Supercapacitors turbocharged by laxatives

Supercapacitors turbocharged by laxatives
Schematic illustrations of common electrolytes (left) and ionic liquid detergent-like electrolytes (right) on an electrode surface. Credit: Xianwen Mao/Massachusetts Institute of Technology

An international team of scientists, including a professor of chemistry from the University of Bristol, has worked out a way to improve energy storage devices called supercapacitors, by designing a new class of detergents chemically related to laxatives.

Their paper, published today in the journal Nature Materials, explains why these detergents, called , are better electrolytes than current materials and can improve supercapacitors.

Currently, aqueous and organic electrolytes are used, but more recently, researchers and manufacturers have been testing ionic liquids instead to boost performance.

Although ionic liquids are salts, at room temperature they are surprisingly not —as their name suggests they are in fact liquids.

This gives ionic liquids numerous advantages over conventional electrolytes because they are stable, non-flammable, and often much more environmentally friendly.

To explore the exciting potential offered by ionic liquids for emerging electrochemical technologies the authors designed a new set of highly efficient detergent-like ionic liquid electrolytes and explained how they work at electrode surfaces.

Understanding how they operate will help design even more efficient devices for storing electrical energy.

Professor Julian Eastoe, from the University of Bristol's School of Chemistry, is a co-author of the study. He said: "To make this discovery required a team of scientists with a very diverse skill set, spanning , advanced structural, microscopy and electrical techniques as well as .

"This work demonstrates the power of scientific research 'without borders', the groups from different nations contributed their own expertise to make 'the whole greater than the sum of parts'."

Supercapacitors turbocharged by laxatives
Illustration of detergent-like ionic liquids on an electrode surface. Credit: Xianwen Mao/Massachusetts Institute of Technology

Co-author, Xianwen Mao, from the Massachusetts Institute of Technology (MIT), added: "We engineered a new class of ionic liquids that can store energy more efficiently.

"These detergent-like ionic liquids can self-assemble into sandwich-like bilayer structures on electrode surfaces. And that is very reason why they give better energy storage performance."

Typically, for electrolytes in contact with a charged electrode, the distribution of ions is dominated by electrostatic Coulombic interactions.

However, this distribution can be controlled by making the ionic liquids soap-like, or amphiphilic, so that the molecules now have separate polar and non-polar domains, exactly like common detergents.

These soap-like electrolytes then spontaneously form bilayer structures on the electrode surfaces, leading to much improved energy storage capabilities. The researchers found that temperature and applied voltage also affect the energy storage performance.

This new class of electrolytes may be suitable for challenging operations, such as oil drilling and space exploration, but they may also pave the way to new and improved supercapacitors in hybrid cars.

These devices are essential components in modern and can outperform batteries in terms of higher power and better efficiency.

This is particularly the case during regenerative braking where is turned into electrical energy, which can be stored quickly in supercapacitors ready to be released.

This reduces energy consumption and is much more environmentally friendly. More importantly, using the new electrolytes such as developed in this study, future supercapacitors may even be able to store more energy than batteries, potentially replacing batteries in applications such as electrical vehicles, personal electronics, and grid-level energy storage facilities.


Explore further

Scientists cook up new recipes for taking salt out of seawater

More information: Self-assembled nanostructures in ionic liquids facilitate charge storage at electrified interfaces, Nature Materials (2019). DOI: 10.1038/s41563-019-0449-6
Journal information: Nature Materials

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Aug 12, 2019
This gives ionic liquids numerous advantages over conventional electrolytes because they are stable, non-flammable, and often much more environmentally friendly.


Though they have the disadvantage of turning solid soon below room temperature.

potentially replacing batteries in applications such as electrical vehicles, personal electronics, and grid-level energy storage facilities.


Bad idea. Just like trying to store large amounts of energy in a huge spring, very large capacitors fail disastrously. Capacitors store energy in electrostatic tension - dielectric breakdown happens by the opposite charges literally tearing the insulator apart, which can be initiated by a mechanical shock. Here's an example:

https://www.youtu...dxzZ52zU

Aug 12, 2019
@Eikka, is there an energy storage solution you're not against, besides gasoline?

Aug 12, 2019
@Eikka, is there an energy storage solution you're not against, besides gasoline?


