
Could hemp nanosheets topple graphene for making the ideal supercapacitor? - dutchbrit
http://www.acs.org/content/acs/en/pressroom/newsreleases/2014/august/could-hemp-nanosheets-topple-graphene-for-making-the-ideal-supercapacitor.html
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anigbrowl
_Fully assembled, the devices performed far better than commercial
supercapacitors in both energy density and the range of temperatures over
which they can work. The hemp-based devices yielded energy densities as high
as 12 Watt-hours per kilogram, two to three times higher than commercial
counterparts. They also operate over an impressive temperature range, from
freezing to more than 200 degrees Fahrenheit._

One wonders what the economic opportunity cost of the drug war has been.

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brianbreslin
Just gonna put this out there, but I swear this plant is like a miracle
worker. Imagine what advances we would have made if this war on drugs hadn't
kept hemp out of our reach for so long. Though someone please clarify if you
can get hemp without marijuana (I am curious).

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cfreeman
It's not as miraculous as some people in the US will go on and on about. I
mean, it is definitely a useful plant but it's legal in many countries and
hasn't become a major crop.

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danford
It's not technically legal in any country because of a UN treaty. I think part
of the reason it hasn't 'taken off' in countries where laws aren't
enforced/it's decriminalized/etc is because you can't transport it over the
border, you can't sell to big clients in America (or anywhere else), the laws
regarding distribution on such a large scale aren't clear enough even in
places where it is "legal" so no one wants to put all their eggs in the
marijuana basket at this point.

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lotsofmangos
_His team found that if they heated the fibers for 24 hours at a little over
350 degrees Fahrenheit, and then blasted the resulting material with more
intense heat, it would exfoliate into carbon nanosheets._

Sounds like a similar process to the carbon-complex stuff that the ryden
battery people are making from cotton. Nano materials might be easier to get
in industrial quantities than I had previously thought, if you can strip them
out of plants rather than having to build them up chemically. There presumably
is an interesting crossover point here with genetic engineering, where you
could alter a plant genome to encourage the formation of particular
structures.

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Geee
The energy density is still nowhere near Li-ion batteries. 12 Wh/kg vs. 150
Wh/kg.

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jessaustin
Is it useful to compare capacitors to batteries in this fashion? It's not as
though you could swap out one for the other, in pretty much any realistic
application.

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matthiasl
The hardware I work with uses a supercap to keep the real-time clock going
during power failures. Previously, button cells were used for that.

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nether
whenever the headline is a question, its answer is probably "no"

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personjerry
Could this comment be right?

