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Default Good gawd, Drivel was right, after all.

http://www.upworthy.com/see-the-scie...-battery-l?g=2
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Default Good gawd, Drivel was right, after all.

Grimly Curmudgeon wrote:
http://www.upworthy.com/see-the-scie...-battery-l?g=2


It was claimed that it will be possible to charge a supercap in an
electric car in one minute. I wonder what the current would be, and what
size cables and connectors would be needed. Also I wonder what the
charging station infrastructure would be.

Bill
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On 17/02/2013 00:25, Grimly Curmudgeon wrote:

http://www.upworthy.com/see-the-scie...-battery-l?g=2


Dribble as usual was extrapolating too far without actually thinking
through the implications.

While a high capacity super cap would be good new for all sorts of
electronic gadgets, it would simply bring a different problem should you
apply it to (longer range) transport.

If you have a 50kWh battery and want to charge it, what charge rate do
you need to use to charge it in a minute (or even ten)?



(there are actually some even more interesting developments using hybrid
LiPoly batteries with carbon nano tubes to increase capacity)




--
Cheers,

John.

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Default Good gawd, Drivel was right, after all.

On Sun, 17 Feb 2013 00:25:59 +0000, Grimly Curmudgeon
wrote:

http://www.upworthy.com/see-the-scie...-battery-l?g=2


Second one as well. Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.
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On 17/02/13 01:38, Bill Wright wrote:
Grimly Curmudgeon wrote:
http://www.upworthy.com/see-the-scie...-battery-l?g=2


It was claimed that it will be possible to charge a supercap in an
electric car in one minute. I wonder what the current would be, and what
size cables and connectors would be needed. Also I wonder what the
charging station infrastructure would be.

Bill

of course its possible. The car would get about 3 miles on it though.

And imagine shorting it..


--
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(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.



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On 17/02/13 02:51, John Rumm wrote:
On 17/02/2013 00:25, Grimly Curmudgeon wrote:

http://www.upworthy.com/see-the-scie...-battery-l?g=2


Dribble as usual was extrapolating too far without actually thinking
through the implications.

While a high capacity super cap would be good new for all sorts of
electronic gadgets, it would simply bring a different problem should you
apply it to (longer range) transport.

If you have a 50kWh battery and want to charge it, what charge rate do
you need to use to charge it in a minute (or even ten)?



(there are actually some even more interesting developments using hybrid
LiPoly batteries with carbon nano tubes to increase capacity)


NOT to increase capacity. To decrease internal resistance. faster
charging, no more miles per charge.






--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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On 17/02/13 03:46, Ericp wrote:
On Sun, 17 Feb 2013 00:25:59 +0000, Grimly Curmudgeon
wrote:

http://www.upworthy.com/see-the-scie...-battery-l?g=2


Second one as well. Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.

No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.

People are so easy to mislead where green things are concerned.

--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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The Natural Philosopher wrote:

John Rumm wrote:

there are actually some even more interesting developments using hybrid
LiPoly batteries with carbon nano tubes to increase capacity


NOT to increase capacity. To decrease internal resistance. faster
charging, no more miles per charge.


3x the capacity, 10 minute charging time ... still in the research labs.

http://scitechdaily.com/new-lithium-ion-battery-design-uses-silicon-nanoparticles


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The Natural Philosopher wrote:

On 17/02/13 03:46, Ericp wrote:

Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.


No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.


Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).

[Sorry the links are images, the Nano Research journal is dumb enough to
think they can charge £30 for access to their online articles while
giving a free peek at the first page]

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/000.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/001.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/002.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/003.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/004.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/005.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/006.png

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/007.png

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On 17/02/2013 08:14, Andy Burns wrote:
The Natural Philosopher wrote:

On 17/02/13 03:46, Ericp wrote:

Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.


No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.


Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).

[Sorry the links are images, the Nano Research journal is dumb enough to
think they can charge £30 for access to their online articles while
giving a free peek at the first page]


They're even dumber than that actually: have a free pdf file:
http://www.thenanoresearch.com/upload/justPDF/0293.pdf

--
David


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On 17/02/2013 09:46, Lobster wrote:
On 17/02/2013 08:14, Andy Burns wrote:
The Natural Philosopher wrote:

On 17/02/13 03:46, Ericp wrote:

Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.

No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.


Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).

[Sorry the links are images, the Nano Research journal is dumb enough to
think they can charge £30 for access to their online articles while
giving a free peek at the first page]


They're even dumber than that actually: have a free pdf file:
http://www.thenanoresearch.com/upload/justPDF/0293.pdf


.... oh, actually to be fair on the publisher, that's deliberately free:

"Tsinghua University Press (TUP) provides Just Accepted as an optional
and free service which allows authors to make their results available to
the research community as soon as possible after acceptance. After a
manuscript has been technically edited and formatted, it will be removed
from the Just Accepted Web site and published as an ASAP article."

