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Matt Patterson

Are glass batteries a hoax?

33 posts in this topic

Too many times are things too good to be true. It seems to me if it were really true they could use materials like graphene. Or make such bold claims as the beginning of perpetual energy if it charges in as little time as they say.

If it is real how many years till it is used? Or widespread?

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Posted (edited)

Context, for those(*) who had no idea what this was about: http://spectrum.ieee.org/energywise/energy/renewables/does-new-glass-battery-accelerate-the-end-of-oil

 

(*) Me.

 

 

 

The new battery technology uses a form of glass, doped with reactive “alkali” metals like lithium or sodium, as the battery’s electrolyte (the medium between cathode and electrode that ions travel across when the battery charges and discharges). As outlined in a research paper and recent patent filing (of which Goodenough, 94, says more are forthcoming), the lithium- or sodium-doped glass electrolyte offers a new medium for novel battery chemistry and physics.
Edited by Strange
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Context, for those(*) who had no idea what this was about: http://spectrum.ieee.org/energywise/energy/renewables/does-new-glass-battery-accelerate-the-end-of-oil

 

(*) Me.

 

 

Hey, UT Austin! My alma mater!

Matt Patterson: Goodenough has a solid reputation, so I'd be shocked if it's a "hoax" in the deliberate sense. Hopefully further work won't be disappointing. That article Strange linked directly addresses all of the areas where we need breakthroughs: energy density, lifetime cycle count, charging time, and SAFETY. If it works out it will change the game completely.

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Solid state electrolites (such as ion-conducting glasses) are nothing new. The problem is that conductivity of solid electrolytes (and especially that of glasses) is much lower than conductivity of liquid electrolytes. This is very difficult to change because it is based on physic's laws.

Li-ion batteries commonly use organic electrolytes. They may not be too cheap and are flammable, but at least they offer acceptable power densities (which are still not too exceptional). With glass electrolytes power may fell below acceptable level. The article doesn't mention this problem. I don't think its likely energy density will grow a few times with glass electrolyte. Why exactly?

Do they expect that glass electrolyte will take much smaller amount of space than a liquid one? If yes, why?

Some expressions from the article are difficult to comprehend of believe in them instantly. For example:

glass battery charges in “minutes rather than hours.” This, she says, is because the lithium- or sodium-doped glass endows the battery with a far greater capacity to store energy in the electric field. So, the battery can, in this sense, behave a little more like a lightning-fast supercapacitor. (In technical terms, the battery’s glass electrolyte endows it with a higher so-called dielectric constant than the volatile organic liquid electrolyte in a lithium-ion battery.)

 

Batteries and capacitors store energy in different ways. What is good for a one is hardly good for another. High dielectric constant can be barely useful for a battery or a supercapacitor. Only for a dielectric capacitor.

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Well, they mentioned that they can be charged much faster than Li-ion batteries. It's hard to see why power would go faster one way but slower the other way. I'm definitely not an expert, though.

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Well, they mentioned that they can be charged much faster than Li-ion batteries. It's hard to see why power would go faster one way but slower the other way. I'm definitely not an expert, though.

 

What is a field of your expertise?

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I'm an electrical engineer by training, but I don't claim familiarity with battery chemistries. I do have a good understanding of EM field theory and so forth, though. Within EE I'd say my specialties are digital electronics / computer architecture and also electromechanical energy conversion.

 

What's yours?


My undergraduate training and the largest part of my career relate to the digital electronics area. My PhD research and the smaller part of my career relate to the electromechanical conversion area.

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Posted (edited)

I'm an electrical engineer by training, but I don't claim familiarity with battery chemistries. I do have a good understanding of EM field theory and so forth, though. Within EE I'd say my specialties are digital electronics / computer architecture and also electromechanical energy conversion.

 

What's yours?

My undergraduate training and the largest part of my career relate to the digital electronics area. My PhD research and the smaller part of my career relate to the electromechanical conversion area.

I'm too modest to claim an expertise at something. I'm an amateur inventor and my interests presently are at the fields of energy storage and conversion devices.

Edited by Moreno
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One of the things I love most about the modern era we live in is the resources it makes available for self-education. I think it's a wonderful thing. Also, I don't want to be perceived as taking the recent battery announcement as a slam dunk done deal. It absolutely could fail to prove out. But one can certainly hope otherwise; maybe this will be one of the rounds we win. It would certainly be a good thing for the planet. I've never been very enthusiastic about electric vehicles. It's cool technology, and I was loosely connected with a couple of EV programs while I worked at UT Austin. But I've always felt that the battery technology available was limiting. What people (many, at least; perhaps not all) is a vehicle they can take a road trip in. That means being able to hold several hundred miles worth of energy, which batteries are at least in the ballpark for. But it also means being able to stop at a service station and re-fuel in a period of minutes, which batteries have not offered previously. If this announcement lives up to the stated potential it could change that.

