
Re: 45 cubic meters? (Score:2)
Okâ(TM)d letâ(TM)s consider it. Thatâ(TM)s 1331 ft^3.
Letâ(TM)s assume they can make this a foot thick. Thatâ(TM)s a top surface of 1331 ft^2. My house is 1670. Again, assuming they can make one foot thick, I can see this being used as a foundation for houses
Not gonna fly (Score:4, Funny)
Literally. No electric airplanes with this much cement.
Re:Not gonna fly (Score:4, Funny)
Literally. No electric airplanes with this much cement.
There are no concrete plans for that at this time. :-)
Would be great (Score:2)
Would be great if they can scale this up. I suspect they have made some hockey-puck sized prototypes or maybe a little bigger. They have "plans to scale up to supercapacitors the same size as a 12-volt automobile battery" after several months, I will be more interested if they can do that.
10kW a day? Where? (Score:1)
Re: 10kW a day? Where? (Score:2)
You meant kWh.
instantaneous discharge when wet? (Score:4, Interesting)
Re: instantaneous discharge when wet? (Score:3, Interesting)
And what about running rebar or drain pipe through the stuff. Tough to build foundations without rebar.
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From the sound of it, you would probably break it up into cells with a cheap insulator. The low voltage means no arcing. You could also put on a top layer of normal concrete, over a membrane perhaps.
You'll ned more than you think (Score:2)
"45 cubic meters of the carbon-black-doped cement could have enough capacity to store 10 kilowatt-hours of energy -- roughly the amount an average household uses in a day."
Where? US average is 30kWh.
Cool regardless.
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Yup The 2023 annual US average is 10,632 kWh, but it varies slightly depending on location. Divided by 365 is 29.1kWh.
https://www.energybot.com/blog... [energybot.com]
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"45 cubic meters of the carbon-black-doped cement could have enough capacity to store 10 kilowatt-hours of energy
Cool
Except that producing 1 cubic meter of concrete creates over 400kg of CO2.
Simple, but does it last? (Score:1)
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The paper states that they add a bit of excess water that forms micro-pores, allowing charge transfer. It's cold weather performance is unknown, but probably impared when below freezing.
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Increased porosity would increase damage from freeze thaw cycles any way.
You'd want to use this with below slab insulation, the slab would never freeze.
I hear it's also a room temperature superconductor (Score:3)
This... (Score:2)
Um...45 cu m = 200 tons of battery (Score:3)
Haven't had to get an estimate for this exact sort of problem, but I'm fairly certain that the excavation and site prep necessary to install a 200 ton brick is going to cost more than a 10 kWh lithium battery.
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Haven't had to get an estimate for this exact sort of problem, but I'm fairly certain that the excavation and site prep necessary to install a 200 ton brick is going to cost more than a 10 kWh lithium battery.
The cost of lithium isn't going to be static. Should demand for lithium batteries spike then so would the price for lithium. The prices for cement and carbon black would also go up if there's a large demand for these capacitors but there is a much larger existing market for cement and carbon to draw from to mitigate pricing spikes.
I read somewhere that it takes ten years to open up a new mine so it is not like we'd see price increases bring a rapid increase in supply. There's already considerable price p
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Haven't had to get an estimate for this exact sort of problem, but I'm fairly certain that the excavation and site prep necessary to install a 200 ton brick is going to cost more than a 10 kWh lithium battery.
If you are already doing a concrete foundation with easily that amount of concrete its only the additional cost to turn it into a battery likely less than a lithium battery but there are many other issues that would be of concern the workers that are doing first the lifespan of the batteryIt would be rubbish if you had to rip up the house when the battery needed changing
10 KwH / Day Household Useage? (Score:2)
Disregarding everything else, back in Virginia my electric was about 750 KwH per month with my Geothermal system simply heating. Here in Texas, its closer to 950 KwH per month for my heat pump fighting the furnace of 105 degrees every day. Neither of those numbers equals 10 KwH per day. Just sayin'...
Building new place. The insulation installation is going to be... expensive... but I can pay for that over 30 years, rather than the stupendous electric bills every month if I didn't buy the insulation.
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Clearly you need better insulation. And probably should use solar panels to shade your roof with air circulation between the two.
But their estimate is rather absurdly low.
Cost, efficiency? (Score:3)
The concrete battery seems at least 10X more expensive and about 1000X as heavy as the conventional solution.
What is the efficiency, power density, and cycle life?
