Graphene batteries and supercapacitors
 

In May a South Korean group announced a graphene supercapacitor "breakthrough" that could produce very short charging times:
Breakthrough for electric cars: Supercapacitors from miracle substance graphene charges batteries in 4 minutes

And in this older report, a Berkeley group is described as developing graphene batteries: "The Berkeley team is eyeballing the new technology to develop a low cost electric vehicle battery in the 300 mile range, so stay tuned."
Graphene Could Kill Lithium-Ion Batteries | CleanTechnica

I wonder how much of this is hype, and when some of these technologies might make an appearance in cars or even battery products sold directly to the consumer market.

There is so much hype on different battery chemistry types right now. Its very encouraging to see all the research and development going on in that area. Time will only tell which ones will actually prove viable in real world applications.

Hmmm: 10 kwh in my volt pack. 4 minute recharge. Awfully big current numbers to get recharged. Pretty sure it would melt 2/0 cables, and set fire to the li-pos.

That's a good point. There would be a need for new charging infrastructure, wouldn't there?

Batteries get hot when they get charged because of their internal resistance.
The whole point of having graphene or unobtanium or whatever is just to reduce that resistance.
They would not get as hot while being charged; ideally even a full charge could not produce enough heat to trouble them, doing away with the need of forced cooling.

The current episode of EVTV had mention of improvements from 24m (which rose from the ashes of A123) and Samsung. 24m has a way of layering the electrolyte and Samsung had something to do with the electrodes. Now I need to watch it again.

Irrespective of heating, a fast recharge of a massive battery must be like a mini-lightning bolt passing through a cable you can grasp in your hand. :eek:

Can we harness lightning bolts yet? Aren't there some places regularly hit by them?

That wold be like taking the whole fast charging problem, and multiplying by itself.

Edit: The Samsung announcement involves anodes made of silicon instead of carbon, wrapped in graphene sheets because the silicon swells and shrinks through the charge/discharge cycle.

So, something different. It's the usual 2 to 3 years out.

It's all hype until it actually exists and is available to the public.
JJ

10 kWh in 4 minutes is a charge rate of 150 kW. On 240 volt, that would be 625 amps. The typical household service is only 200 amps.

You would want a much higher charging voltage to keep the amps at a reasonable level. Even at 600 volts, it would take 250 amps to supply the 150 kWh rate.

Fun stuff.

If I had an EV I wouldn't need to charge it in 4 minutes at home. 4 hours would be fine.
But I'd love it if a charge would take only 4 minutes en route, at the 'gas' station.

Suppose the charging stations need to charge 120 cars per hour.
They'd be able to do that with 8 4-minute chargers, or 120 1-hour chargers.
They'd draw the same power from the grid, but the charge station infrastructure needed for the first setup would be much less.

4 minute charging means you don't have to charge at home, as charging on the go won't set you back for more than a few minutes.

I think there is more to it. The grid is AC while the charging is DC, so 8 inverters or 120? And one of the proposed uses for the Gigafactory is to add battery banks to the nodes on the Tesla Supercharger network.

Or even something like this: Zebra

Random recheck to see the market status of graphene batteries reveals this. And rough calculations suggest my ebike would get a little more energy capacity in slightly less space and with much less weight.

"LRP TC Stock Spec P5-HV Graphene 2S LiPo 60C Battery (7.6V/8000mAh). The HV-LiPo Graphene cells offer even more power than before and can be charged up to 8.7V without problem. The improved cell chemistry generates an extremely low internal resistance and therefore less heat buildup under load. HDS-7 cell chemistry guarantees maximum performance. Specially developed for stock racing classes with highest possible voltage output for maximum speed and acceleration.