 

Energy storage and conversion is a fascinating field; I very much enjoyed working in that area. I found it necessary to move to move from Austin to Houston for personal reasons, though, and the job market at the time took me back into digital electronics. Which can also be very fun, but I sometimes think that the 1990's was the high water mark for people with my particular skill set. I think the most interesting things going on in electronics today are at the VLSI level. I still remember the UT work with enormous fondness.

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Posted (edited)

I've never been very enthusiastic about electric vehicles. It's cool technology, and I was loosely connected with a couple of EV programs while I worked at UT Austin. But I've always felt that the battery technology available was limiting.

 

Fortunately, electrically rechargeable batteries is not the only technology which could make EVs to dominate. I even wouldn't expect it will be the batteries. With their dirty chemical reactions they don't look like a futuristic energy storage.

I propose you to regard supercapacitors, metal-air fuel cells and long-distance wireless energy transfer.

Also, EVs is not the only type of a vehicle worth of the inventive efforts. In this century hybrid vehicles may become dominant. If plug-in hybrid will allow to save 80-90% of organic fuel annually, we may say that problem of EV is almost solved and celebrate.

Edited by Moreno
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Well, fuel cells still use fuel; it's not an all-electric technology that could use electricity sourced by nuclear power. I think we've talked in another thread about capacitors vs. chemical energy storage. Humans have accomplished too many amazing things for me to say "never" very easily, but pure electric energy storage has a tough challenge to compete with chemical storage. I believe the point I made in the other forum was that the former stores energy via fields without breaking / forming chemical bonds, whereas the latter does have access to the full energy of those bonds. Like I said, I won't say never, but I have severe doubts.

 

I'm not fixated on any one thing - "whatever gets us there" is great in my book. I just think that if the team at UT can make battery capabilities such as the ones mentioned in the article commercially realizable, then it could make a real difference. Electric already has a lot of advantages over internal combustion (not the least of which is efficiency). Safer, more economically competitive, and safer batteries could put them on the inside track.

 

Can you recharge a fuel cell? By that I mean by inputting electrical power, as opposed to adding fresh fuel. If so, how fast is that process?

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Well, fuel cells still use fuel; it's not an all-electric technology that could use electricity sourced by nuclear power.

 

Can you recharge a fuel cell? By that I mean by inputting electrical power, as opposed to adding fresh fuel. If so, how fast is that process?

Aluminum is produced with help of electrolysis from aluminum oxides. You can use cheap electricity from remote sources, or electricity from nuclear or hydroelectric plants produced at night. This is how most of Aluminum is produced presently.

You can just fill a fuel cell with Aluminum powder or wire at the fueling station. It will take couple of minutes.

I think we've talked in another thread about capacitors vs. chemical energy storage. Humans have accomplished too many amazing things for me to say "never" very easily, but pure electric energy storage has a tough challenge to compete with chemical storage. I believe the point I made in the other forum was that the former stores energy via fields without breaking / forming chemical bonds, whereas the latter does have access to the full energy of those bonds. Like I said, I won't say never, but I have severe doubts.

 

It's predicted that a flywheel made of diamond wire would have 15 MJ/Kg energy density. Similar or even higher estimates are made for carbon nanotube wire, boron fiber or nitrogen fiber. Compare it to 3.5 MJ/kg for a hypothetical, yet to be created Li-air rechargeable battery, which suppose to have the largest energy density of all batteries.

I have suspicion that both flywheels and capacitors belong to a similar class of an energy storage devices which store their energy in atomic bonds deformations. Therefore it may give a clue about capacitors future limits.

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Hmmm. I haven't done any flywheel calculations in a long time. Flywheels don't actually store energy by stretching bonds; the bond-stretching is a by-product of the stress created by the rotational motion. The first order storage is purely kinetic. But the bond strength would of course be one of the limiting factors. I still think it will be hard to compete with a storage technology based on completely forming and breaking bonds as the primary mechanism, but I guess we'll see way or the other. The market will pick a winner from whatever contenders appear. I guess the next year or two will tell us a lot more about the viability of the glass batteries.

 

The outfit I worked with at UT was heavily into flywheel storage - the flywheel being the rotor of a pulse mode generator. Our main research was in using such things (which we designed in-house), spun up slowly with a hydraulic motor and then discharged over a very short period, to generate electrical pulses used to fire railguns. The main competition was Maxwell Labs, who focused on capacitor-based technology for the most part. This all ancient history, though; going on 30 years. At the time the military was really interested in deploying railguns on tanks. In the end they gave it up, though. Gunpowder was just too good at the job.

 

I'm hitting the sack for the night - catch you again later. Maybe before I sleep I'll put in a pre-order for my very own De Beers flywheel. :)

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Hmmm. I haven't done any flywheel calculations in a long time. Flywheels don't actually store energy by stretching bonds; the bond-stretching is a by-product of the stress created by the rotational motion. The first order storage is purely kinetic. But the bond strength would of course be one of the limiting factors.

