[HN Gopher] Researchers have come up with a new way to store ele...
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Researchers have come up with a new way to store electricity in
cement
Author : rmason
Score : 71 points
Date : 2023-08-01 16:44 UTC (6 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| mistrial9 wrote:
| animals and other living things are sensitive to electrical
| charge in a way that we are not -- sounds more like a useful
| industrial application, not something to add to a home.
| LinuxBender wrote:
| I am curious, how does this material react to lightning? Does it
| overcharge and burn up or just stop storing power? One can test
| this with a long enamel coated wire and a model rocket on a
| stormy day to induce a lightning strike.
| shagie wrote:
| (Aside: https://practical.engineering _just_ released a video
| on "Where Does Grounded Electricity Actually Go?" )
| hnisg4y wrote:
| Why does the lightning hit the rocket instead of an antenna
| that's a lower height than the rocket?
|
| Where does energy want to flow, to a higher concentration of
| energy or a lower concentration?
| LinuxBender wrote:
| The lightning hits the enamel wire attached to the rocket and
| flows from positively charged earth to the negatively charged
| cloud. One can find videos of people doing this on youtube
| but I do not have any links handy.
|
| I am more curious what this does to the concrete as it is not
| uncommon for lightning rods to be grounded to a grounding rod
| that is in the building's concrete foundation. I think this
| should be tested prior to mass adoption.
| hnisg4y wrote:
| The grounding wire would just bypass the concrete into the
| earth.
| LinuxBender wrote:
| This is not quite true. All ground rods have resistance
| and are supposed to be tested with a megger and
| documented to be below a specific ohm rating. With time
| they gain resistance and some of that energy will be
| induced into nearby objects, notably anything with
| electrical properties. In this case we are talking about
| a concrete that stores and conducts electricity. A
| lightning strike can be over 1,000,000,000 joules of
| energy. Some of that will be induced into that special
| concrete. Regular concrete can heat up and fracture which
| is _mostly harmless_ but I would like to know what
| happens with this special concrete.
| hnisg4y wrote:
| Well the article says it's made of material that wouldn't
| catch fire if that's what you're specifically Wondering.
|
| Presumably smart people would be insulating the battery
| from an external surge like a lightning strike.
|
| However in practical senses the lightning would go into
| the rest of the ground as the grounding wire would be
| bypassing the concrete.
| barbariangrunge wrote:
| My wife's coworker saw a cow go flying into the air last year
| when lightning struck nearby. Does lightning dissipate
| perfectly harmlessly when something taller is struck nearby?
| Actually curious
| hnisg4y wrote:
| Generally yes because the taller person has lower
| resistance relative to the shorter person. So unless
| they're connected, lightning would pass through the person
| with the least resistance to the ground (easiest way to
| dissipate a voltage difference).
| jjk166 wrote:
| Conveniently, the energy density means that 1 cinderblock would
| hold approximately the same energy as 1 AA battery.
| deltarholamda wrote:
| Man, that will turn my Walkman into a Lugman, no thanks, future
| science.
| NemoNobody wrote:
| The is one of the biggest technological innovations I have ever
| read.
| zorrobyte wrote:
| That will promptly be debunked like solar roadways, etc by
| thunferf00t and others ;)
| pvaldes wrote:
| chasing bugs about to enter at a totally new level in the history
| of computers
| barbariangrunge wrote:
| The cities are already perpetually under construction/maintenance
| and still, there's decade-old potholes in some places.
| Electrified cement: how much more maintenance effort will that
| take? Are the economic and environmental benefits worth it? It
| could be
|
| Also, if it's a smart city and big tech is involved, think of the
| scale of the planned obsolescence issues
| Supermancho wrote:
| > The cities are already perpetually under
| construction/maintenance and still, there's decade-old potholes
| in some places.
|
| Talk about endless construction, see London. Improvements come
| gradually with new construction, then the old are propped
| up/covered up/stripped-and-refaced as long as they are useful
| and upgraded when convenient.
| wudangmonk wrote:
| This has to be a racket to extract as much public money as
| possible. At least in the US and in most cities I have been,
| projects take years and they usually only send a few guys to
| work on it about once per week. A few years later they suddenly
| finish everything in a few months.
| TechBro8615 wrote:
| In software, projects take years and they usually send a few
| guys to work on it for eight hours every day. A few years
| later they suddenly decide to rewrite everything and never
| finish it.
| mulmen wrote:
| Are those workers at home or are they at other job sites with
| closer deadlines? In other words, is the squeaky wheel
| getting all the grease?