P5-HV Technology: 5mm gold plated battery plugs and 7.6V (2S) technology for maximum power
HV-LiPo GRAPHENE cells: High power LiPo cells that can be charged up to 8.70V (2S)! Maximum Power!
100% compatible for 8.40V (2S): More Power than LRP 2016 batteries at 8.40V charging!
Improved Lifetime: Highly improved lifetme when charged to 8.40V (2S) only!
HDS-7 Chemistry: Improved chemistry for low internal resistance + less heat build-up under load = Maximum power until the end of your run
5mm Gold Works Team connectors included
3C Charge current
Charge with your standard LiPo charger for 8.4V or with LiHV charger for 8.7V
Complying with the rules of the following federations and race series: EFRA, IFMAR, ROAR, JMRCA, BRCA, DMC
120C/60C LiPo Power No memory effect, extremely long lifetime.
Durable, see-through, hardcase made of high-quality synthetic material
2mm gold coated balancing connector
LRP quality approved
Specifications:
Length: 139.0mm
Width: 47.0mm
Height: 25.1mm
Weight: 332g
Capacity: 8000mAh
Nominal voltage: 7.6V
C-rate: 120C/60C
Style: TC Stock Spec
Power connector: P5 5mm Gold
Balancing connector: 2mm Gold
Charge current: 3C
Application: 1:10 Onroad TC Stock + Modified
This product was added to our catalog on March 24, 2017."

And assuming you have a 625 amp charging supply, keeping a good contact is the problem. You certainly couldn't use a plug in connector. If you have a resistance in the wiring/switching/connectors of 0.01 of an ohm (100th of an ohm), the heat developed at that resistance, at 625 amps, is 3.9Kw. I worked on high current circuits and we used OFHC copper (Oxeygen Free High Conductivity), and it was a nightmare to keep connectors clean, tight and not overheating. That's why mercury switches are used in high current industrial switching.
We were operating at 1000 Amps, and the copper cables were as thick as your wrist.

I'm not sure where to put this, so:

Nano aluminium offers fuel cells on demand – just add water
https://www.newscientist.com/article...ust-add-water/

I don't see why a little battery like the one described above needs such a mamoth power supply. ??

It doesn't. But it does if you want to charge it in 4 minutes. You have to get all the energy you would normally put into the battery overnight in during the small time. If it takes 8 hours to charge, normally (just a number for arguments sake), you have to supply that same energy at 120 times the rate, to charge in 4 minutes. The only way you can do that at the same voltage is masses of current.

Ah. I get it. But I am just talking about an ebike, not a car. So just a 16ahr battery. Still, if it were a car, slow charge at home would be fine overnight or during a few hours. Leave the fast charging to charging stations. I imagine that as graphene tech gets better, we'll get several times the range into a battery only about as heavy as they are currently. More cycles too. That will be big.

If the graphene battery's main claim to fame is higher instantaneous power, that is not really what the electric vehicle needs to progress. Range versus cost versus cycle life is the big issue. And these graphene batteries cost a fortune. And what is the cycle life if you are always charging them at 12C? A large EV battery needs at least 2,000 cycles to 80% to make a 300,000 mile life so as to fulfill it's promise of being cheaper than an ICE car.
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We already have batteries that are so large in capacity that a 2C discharge is 170hp. We don't need 90C. And as the capacity of EV batteries goes to 60 kWh as a norm, the charge rate will become more and more limited by the cable and connector (And Infrastructure if you think you are going to have a station charging 10 EV's at 250kW all the time) than the battery. Higher rates than 150kW at 400v that Tesla is approaching will require a split pack design that can run at 400v and charge at 800v to keep the current down.

You are right that that's the big issue. But range/cost/life is not the only issue. A second major issue for potential buyers is the worry that it will take four hours to charge the car. Sitting around that long at a fueling station turns some people off. Faster discharge will apparently mean faster charging. Supposedly graphene also has greater power density and a longer life cycle. So, I guess the pursuit of it is to try and answer the problem you identify, and more.

But it is significantly more expensive in the consumer applications that seem to be appearing finally. But that would possibly change for the better over time.

I agree. Cars may not need graphene batteries.

Phones and tablets though... Bump charge in minutes? There's a market for that.
Our iPad is always begging for food. The kids play games on it that makes it run almost too hot to touch!