 

I'm hitting the sack for the night - catch you again later. Maybe before I sleep I'll put in a pre-order for my very own De Beers flywheel. :)

Honestly, I have no trustworthy calculations for flywheels made of "supermaterials". For example, this one article mentions 1100 Wh/kg for a hypothetical carbon nanotube flywheel.

http://www.nanowerk.com/spotlight/spotid=22055.php

 

Yes, I meant that in both flywheels and capacitors atomic bond strength is a limiting factor. In capacitor you may play with some quantum effects furthermore, I assume. What do you mean under "bond stretching"?

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Oh, well, when you spin your flywheel a stress distribution arises in the material due to the outward force caused by the rotation. So you also get strain per the stress/strain relationship of the material. That's basically a stretching of the chemical bonds in the material's crystal lattice. If you spin the flywheel too fast you exceed the yield strength of the material and it flies apart. That's all I meant. All that stuff boils down to something going on at the atomic / molecular level.

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The problem with flywheel, however, it that if it's made of non magnetic material (similar to a diamond fiber) I wonder how they are going to use magnetic bearing with that.

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Posted (edited)

The thing is with a flywheel, that the energy density isn't critical for all applications. So you don't always have to be using such high speeds, or expensive materials.

I don't think that flywheels will ever be suitable for road vehicles, because of the forces involved if you change direction. Maybe on a straight railway track or a ship you could get away with one.

They are most suitable for static installations, and in those instances, energy density isn't so critical because weight doesn't matter so much..

Instead of spinning it so fast that you need exotic materials, you just use lower speeds and a bigger flywheel. The main cost comes in building and maintaining a safe and efficient housing and bearing.

 

I think that batteries will remain the best alternative to fossil fuel for road vehicles, unless capacitor technology can overtake them.

 

Edit :

I clicked on the link about carbon nanotubes, and I think they are talking about using them as some sort of superior spring, which has a much higher strength to weight ratio and greater durability than current spring materials. Maybe that could be installed in vehicles, in some way, and you just pay at stations to have your spring wound up? It might have safety implications though, if something breaks.

Edited by mistermack
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The thing is with a flywheel, that the energy density isn't critical for all applications. So you don't always have to be using such high speeds, or expensive materials.

I don't think that flywheels will ever be suitable for road vehicles, because of the forces involved if you change direction.

What if you use two flywheels which rotate in opposite directions on car?

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Well, I'm no expert, but from what I've read, a flywheel tries to maintain the direction of it's axis, and that would apply for both flywheels in the same way. So it's resistance to change, not directional, I think.

I would imagine that it would be best to mount it vertically, as you don't meet many steep slopes, so that axis would be the most stable.

I don't know how acceleration and braking would affect the flywheel though, although I'm betting that it's been tried and there is info online.

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Actually if they are counter-rotating at the same speed then the gyro torques cancel "externally." Whatever structure is holding them in a parallel configuration will experience stresses, though, so that would have to be a strong enough design hence weight etc. I actually "experienced" this recently - my wife bought my daughter a couple of those little spinner thingies people use to just play with or spend nervous energy. I could hold one between my thumb and finger, spin it, and feel the gyro torques. But if I held two and spun them opposite directions (matching speed as best I could) that effect was much diminished.

 

These gizmos:

 

http://www.asseenontvandbeyond.com/Fidget-Spinner--The-Original-Stress-Relief-Toy_p_357.html?gclid=CjwKCAjwjPXIBRBhEiwAz-kF6Q65lc10fWJHVOZ-sQcSuW9mDPS7nKAosobLxjXtjiZo03OVvIYCPxoCI_gQAvD_BwE

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Actually if they are counter-rotating at the same speed then the gyro torques cancel "externally."

I don't really understand what that means.

From memory, if I held a spinning gyroscope in my hands, it resisted being turned to the left, and to the right, equally.

So I was imagining that two parallel ones would just double the resistance to turning.

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Posted (edited)

They would if they are turning in the same direction. But if they are turning in opposite directions you won't feel that resistance (if they're turning at the same speed and have the same mass distribution).

 

You're right that there's resistance to either direction of turn. But there's still a cancellation effect when the flywheels are counter-rotating. I'd probably have to go to a reference to express it mathematically, though.

Edited by KipIngram
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I can help you out in that respect, since it is quite simple:

L-L=0

With L the angular momentum. Both angular momentums cancel each other out, and the resulting angular momentum is zero. Without angular momentum, no gyroscopic effect.

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Ah, are you talking about two gyroscopes rotating on the same connected axis?

 

I was picturing two parallel. If the two are connected through the axis of rotation I can see how they could cancel each other that way.

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