DIY Electric Car Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
Has anyone read about these?

A capacitor can be used as a battery for a very small amount of energy. The energy stored in a capacitor is (C*V^2)/2.

But recent collaborations between mathematicians and electrical engineers have found a way to optimize the internal surface area of a capacitor, giving it a higher capacitance. The dream is to be able to use a fractal capacitor to store portable energy, such as in a car or other portable device.

We've all seen blogs about using capacitor banks to fuel cars, but you have to have an enormously large capacitor bank in the bed of an EV truck to be able to make it work.

By using fractal capacitors, they've been able to increase capacitance by a factor of about 2.3.
http://www.chic.caltech.edu/Publications/fractal_caps.PDF

It's not much so far, but at least it's interesting.
 

·
Registered
Joined
·
4,302 Posts
That's good news, but even an improvement of 10-fold only puts it in the realm of the best batteries today. Given that those are expected to improve, my suspicion is that capacitors will be playing catch-up in energy density for quite some time. Too, "growing a fractal structure" is liable to be very expensive for quite some time.

Who knows - by the time it's economical maybe EEStor will have a working prototype?

:D
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #3 ·
Yeah, I dunno about EEstor. I read about what they were doing a year or two ago and then just no updates. They still haven't put anything on the market yet, I dunno why.
 

·
Registered
Joined
·
780 Posts
Hi. I agree with Phantom. The cost/size/weight/performance ratio is just not there. The controller will be much happier with the caps close by but I'm not sure it's worth the effort for the whole system.

JR
 

·
Registered
Joined
·
4,004 Posts
I don't think they could ever fully replace batteries, but could certainly help performance as they are much more efficient to charge/discharge.

Just like CPUs use cache on the chip that's much smaller, more expensive, and higher performing than RAM, an EV could use a bank of capacitors to provide a boost for accelerating and could capture regen more efficiently.
 
1 - 6 of 6 Posts
Top