Nanotubes break records for supercapacitor performance:

http://www.news.ucdavis.edu/search/news_detail.lasso?id=7287

Will this finally make electric cars economical? Will batteries go
obsolete?

On 16 Feb 2005 04:52:24 GMT, manof...@yahoo.com wrote:

"Could be manufactured from carbon nanotubes"

sounds awfully speculative to me.

"Hybrid-electric and fuel-cell powered vehicles need such a surge of
energy to start, more than can be provided by regular batteries"

Haven't these guys heard that Toyota and Honda are already making
hybrids, and that they actually start?

The best available supercap is still about three or more orders of
magnitude less energy-dense than a decent battery, and maybe 5 orders
less dense than a tank of gasoline.

John

Oh, c'mon, John.  Sounds like you didn't bother to read the article.
I did.  It's "awfully speculative," yes, in the sense that these
things aren't on the shelves or might not take off due to the vagaries
of market capital.  But, having read the paper, I can say that it's
not as speculative as you're trying to make it sound.

The paper isn't an idea paper, it's an experimental results paper.
That means Du, et al., actually went and built the damned thing in the
fabrication lab, walked it down the hall to the test lab and measured
it with the favorable results reported therein.

(On the other hand, no, they're not going to replace batteries.
That's just silly.)

--
John S. Novak, III              j...@cegt201.bradley.edu
The Humblest Man on the Net    

It is actually a capacitor where the electrodes are made from films
consisting of nanotubes. The attractive properties of the film are the
contact surface area and high conductivity of the nanotubes taken
collectively, rather than individually.

On 18 Feb 2005 04:22:52 GMT, j...@panix.com (John S. Novak, III) wrote:

Well, most of it.

Or to the laws of Physics, which can be almost as demanding.

Two issues:

1. Seems that every researcher who makes some obscure measurement
includes wild speculation on applications, the favorites being a
breakthrough in energy production or a cure for cancer. I think they
do it to get publicity for work that nobody would otherwise notice.

2. Electrostatic energy storage will *never* approach chemical storage
in energy density or cost, by orders of magnitude. That's wired into
the physics.

So if they'd left out the silly speculation, their paper would be more
"scientific."

Consider how many energy/cancer/nanofab breakthroughs have been
celebrated in this ng alone in the last few years. And then consider
how many have progressed to within telescope range of being practical.
It's not a pretty sight.

John

No, I mean the article, not the press release.  The IOP leaves its
articles open for the first thirty days of their publication.  Since I
wanted to see what had you all riled up, I went and actually read it.

Did you?

If you have a substantive complaint against the results of the
article, make it.  At present, all you're doing is engaging in fear,
uncertainty and doubt, using sarcasm and indirectness as tactics.

Again, I can only encourage you to read the paper.  

First, The paper makes no claims about breakthrough processes in
energy production.  Capacitors don't produce energy, they store
energy, and nothing in the paper gives any other impressions.  
Even more narrowly, this is an improved technique in energy transfer,
since the paper describes a very high tech method for dealing with
a very basic electrical problem-- the equivalent series resistance
(ESR) of capacitor terminals.

Second, the paper makes no claims that this or any other technique
will result in electrostatic storage with greater energy density than
chemical storage.  It's just not there.

Third, having read both the press release *and* the paper, I can see
where there might be some confusion.  The press release makes
unsubstantiated claims about fuel cells and the like, but that's
simply not in the paper, and is probably the result of either the
authors being taken out of context, being misunderstood, or the
university publicist groping for a gee-whiz application.  But it's not
in the paper.

Except, er, that's not in the paper.  The boldest claim you'll find in
the paper is in the conclusion:  "...[T]his is an attractive approach
to fabricate electrodes for supercapacitors of high power density."

So, having said all that, I must ask again:  Did you read the paper?
Or just the press release?

--
John S. Novak, III              j...@cegt201.bradley.edu
The Humblest Man on the Net