electricity storage: graphene ultracapacitor-600Wh / kg!

[Obamot]

This is the revolution we were waiting for! Reality has exceeded fiction.

Soon the end of the batteries: charge your electric vehicle with economical graphene ultracapacitors with a lifespan of 50 years, it will soon be possible at low cost!

Richard B. Kaner, and his team:


UCLA professor of chemistry &
materials science and engineering

... have developed a new graphene ultracapacitor
... the "ultracapacitor LSG (Laser Scribed Graphene)»
... inexpensive, with performances unknown to date.

Graphene: "Two-dimensional carbon crystal formed of hexagonal cells".
Harder than diamond, and 200x more resistant than steel to stretching, it seems.


Atomic architecture of this single single layer nano material
(unlike multi-layers of activated carbon supercondos).

Single layer, very flexible and robust, and with no possibility of loss of the electrolyte:



We said graphene difficult and expensive to produce! This professor of chemistry and materials engineering science at UCLA, and his team, have just demonstrated the opposite, and discovered the grail with a very simple method.

They use DVD burners to activate / produce graphene! And they have achieved, as expected, exceptional performance, so much so that they can replace Li-on batteries advantageously.





Video:



Indeed, the performance of these new ultracapacitors already exceeds that of the most efficient Li-on batteries! (100 to 1 times more powerful and 000 to 3 times more dense).

Ultracondos at 600 Wh / kg, VS 200 Wh / kg for the top Li-on

It's a real technological breakthrough when the supercondos were located
in terms of performance approximately between the capacitors and the Li-on batteries:


Source: http://pl.legoff.free.fr/docs/chimie/scapfram.htm

These new ultracapacitors are in the process of replacing the Li-on now:



This finally opens the way for electric vehicles fitted with ultra-reliable graphene ultracapacitors in place of very expensive and relatively restrictive and problematic batteries.

No more performance degradation over time and possibly premature battery wear in case of prolonged non-use of a vehicle or in dillétante.

Electric vehicles will thus, in the near future we hope (in any case with this technology, it has finally become possible) compete directly with naturally aspirated vehicles, without any compromise! And this for a fraction of the cost of transport. Probably: 1 € for 100 km ...

Performance / characteristics of these graphene "ultracapacitors 2.0"

- Electrode surface: 1'520 m2 / gr ... !!! (intrinsic surface of a layer: 2 m630 / gr.);
-> 5 times the surface of the best current supercondos for the same weight, and that changes everything;
- Capacity: 246 Farads per gram;
- Operating voltage: 4 volt;
- Energy density: (distance that the vhc can travel.) 600 watt-hours per kilogram (2,2 lb),
-> approximately 3 to 4 times better than lithium-ion batteries, therefore to be placed in the same category;
- Power density: ultra-high energy density (vehicle speed) never seen with Li-on, exceptional;
- Stability: excellent during charge / discharge cycles of this ultracapacitor.
- Charging capacity: excellent (minimal diffusion of electrolyte ions)
- Comparative energy density: 1,36 milliwatt-hours per cm3, or about twice the energy density of current activated carbon supercapacitors and a density comparable to a high-power thin-film lithium-ion battery;
- Quantity of storable energy: similar or superior to Li-on batteries in less space and with less weight;
- Charge / discharge speed: 100 to 1000x faster than the Li-on (no longer than refueling!);
- Discharge speed: 20 watts per cm3 (1000 times faster than 500 mAh thin-film lithium-ion batteries);
- Comparative discharge speed: 20x faster than activated carbon supercondos (lightning accelerations);
- Weight: 5 times lighter than those with activated carbon for the same power! Or...
- Dimensions: 5 times smaller;
- Conductivity: > 1700 S / m (compared to activated carbon which peaks between 10 and 100 S / m);
- Operating temperature: low (thanks to a conductivity almost 20x higher!);
- substrate: thin plastic film / gel (flexible PET) therefore robust and even foldable;
- Production: inexpensive technology, very easy to reproduce, using a simple DVD burner. No need for binders or collectors, so monolayer. Very easy for mass production on an industrial level with a very low cost price;
- Durability: exceptional, no more electrolyte leakage (a slight loss of 1% of capacity was observed after 1000 cycles.) the admissible recharge / discharge cycles will certainly exceed the life of the vehicle ...;
-> number of cycles: given to 10 cycles, almost without loss of performance, which represents 000 years of use at the rate of 50 days per year with a maximum loss of 200% of capacity in the end!
While on average conventional batteries stand at around 1 to 000 charge / discharge cycles or ... 1 to ten years at most ... And loss of much of the original capacity to 500 % in comparison ...!
- Cost: de facto not too expensive to produce, because very simplified architecture and no need for a cylindrical type construction.

