
Supercapacitors are now carbon-free and more powerful - Parbeyjr
https://edgylabs.com/2016/11/06/supercapacitors-now-carbon-free/
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kctess5
Classic modern reporting - doesn't link to the source or even cite the paper.

Here's the source:
[http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat476...](http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat4766.pdf)

Web version:
[http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat47...](http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4766.html)

~~~
Pitarou
Not to mention: written by someone who doesn't haven't a clue about what they
are writing about.

I quote:

> ... although conventional batteries have a slower recharging time, the fact
> that they maintain their charging capacity over a longer period because
> makes Li-ion the more efficient choice over carbon-based supercapacitors.

Nope. That's not it.

~~~
akiselev
That description is so bad it makes me wonder whether the author even looked
up capacitors on Wikipedia or if they just paraphrased what they think they
remember from high school physics.

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franciscop
If I'm not mistaken the biggest disadvantage of supercapacitors is the energy
density by mass[1], which means that while they hold a good power density by
mass it's only temporary. Good at sprinting not so good at marathons.

It's great that there are advances in the field for many reasons, but I don't
think they could replace batteries in the short-middle term, which seems to be
the point of the "scientific click-bait" article.

[1] [http://berc.berkeley.edu/storage-wars-batteries-vs-
supercapa...](http://berc.berkeley.edu/storage-wars-batteries-vs-
supercapacitors/)

~~~
Retric
Regenerative breaking systems is one of the obvious places for
supercapacitors. They are not quite at the energy density or cost level where
every car uses them, but with some minor improvements they will become
standard. The advantage is of course better mileage and increased battery
lifespan.

PS: There are even advantages with IC engines:
[http://articles.sae.org/11845/](http://articles.sae.org/11845/)

~~~
lucaspiller
The density/weight needs to be improved a lot for it to be effective compared
to existing battery technologies though:

Mazda supercapacitor:

0.007kWh @ 6kg - 857kg/kWh

Prius with nickel-metal hydride batteries:

1.3kWh @ 42kg - 32kg/kWh

Tesla with lithium-ion batteries:

85kWh @ 544 kg - 6.4kg/kWh

~~~
Retric
Breaking systems only really need to contain enough energy to stop a car. So,
up to 1/2 * 2,000kg * (40m/s)^2 = 1.6e6 J which is a lot of energy, though
less than 3.6e+6 J. Going down a mountain is an important edge case, but
frankly not something that you really need to use super caps for as these
systems still have mechanical breaks for backup, and the lower peaks is more
acceptable for battery's.

In an electric car you would then use that energy to speed up again, thus
allowing for 10s if not hundreds of charge cycles on a single trip.

Note: 2000kg ~= 4,400lb, 40m/s ~= 90mph.

~~~
sjfiekzjndn
You forgot to divide by two.

It's actually 1.6 MJ, not 3.2 MJ.

~~~
Retric
Just edited before seeing your note. But, thanks I always forget about that
1/2.

~~~
abakker
Just to be pedantic, it is "brakes" for slowing things down, and "breaks" for
ruining or damaging something.

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mchannon
Carbon-free implies that there is zero carbon in this technology. In fact, the
MOF material is based on organic (carbon-bearing) molecules.

"non-carbon-based" would be more apt, since this is definitely a change from
carbon-based electrodes.

~~~
takingflac
I agree the current phrasing is at best easy to misunderstand at worst
misleading. Another phrase like mchannon is suggesting or perhaps "No longer
uses just carbon" would be more acceptable.

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gene-h
MOFs are one of the coolest nanomaterials. They are easy to customize and are
sort of like molecular tinker toys. One can make a new MOF with the same
structure by exchanging one of the molecular struts for another. In addition
they self assemble and can be made by the ton. I don't think we can make
carbon nanotubes by the ton.

Chris Wilmer, a well known MOF researcher and bitcoin proponent, has an
interesting talk on MOFs:
[https://www.youtube.com/watch?v=n1hcF2kYlC0](https://www.youtube.com/watch?v=n1hcF2kYlC0)

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flexie
That is good news. How long time would it take this research to result in
improved batteries being marketed for electric vehicles?

~~~
baldfat
this is one of a hundred such new battery technology we have been reading for
the last 15 years. Batteries still have not changed in any great leap yet.

~~~
flexie
I don't know if that's true but save for electric vehicles, has there been any
major interest in improving batteries much beyond what they do?

Batteries have been mass marketed for laptops and cellphones in the past
couple of decades and have improved steadily for the increasing needs in those
markets. It's okay for cell phones to last for a day and to charge in an hour.
But with electric cars, which are only really starting to pick up in the last
2-3 years or so, demand for longer range and faster charging is quite
different.

~~~
baldfat
[https://blogs.scientificamerican.com/the-curious-
wavefunctio...](https://blogs.scientificamerican.com/the-curious-
wavefunction/moores-law-and-battery-technology-no-dice/)

------
audunw
Charging speed is almost irrelevant for EVs. In the end you're limited by the
amount of power you can push through a liquid cooled charging cable, and
traditional batteries can almost certainly be engineered to handle that
current.

Once you get to that level, further improvements will not be that interesting.
Maybe we'll never reach ICE refueling speed. But with electric you can put a
charging spot on every parking space in supermarkets etc, and people can just
leave the car charging while they shop.

Energy density is the only thing that matters.

Good super capacitors have other great usecases though. But maybe not as sexy.

~~~
nbadg
This may be true at first glance, but if you try to incorporate more advanced
EV features, and in particular, regenerative braking, you very quickly do need
to care about maximum charge/discharge rates. Your brakes dissipate a great
deal of energy very quickly; to resorb that back into usable potential is
something that supercaps are exceptionally good at facilitating.

That being said, in this case, you're likely best off using a supercap buffer
between your batteries and the wheels, but that makes your power management
and delivery systems substantially more complicated.

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cheiVia0
Could this be used to charge your car's supercaps in 30s and have them feed
into the batteries over a longer period of time?

~~~
vincnetas
I think charging cables would melt from such currents. Or you would need a
superconductor charging cables for your supercapacitors. Super everything :)

~~~
fzzzy
Could use higher voltages instead.

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achr2
Not for supercaps, most have a breakdown voltage below 5 V.

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Cerium
That's not important, the batteries also explode if you take them over about
4.2v, you can stack them up to get the desired system voltage.