I'm not against any energy storage solution; I'm against hyping particular energy storage solutions for purposes they do not fit. In other words, over-promising and riding on popular topics to make something seem more important or impressive than it really is - to sell it rather than simply report it.

Unwarranted hype and over-promising drives public interest, investment and effort, away from the technologies and solutions that have an actual chance of working. It's called the nirvana fallacy: the hypothetical (or misidentified) best is the worst enemy of the pragmatic good.

Aug 12, 2019
Put simply, the insistence that electric cars will some day work with capacitors that carry more energy than batteries today, is like the late 19th century idea that self-propelled horseless carriages could someday operate on engines running on gunpowder.

Anyone who insists otherwise is just a Negative Nelly.

(They did build an engine that ran on guncotton, which is smokeless gunpowder. It worked, for a moment, until the spool of guncotton thread caught on fire.)

Aug 12, 2019
Unwarranted hype and over-promising drives public interest, investment and effort, away from the technologies and solutions that have an actual chance of working.
So name one. You've been against every one on this site since I been here. Not to mention against wind power and solar power every time I've seen you post about them too.

You look like just another liar denier to me.

Aug 12, 2019
So name one.


Well, the fuel cell car lost all interest and stalled in development when BEV cars got all the hype 10-15 years ago, even though fuel cells can operate on a wide variety of fuels, including synthetic fuels made out of renewable energy, reduce CO2 significantly even with fossil fuels, and offer a seamless transition path away from fossil fuels to renewable transportation within the existing infrastructure. It's the good we could have had now, rather than the "best" that we're still waiting for.

You've been against every one on this site since I been here. Not to mention against wind power and solar power every time I've seen you post about them too.


If it works, I have nothing to add. If it doesn't, then it's more important to point out why. Cheering hype with the crowd doesn't accomplish anything.

You look like just another liar denier to me.


Or, you don't like the message, so you shoot the messenger.

Aug 12, 2019
The problem with hype is that it gives people a sense of security that things are going in the right direction without them having to do anything but wait. All the solutions are already made, work, and all that threatens this is the deniers...

But since we're talking about technology, no disbelief or nay-saying can make airplanes fall off the sky or computers stop computing: if it works, it works regardless of what anyone says about it. The results speak for themselves.

If you make a big honking capacitor, charge it up to an energy density that rivals dynamite, and shoot a rifle through it causing the dielectric to break down and short out - without causing a massive electrical explosion - halleluja, you converted me.

Aug 12, 2019
The worst part about hype is when it makes lawmakers and voters believe that something is coming just around the corner, when in reality it's decades away at best.

For example, the fuel economy targets set by governments across the world. Because people like to claim all sorts of fantastical technologies, people have the impression and illusion that the auto-industry is just holding back deliberately out of malice to keep back the "100 MPG carburettor", or electric cars, or whatever - and this justifies targets and limits that are in reality unattainable.

So, the promises made by lawmakers to their voters are unrealistic, and the bureaucrats know this, so they look away when the industry then cheats on those standards, and make even greater promises. This has gone on for so long that reality just can't meet expectations anymore - the system has gone off to la-la-land - and even if the government admitted it and started backpedaling, the voters wouldn't believe it.

Aug 12, 2019
Unwarranted hype and over-promising drives public interest, investment and effort, away from the technologies and solutions that have an actual chance of working. It's called the nirvana fallacy: the hypothetical (or misidentified) best is the worst enemy of the pragmatic good.

Hmm... as soon as I saw the article's headline, I suspected they were talking shit.

Aug 13, 2019
I'm against hyping particular energy storage solutions for purposes they do not fit. In other words, over-promising and riding on popular topics to make something seem more important or impressive than it really is - to sell it rather than simply report it.
But I really don't see hype and certainly no promising here. This site is about advancements in various fields of endeavor. I think this one counts. No, it's not ready for prime time. You correctly pointed out temperature range shortcomings. So yeah, they have to overcome that somehow. Replacing batteries does seem like an out there goal, but it is something that seems to be a goal of most super capacitor developers. Would striking that part make this acceptable to you? Even if this doesn't directly pan out, it could lead to other developments. Yes, I agree, sometimes headline writers need to be taken to the woodshed.

Aug 14, 2019
I'm beginning to wonder if this discovery explains my super capacity gut.

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