Almost limitless development potential:
- more efficient computers because they are faster and smaller;
- other devices using electronics;
- probable new revolution in imaging (photo, video, 3D etc)
- practically transparent and as good conductor as copper;
- ideal for touch screens;
- light panels, giant screens;
- design of solar cells with unprecedented performance / yield;
- new graphene composite materials (aviation, all vehicles)

What excites many R&D people around the world! Plasmanu's work on Tesla's theories, will soon be able to resume

sources:
http://newsroom.ucla.edu/portal/ucla/uc ... 30478.aspx
http://www.greenoptimistic.com/2012/03/ ... capacitor/
http://www.supercondensateur.com/articl ... raveur-dvd
http://www.futura-sciences.com/fr/defin ... hene_4713/

[Alain G]

Obamot Hi!


It's too good to go out quickly!

I or I have not seen the discharge rate which is important to know if we leave the car unused for a week.

[plasmanu]

who will buy the patent to nullify it
too much innovation goes into the box: danger to the nomenklatura. (elite)

[Alain G]

Shell bought the majority of the photo-voltaics and several battery patents such as that of the EV2, maybe they will buy this one!

[Obamot]

Obamot Hi!
It's too good to go out quickly!

who will buy the patent to nullify it
too much innovation goes into the box: danger to the nomenklatura. (elite)

Anyway it is an accessible techno, now made public ... So who launches ...?

I or I have not seen the discharge rate which is important to know if we leave the car unused for a week.

Ah! The killer question! I do not wish to take a position, but I see it as follows.

There are mainly four self-discharge phenomena:
It has already been said, it seems to me, that there was:
1) very little leakage current.

And we can add the following reasoning;
2) no self-discharge of charges in the pores (since absence of pores, not as with activated carbon supercapacitors);
3) no self-discharge linked to a redox process (the electrolyte is completely isolated in a unique mono-layer design: it is a gel which is sealed). It is in multi-layer supercondos that part of the charges recombine, which constitutes a self-discharge by a few ionic species of opposite charges on the interface which will diffuse towards the electrolyte, in particular because of the surface. porous carbon (whereas with this ultracapacitor, the layer has the thickness of a single atom! which would minimize the diffusion path of electrolyte ions). It is the predominant type of dispersions, during the first hours of self-discharge.
-> the previous phenomenon is due to the presence of water in the electrolyte, but there, not only is it confined, but there is no water (1-ethyl-3-methylimidazolium tetrafluoroborate) and if he has some, she cannot escape (we have already had this discussion).
4) self-discharge due to overvoltage is excluded amha (Tafel equation).

Since this technology is also dedicated to mobile phones, I doubt that it is important. But let's see a little ..

Anyway, it would be enough to go to refuel "arriving»Just before or during parking ... Because like that, the decrease in the voltage across the ultracapacitor, only follows the effect of self-discharge (and the counter-redistribution effect would become negligible). I would also see intelligent ultracapacitors, coupled in groups to a GPS, and which are close to the parking situation:
a) would alert the driver, in order to warn him of the location of the last available charging stations:
b) by default, would be responsible for emptying some groups of ultracapacitors to fill others, so as to leave the group / s remaining full to the brim, and to leave them the minimum of self-discharge until next "full";
c) isolate the emptied groups from the others by a switch off via the on-board computer ...
d) would thus launch the intelligent management of the self-discharge, which would be compensated by a reheating of the ultracondo which would use a small percentage of the charge to prevent the falling temperature causing a faster self-discharge than an uncontrolled self-discharge without reheating ... The heating of the pack, could also be done chemically in an exogenous way (in this case the charge of the ultracapacitor would not suffer from it.)

So like supercapacitors, there would be a greater self-discharge the first 8 hours, but

-15% maximum in 1 week (without intelligent management).
So with full parking between 6 to 9 weeks (to have a little more juice to reach the first terminal by leaving ... or, at worst, the first electrified dwelling ...), as follows:

Self-discharge of a supercapacitor (25 ° C)
- initial voltage of 2,5 V.
- rapid decrease in blood pressure during the first eight hours
- and slow thereafter.

