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MIT engineers create an energy-storing supercapacitor from ancient materials

news.mit.edu

51–60 of 101 posts

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#51
post #44
post #13

Typical university press release: this technology can revolutionize our energy grid by storing energy in a building’s foundation, because we powered an LED with some tiny cells we made.

Yeah, let's go ahead and store huge electrical charges in the foundations of every new house built! What could possibly go wrong?

i guess the voltage would be rather low... but current capacity might be enough to melt your drill bit, if you decide to drill hole through both of the electrodes :-D

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#52
post #51
post #44

Earlier quoted context omitted.

Yeah, let's go ahead and store huge electrical charges in the foundations of every new house built! What could possibly go wrong?

i guess the voltage would be rather low... but current capacity might be enough to melt your drill bit, if you decide to drill hole through both of the electrodes :-D

Ok, TIL that the high capacity of a supercap doesn't translate into a ginormous voltage (Wikipedia: "A supercapacitor [...] is a high-capacity capacitor, with a capacitance value much higher than other capacitors but with lower voltage limits"). Good to know...

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#53
post #16

Earlier quoted context omitted.

This is one of those sort-of hyperbolic put downs which goes to "we need" encompassing the entire western worlds power requirements. No, you can't replace all existing power sources now and into the future by pumped hydro. Pumped hydro has a massive role to play in power supply, time shifting electricity from renewable sources, providing system resiliency, black start, inductive and inertial load, you-name-it. It als…

I’ve always wanted to ask someone who knew something about this stuff if this idea is feasible: Imagine a giant empty bucket held high in the air. As it rains, the bucket fills and using a counter-weight it slowly lowers down to ground level. Now the bucket is covered and the water is slowly drained causing the counter-weight to lower to the ground and the bucket to rise in the air again. If this were geared properly…

You just described hydroelectric power but with more steps and a much smaller area to catch rain.

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#54
post #38

Harnessing the entropic properties of bulk matter, easily ending up with molecular self assembly, without the need for micromanaging the process--genius! The team calculated that a block of nanocarbon-black-doped concrete that is 45 cubic meters (or yards) in size — equivalent to a cube about 3.5 meters across — would have enough capacity to store about 10 kilowatt-hours of energy, which is considered the average dai…

Lighting rods are actually there to discharge without lighting. In any case 10kWh worth of li-ion batteries is about the size of a water cooler tank, so the whole system - bms, inverter and all - is no larger than a water cooler.

Just a heads up, Chrome flags your HN profile homepage as a "Deceptive site" !!

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#55
post #24
post #6

So i get the electrolyte, but how does this polarize?

When they say capacity increases proportional to volume, do they mean you need to make many alternating thin sheets within that volume?

As few as two sheets would work. But more would be better, yes.

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#56
While I love the ingenuity of this system, I have some trouble seeing it used as an economically viable energy storage option. According to the article, they would need about 45 m3 to store 10 kwh. At a concrete price of 200-300 $/m3, that would come to 9-13.5k USD just for the concrete. That's omitting any costs for the carbon black electrolyte, material processing, electrolyte separators and other things, so a very optimistic estimate.

Meanwhile, battery prices have fallen so much that you can buy 10 kwh of Li-Ion batteries for about $1500 ($150/kwh 2021 prices). The saving grace might be to have it do double duty as a structural element in the building, but many other posters have pointed out that there are many safety and construction problems that would have to be solved for that first.

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#57

Seems to me that the potential of simply lifting a weight up (storage) and down (generation) beats these fancy engineering goals for cost and practicality. Especially if the weight being lifted is a container full of rocks. At first glance there are plenty of those everywhere. No hills or reservoirs needed either. Of course, no papers need to be published ... that may be the goal.

To estimate the cost and practicality, assume you build a tower 120 meters tall and machinery able to lift 60 tons block of concrete to the top, then retrieve the stored energy by lowering it to the ground level. Think for a moment how much that would cost. Then calculate: mgh = 60000kg x 120m x 10m/s^2 (assume acceleration of gravity is 10m/s^2 for simplicity, no energy losses due to friction etc). The result is 72…

Or you could avoid building the machinery and just pump water up and down. Then to lower the cost you could drop the tower idea and use a natural hill with reservoir on top. Surprise, surprise you just invented a pumped-storage power station.

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#58
post #56

While I love the ingenuity of this system, I have some trouble seeing it used as an economically viable energy storage option. According to the article, they would need about 45 m3 to store 10 kwh. At a concrete price of 200-300 $/m3, that would come to 9-13.5k USD just for the concrete. That's omitting any costs for the carbon black electrolyte, material processing, electrolyte separators and other things, so a very…

It might also turn out that lime for the concrete will become a rate limiting material. Not to mention the energy cost involved in mining both it and creating the carbon nanopowder.

But, a material with similar hydration properties to concrete, a biopolymer for instance, might exist and be made with less cost...

We actually have to start thinking about replacing concrete with something else to be more energy efficient and sustainable.

Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#59
post #56

While I love the ingenuity of this system, I have some trouble seeing it used as an economically viable energy storage option. According to the article, they would need about 45 m3 to store 10 kwh. At a concrete price of 200-300 $/m3, that would come to 9-13.5k USD just for the concrete. That's omitting any costs for the carbon black electrolyte, material processing, electrolyte separators and other things, so a very…

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Re: MIT engineers create an energy-storing supercapacitor from ancient materials

#60
post #56

While I love the ingenuity of this system, I have some trouble seeing it used as an economically viable energy storage option. According to the article, they would need about 45 m3 to store 10 kwh. At a concrete price of 200-300 $/m3, that would come to 9-13.5k USD just for the concrete. That's omitting any costs for the carbon black electrolyte, material processing, electrolyte separators and other things, so a very…

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