| wilg wrote:
| I think it is reasonable to expect a city to be perpetually
| under construction and maintenance.
| NegativeLatency wrote:
| They mention roadways, which makes me wonder: Given that this has
| so much carbon black in it how much more solar energy would it
| absorb that would normally be reflected. Not many pictures but
| the samples look quite dark:
| https://www.pnas.org/doi/full/10.1073/pnas.2304318120
| andrewflnr wrote:
| Is the idea here that there are actually two layers of cement
| separated by membrane? Or maybe more? Anything that breaks up the
| monolithic cement blob makes it worse at its primary job.
| masswerk wrote:
| I guess, this would fail fail on any material properties we use
| cement for in various flavors of concrete in the first place.
| Also, the building material is concrete, not cement. Cement is
| just one ingredient.
|
| (It's kind of sad that a publication like _Science_ would mix
| these up. A road made from cement exclusively would be blown
| away in a minute. Cement is [just] a binding agent for the
| aggregate.)
| criley2 wrote:
| FYI had you read the article, you'd see that they use
| cement/concrete accurately throughout, and are accurate in
| their usage of cement in the title.
|
| One such quote, although it's throughout the article
|
| > The problem is that cement, a primary ingredient in
| concrete, is normally a poor electrical conductor. So, in
| recent years, several groups have made structural
| supercapacitors by spiking cement with highly conductive
| forms of carbon, such as graphene or carbon nanotubes.
| Although these perform well, the ingredients are expensive
| and hard to produce in the massive volumes used in the cement
| industry, notes Franz-Josef Ulm, a civil engineer at the
| Massachusetts Institute of Technology (MIT).
| masswerk wrote:
| But, how and why do you jump from what is to all
| assumptions an interesting surface material to building
| structures? Also, most capacitors are phono-sensitive,
| meaning they react to contraction and tension and all kind
| of vibrations, which wouldn't suggest load bearing masses
| as a prime candidate for this, even if the doping added to
| the cement didn't have any effect on the material
| properties. Let alone the practical problems of having
| significant charges in any structure, like a road or a
| building.
| criley2 wrote:
| So here's some more article quotes lol
|
| > Ulm and his team mixed a small percent of carbon black
| with cement powder and added water. The water readily
| combines with the cement. But because the particles of
| carbon black repel water, they tend to clump together,
| forming long interconnected tendrils within the hardening
| cement that act like a network of wires.
|
| > Ulm and his colleagues cut this wired cement into small
| plates, creating supercapacitors 1 millimeter thick and 1
| centimeter wide, about the size of a button. After adding
| a membrane, an electrolyte made from potassium chloride--
| a simple salt--and water, the researchers sealed the
| sandwich structure. When they then connected a wire to
| the plates and flipped a switch, cement supercapacitors
| lit up a series of LED lights.
|
| > To succeed, researchers will need to scale up the
| button-size plates. Doing that isn't trivial, Nguyen
| notes. As supercapacitors get larger their electrical
| conductivity typically declines, making it harder to
| inject and extract energy from them. One solution, Ulm
| notes, is to simply add more carbon black to the mix--but
| not so much that it weakens the structural integrity of
| the cement. For structural concrete, the researchers
| found they could add up to 10% carbon black without
| compromising too much of its strength. Ulm says the group
| has patented its technology and is now working to scale
| it up to match the output of a 12-volt car battery.
|
| They are well aware of the concept of structural
| integrity and of course the big challenge is scaling up
| their idea in a way that does not compromise it.
| masswerk wrote:
| It's somewhat hard to believe that this (forming lumps
| and adding membranes) does not affect the material
| properties as building material, especially, where
| various flavors of concrete are all about the grade of
| the cement. (Concrete isn't just concrete.) How is this,
| as a capacitor, immune to pressure? How do you jump from
| a 12V car battery to entire buildings and roads?
| DougN7 wrote:
| Yes, and the article didn't touch upon that at all. Building a
| home foundation that would shake apart in a windstorm is a non-
| starter.
| datavirtue wrote:
| You could be hitting on something here. Instead of pouring
| monolithic you could use prefab blocks that are filled in. I
| have used that technique to repair a caved basement where
| cinder block replacements were filled with concrete and
| rebar.
|
| There is a similar system using foam blocks that act as forms
| and are left in place. Menards sells them (and may own the
| manufacturer).