So it seems to me that for the ultracapacitor, we should be a little better the first week -10% with intelligent management, but on the length, it should be worth: from 7 weeks to 10 weeks. I say this in a pessimistic way with a pifometer. Logically there should be less than that. 5 to 7% per week? As follows in green:



And in the event of a “dry breakdown”, the jerrycan would be a large 10 kg ultracondo

But it's just IMHO. I give the floor to the specialists

[Alain G]

Well re (laid) Obamot!

Another thing bothers me, the charge speed and the heat given off, although lower due to better conduction.


N / A! I make you work eh!

You just had to start this topic!

[Obamot]

Sorry, I don't know the ideal possible load models. But given that they advertise a duration equivalent to that of a full tank of gas, it must be:

Full (re) charge time: <10 minutes.
But probably without prior discharge? Does this guy reduce autonomy a bit?
Do fast charges reduce service life? Good luck over fifty years, we don't care

Now, there must be possibly other optimal scenarios, like the supercapacitor night (or half-day) charges, which would start with:
- air conditioning of the pack in its confinement enclosure at a constant temperature of 25 ° C for several hours;
- then before recharging with full prior discharge (very short time required);
- then slow charge by a very constant voltage source (ideal voltage and duration) for about an hour (?)
- reset the pack, then measure the performance of the groups, one after the other, and memorize the available autonomy (or alert in case of a glitch on an element that would de facto be isolated from the rest);
... and so on ...

For temperatures:
It is normally the stability of the electrolyte that limits the temperature! Stability has been described as "Excellent". But I have no value.

- in operation, the supercapacitors datasheet gives admissible operating temperatures from -35 ° C to + 65 ° C. It is possible to adapt the electrolyte so that it descends lower, but it will rise less high ...
And necessarily, these ultracapacitors Laser Scribed Graphene, will do "better":-)

Exceeding the maximum temperature causes the electrolyte of the supercapacitors to decompose, what about those with graphene? I don't know, however, the on-board computer may have a "limit of temp" and stop the vehicle. In addition, naturally aspirated engines also have operating limitations due to temperature, they absolutely need cooling. We can also imagine - as described above - a containment with internal temperature conditioning (exogenously or endogenously, that's not the problem, say cousin, why do you think I proposed that!)

But the charge or discharge between -25 ° C and + 60 ° C differs very little for a supercapacitor, the charging time can vary by approx. 10% it seems.



It remains stable. This is probably due to the fact that the resistance of supercapacitors decreases with increasing temperature. On the other hand, the variations are important for negative temperatures (but one can then condition the temperature of confinement).

So given the high permissible operating temperatures, I deduce that these are not really a problem.

There remains the question of heat dissipation during charging (losses / efficiency), I ignore these figures, but they have no reason to be bad, right?

Anyway, if the temperature increases significantly during charging, it would be beneficial, since the capacity would increase (approx. 10%). That is theoretically.

In practice, if we look at what happens during a fast charge, we see that the capacity is not dependent on the temperature, so the variation can be neglected.

But that still tells us nothing, because the laws of variation can be perfectly modeled by the on-board computer, by a polynomial or exponential law (it depends).

So IMHO, this is not the heel of these ultracapacitors. At worst, by finding the right modeling, we could increase the capacity, which would be a favorable balance compared to the possible loss by heat dissipation ...

As Fernand Raynaud would say about the question of how long it takes for the barrel to cool down, once the shell is out of the barrel: it depends ! If there is wind ... etc

This is how I see it, but I may be wrong ...

[Alain G]

There you give me the operating temperatures and not the temperature based on a fast charge!


I will save you the search since I partly knew the answer and it was to tease you a little that I asked this question!

Since you annoyed Spapshoot to such an extent even if he remained polite despite everything I wanted to make you the same!


And the answer is: since the resistance is very very low the temperature rise should not be a problem with the load.

[Obamot]

tsssss ... it's smart

No doubt, I was going in the same direction. On the other hand, you never got your hands on a legendary Yamaha M2 amp, to see if it gets hot ...:





Or a Denon mos-fet, believe me, it's " hot »
The transistors are not the only ones to cool:



So I would remain cautious, to see with use ...

[Alain G]

PFFFF !!!


Do you want to see mine a hyper mod Adcom ???


8x 6800 uf and 4x mallory 75 000 uf 75 volts
2 x 500 watt transformer for 125 watt / channel output



And 75 amp balanced output!


Feedback loop to almost nothing and able to work easily at 1 ohm!



Modified by Bibi!