Graphene batteries and supercapacitors

[California98Civic]

Originally Posted by sendler

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. ...

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.

[RedDevil]

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!

[freebeard]

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.

[sendler]

Originally Posted by California98Civic

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.

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.
.
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.

[freebeard]

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.

"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."

[Grant-53]

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.

[redpoint5]

Originally Posted by Grant-53

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.

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

[rmay635703]

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

Graphene ambient temperature electricity source

[jakobnev]

Graphene ambient temperature electricity source

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

[redpoint5]

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?