| [deleted]
| datavirtue wrote:
| I would think that the membranes would also be the
| reinforcement. Though I am not getting a good picture in my
| head from the description. It has to be practical. Mix
| concrete, pour concrete...the same way we do it now. There is
| roomm for skilled labor at the reinforcement phase which is a
| precision bit of construction that is inspected closely before
| pouring.
| moomoo11 wrote:
| Dumb question (please don't mad)
|
| Why don't we put springs under massive buildings like skyscrapers
| that anyway move a little bit with wind?
|
| Maybe the millions of tons compressing the springs a little bit
| could result in some electricity?
|
| Or under roads and airport tarmac?
| function_seven wrote:
| For the swaying buildings, you'd almost certainly not get
| enough power out of it to make it worth the cost and additional
| complexity to install.
|
| For roads, whatever power you generate from the traffic would
| be less than the additional power those cars require to drive
| on your road. It would be a net loss. Basically generating
| electricity from gasoline, with extra steps.
| dontrustme wrote:
| Your average architect is _barely_ managing the coordination of
| their structural, electrical, mechanical, civil, and plumbing
| engineers. As green adaptive technology accelerates, it deeply
| concerns me that our notoriously slow moving construction and
| design industry will fail to incorporate these technologies and
| deliver the built environment we need to succeed against climate
| change.
|
| This technology is great, but the real breakthrough will be
| getting someone like Lennar homebuilders to incorporate this into
| their constructions by default.
| datavirtue wrote:
| Use law.
| AlexandrB wrote:
| > This technology is great.
|
| Not yet it's not. There's a world of difference between using
| samples of concrete "about the size of a button" and scaling up
| to something the size of the foundation of a house.
|
| And that just gets it to "buildable". To get to "ubiquitous" it
| also has to be cheap.
| tortoise_in wrote:
| What about flood like situations?
| Ekaros wrote:
| How practical this would be? Considering use cases of reinforced
| concrete and like? Or how sound structurally it would be compared
| to what we currently use? We use reinforced concrete for reasons.
| And if this stops it from working is it really worth the effort?
| wduquette wrote:
| My electronics knowledge is _extremely_ rusty; but don 't
| capacitors discharge all at once? Every so often I see another
| article about using capacitors as batteries, but I've never seen
| one that addresses the discharge issue.
| jjk166 wrote:
| It takes time for them to discharge, and the rate they
| discharge can be controlled by the circuit, just like
| batteries. They just are much less limited in how much power
| they can handle, so they can discharge the same amount of
| energy faster. This is a feature, not a bug, as most
| applications need oversized batteries to handle peak power
| usage which is substantially higher than average.
| seertaak wrote:
| You can just slap a resistor in series, which will induce a
| drop in potential over it. That, in turn, will mean the
| potential difference across the capacitor is lower, leading to
| a more shallow exponential decay of the current over the
| circuit - ie a slower discharge.
|
| And that's just a passive circuit, with an active circuit you
| have a lot more options.
|
| Note: I studied maths and computing so I could very well be
| wrong. I would appreciate being set straight by elec eng
| majors!
| kloch wrote:
| Capacitors do have a different discharge curve than batteries
| and this requires more sophisticated power management
| electronics but nothing too difficult. You basically need a
| power supply/regulator that can start with much less than rated
| input current and increase current draw as voltage drops to
| deliver a constant power output.
| _Microft wrote:
| See also:
|
| _" MIT engineers create an energy-storing supercapacitor from
| ancient materials"_, 85 comments,
| https://news.ycombinator.com/item?id=36951089
| foota wrote:
| Ah yes, ancient materials, like graphene.
| jokoon wrote:
| Shouldn't moderators remove this? This is not /r/upliftingnews or
| /r/futurology.
|
| I know I'm being grumpy and highly skeptical, and that Y
| combinator is about innovation, but why not make a hackernews to
| compartmentalize those things?
|
| I would be okay about a paper that discuss feasibility instead of
| the usual "maybe yes? maybe no." blogspam.
| dang wrote:
| HN's only criterion is whether something is intellectually
| interesting. I don't see why we should remove this one - but I
| do think the baity title could be replaced (this is in the site
| guidelines: https://news.ycombinator.com/newsguidelines.html),
| so I've replaced it with a more representative sentence from
| the article.
| raydiatian wrote:
| Electrified cement? LK-99? Where are the aliens. Who talked.
| slt2021 wrote:
| imagine your house catching random fire just like Lithium ion
| batteries sometimes do while you are asleep.
|
| or some random dude (or a tree fall) punctures the wall of your
| house and sets it on fire
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(page generated 2023-08-01 23:02 UTC)