A Better, Safer Battery Could Be Coming to a Laptop Near You
https://www.nytimes.com/2017/08/01/t...thium-ion.html

Cheaper and safer. No mention of charge times.

dc fast charging will charge a Bolt or a Tesla in 1 hour. Tesla is at the limit of the cable and connector at 120kW charge rate. 300 Amps. This is already almost three times as much power as a modern USA home can source. When they build new dealerships, they have to put in new high voltage cables for miles back to the nearest cross country HV line and install their own substation at the chargers. 8 cars at a station, and more behind them in line. The station is sucking 1,000 kW out of the grid. Would go to 6,000 kW if the cars start charging in 10 minutes. There are other limits holding back fast charging times. Not only the battery inernal impedance.
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It will be interesting to see what the maximum charge rate Tesla will allow in the the new cells of the model 3. New size and the latest chemistry. Since it is a smaller pack than the big model S packs their stations would be able to fill it in 1/2 an hour if the battery will be allowed to charge at 2C.

"I won't give up that one thing ('instant' refueling) in order to make the world a better place."

"You should eat slower and chew your food."

The use of super capacitors might open up avenues for faster charging stops. One would need to run the calculations for an induction charge of a large capacitor which would then do a measured charge of the batteries. Fueling stops are now measured by the time it takes to use the restroom or buy a soft drink. A commuter vehicle would only need an hour of run time between charges. For most of us time is money so drive time is part of the average annual cost of operation.
To reduce congestion and energy use, consider a streamlined e-bike for trips under 25 miles.

If the supercap has the charge, why would the car need a battery?

http://www.sciencealert.com/graphene...tronic-devices

Graphene ambient temperature electricity source

Converting heat into work without a temperature difference would violate the 2nd law of thermodynamics.

Yeah, I'm not quite understanding how one would go about capturing vibrational (heat) energy of the atoms when their motion is random (complex).

I always hear about the great inventions graphene will allow, but very little materializes. We have supercapacitors that are a couple thousand Farads now, but what else do we have? I want to see an elephant standing on the end of a pencil that is suspended by a paper-thin sheet of graphene. I want to see graphene rope the size of dental floss that can pull a tractor out of a ditch. How about batteries that don't destroy themselves over time?

Bownian movement happens anywhere there isn't a [3D] crystalline matrix, IIRC.

Quantum particles fluctuate in and out of the Multiverse all the time and everywhere.

*(Mathematician and inventor of ancient Greece, 280-211bc)

We just need to borrow energy from the multiverse before they figure out how to steal it from us. Perhaps energy cannot be created or destroyed, but it can be moved from one place to another.

If you could convert the vibration of atoms (heat) into electricity, wouldn't that mean the graphene would cool (vibrate less) in proportion? You would need sufficient surface area with ambient air to replenish the heat.

I read a sci fi story where one multiverse pulled mass from others until there was enough concentrated to create a big bang.

That is the best explanation that I have ever read.

Beware the Multiverse. it's not like parallel Universes.

It's an interpretation of Quantum physics where the notional universes constantly influence each other, reconciling with each other (like a blockchain reaching consensus) like a heartbeat on Planck time.
Se also Eric Dollard. He posits that mutli-phase Alternating Current is trading energy back and forth in time (with phase shifting) in this Universe.

http://ericpdollard.com/wp-content/u...rd-corolla.jpg

http://ericpdollard.com/wp-content/u...rd-corolla.jpg
^^The car (mit antennae) Eric Dollard has lived in for the last 25 years.

I’m not sure it has to.

Can overall entropy increase because of a localized decrease of one form of energy?

An ICE generates energy by cooling combustion gases

This proposed device would cool local atoms creating a heat differential with the environment and electricity.

That said how would one collect energy out of a many ghz signal at the nano level?

Sounds unpossible

An ICE CONVERTS heat from the fuel into motion. At a big loss. Molecules vibrate due to heat. If you take energy out of that vibration they will be cooler and need more heat from somewhere.

Basically what was proposed is a variation of this: https://en.wikipedia.org/wiki/Brownian_ratchet

Gotcha, but another issue is a physics one

The act of observation changes what you are observing at a nano scale

What they believe is happening can’t be known with certainty and further no device could pull localized energy present in a Nano structure for the same reason

Like the "Darwin Awardee's" there seems to be a HUGE pool of "Unicorn Awardee" candidates! Pass out those TIN hats!

Capturing heat energy is to quantum physics as capturing wave energy is to Aristotelian physics. It should be possible, but we're much better at manipulating large quantities of stuff than putting quantum physics to work for us.