As others have said, 10KWH is pretty low as well. I have about 35 KWH of battery for my condo - enough to last about a day or so of normal usage.
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If you're going to pour the concrete anyway, how expensive is it then?
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Energy storage makes everything cheaper. (Score:2)
In every article on some new battery or capacitor they make a big deal about how this would make renewable energy cheaper. That's true, but then energy storage would make most any form of electric generation cheaper.
Large steam power plants, like coal power plants, don't react well to changing demand. Once these big steam engines get running they like to stay where they are on power output. Utilities put up with this limitation because steam power plants are cheap to run. To manage the changing demand t
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Curious why you omit thorium
I omitted thorium because I didn't want replies about how thorium as an energy source is an untested technology that would take years, if not decades, to bring to commercial scale. It seems I can't win on this. If I mention thorium then I'm a fool for thinking that we'd get thorium power plants in time to make a difference on CO2 emissions. If I don't mention thorium then I'm buying into the foolishness that thorium has nothing to contribute.
Here's where I stand, we should use the technologies we have to
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and perhaps U-234 which is found in spent fuel rods but with most reactors today is considered a "neutron poison".
That is wrong. U-234 is no neutron poison, it captures slow neutrones and breeds U-235, which is uh oh, reactor fuel.
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Large steam power plants, like coal power plants, don't react well to changing demand.
That is nonsense. No longer true since roughly 100 years.
Once these big steam engines get running they like to stay where they are on power output.
For a base load plant, yes. Because it is intentionally build to do that.
Not correct for a load following plant.
Utilities put up with this limitation because steam power plants are cheap to run. To manage the changing demand through the day the utilities will throttle other pow
WTF is a Boffin? (Score:1)
British slang for Scientist. https://en.wikipedia.org/wiki/Boffin [wikipedia.org]
Not to be confused with Boffing someone. https://www.merriam-webster.com/dictionary/boffing [merriam-webster.com]
This why I don't watch British television. I need British to English subtitles.
Re: WTF is a Boffin? (Score:2)
not competitive , just a curiosity (Score:2)
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There are so many battery types out there there needs to be a chart like this following them like the one for solar here:
https://www.nrel.gov/pv/cell-e... [nrel.gov]
Ideally the line colour for each tech' could go from red to green corresponding to how far the tech has progressed from research paper through to mass produced products.
dimensions (Score:2)
Upon constructing the prototype in a pit behind the Sttatton Student Center, the scientists charged the black monolith . The transformers produced a painful high-pitched noise for about a minute. Then all the laptops and phones within 500 meters suddenly blanked out, and the screens then showed the following message:
ALL THESE YARDS
ARE YOURS EXCEPT
HARVARD
ATTEMPT NO
LANDING THERE
Not _too_ expensive either (Score:2)
I see carbon black selling for about 25 bucks for 500 grams. I wonder how much that would add up to, with a 10% mix? Those are artists' rates too, I suspect; might be cheaper in industrial quantities.
What about aggregate? (Score:2)
TFA seems to conflate cement and concrete. Nobody is going to make a 200 ton block of cement, because the main point of the cement is to bind aggregate. Will these carbon fractal wires still form when mixed with gravel?
It doesn't need to be structural (Score:1)
Too much money (Score:2)
I scanned the page for the word "dollar" and nobody seems to have gone there, so to point out the obvious:
* Concrete runs over $200/cu.m. so 45 cu.m. is $9000.
* Alas, "concrete" is about 25% "cement" and 75% "rocks", and rocks aren't much of the $200.
* If you were to make cubic metres of pure cement, with no aggregate (nobody in construction does) then the 45cu.m. would probably run you $35,000
* Whatever turns it into a battery would add to that, in manufacture cost if not materials, so it's hard to cost th
Humidity and electrical leakage (Score:2)
Re: Humidity and electrical leakage (Score:1)
Thomasonâ(TM)s Water Seal is good stuff. Would mitigate.
Round trip efficiency and self-discharge rate? (Score:2)
What's the round-trip efficiency and self-discharge rate?
The material won't be too useful if it heats a house more than the power delivered can air-condition it.
A Glaring Error (Score:2)
The average American household uses ~30kWh of energy a day. European countries range from ~20-25kWh a day. Only if you include all the households using effectively 0kWh/day in the world could you get an average of 10kWh/day. This seems like a small error but it's very glaring. It means you can't trust anything else said in this article.