--
David
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I think the answer has to be 'very large'

Brian

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"Bill Wright" wrote in message
...
Grimly Curmudgeon wrote:
http://www.upworthy.com/see-the-scie...-battery-l?g=2


It was claimed that it will be possible to charge a supercap in an
electric car in one minute. I wonder what the current would be, and what
size cables and connectors would be needed. Also I wonder what the
charging station infrastructure would be.

Bill



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On 17/02/2013 06:31, The Natural Philosopher wrote:
On 17/02/13 02:51, John Rumm wrote:
On 17/02/2013 00:25, Grimly Curmudgeon wrote:

http://www.upworthy.com/see-the-scie...-battery-l?g=2



Dribble as usual was extrapolating too far without actually thinking
through the implications.

While a high capacity super cap would be good new for all sorts of
electronic gadgets, it would simply bring a different problem should you
apply it to (longer range) transport.

If you have a 50kWh battery and want to charge it, what charge rate do
you need to use to charge it in a minute (or even ten)?



(there are actually some even more interesting developments using hybrid
LiPoly batteries with carbon nano tubes to increase capacity)


NOT to increase capacity. To decrease internal resistance. faster
charging, no more miles per charge.


That statement seems mutually contradictory...

Even just a reduction in internal resistance would make more of the
stored energy usefully available, and result in less dissipation in the
cell itself.

However what I was reading also suggested an increase in capacity as well:

http://www.scientificamerican.com/ar...ithium-battery


--
Cheers,

John.

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|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
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Default Good gawd, Drivel was right, after all.

On Sunday, February 17, 2013 12:25:59 AM UTC, Grimly Curmudgeon wrote:
http://www.upworthy.com/see-the-scie...-battery-l?g=2


Where is Drivel? He hasn't been around recently. Sectioned? Dead? Recovered?
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On 17/02/13 07:50, Andy Burns wrote:
The Natural Philosopher wrote:

John Rumm wrote:

there are actually some even more interesting developments using hybrid
LiPoly batteries with carbon nano tubes to increase capacity


NOT to increase capacity. To decrease internal resistance. faster
charging, no more miles per charge.


3x the capacity, 10 minute charging time ... still in the research labs.

http://scitechdaily.com/new-lithium-ion-battery-design-uses-silicon-nanoparticles



If you chase the source down, it really isn't some super breakthrough,
its just about getting all that can be got out of lithium. I.e. instead
of approximately 30-40% of theoretical power and energy density from
cheap batteries made with various anodes, they can get nearer the real
theoretical limits. So maybe a factor of two on energy density and
several times higher on power density. Befoire you wrarp the battery in
a crashproof safety housing.


When I did the calculations of leccycars about 4-5 years ago, I realised
that the batteries I was able to source for models were about 3 times
heavier than the theory said the should be. However even a 3 times
lighter battery wasn't going to make cars with 600 mile ranges
practicable, or cheap.

This might in ten years mean you have a 150 mile car, instead of a 50
mile car, that costs £15,000, instead of £30,000 and actually does 200k
miles on one battery before its ****ed.






--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.



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On 17/02/13 08:14, Andy Burns wrote:
The Natural Philosopher wrote:

On 17/02/13 03:46, Ericp wrote:

Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.


No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.


Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).


compared with carbon electrodes. But I have never seen carbon electrodes
in any battery its been my misfortune to destroy.

And plenty of other people are getting better than that using other ways:

http://en.wikipedia.org/wiki/Lithium-ion_batteries


Note about twice the energy density of this 'new' research using ..air!.

Something is missing, because lets say that standard today technology is
capable of say 1Ah/gm at 3.7v That's 3.7watt hours per gram, or 3.7kwh
hours per kilogram, or 37kwh per 10kg. So an EXISTING car better ought
to be around 10kg!! No WAY is ANY commercial lithium battery anything
LIKE that.

e.g. an uncased pack of lithium cobalt technology

http://www.hobbyking.com/hobbyking/s...po_ Pack.html

gets around 25watt hours in 200 grams.

so about 125 watt hours per kilogram. A factor of at least 10, possibly
37 ...different from these 'claims'

So something is not adding up.

milliampere hours per gram is not power density and its not energy
density. Its current density, and something is not making sense here.


viz "At the meeting, Au said that his research group has demonstrated a
coin-sized rechargeable lithium-air battery with a current density of
600 mAh/g, which is much higher than the current densities of 100 to 150
mAh/g of lithium-ion batteries.

Read more at:
http://phys.org/news/2011-02-lithium-air-batteries-high-energy-density.html#jCp"


But again, without knowing what the terminal voltage is, its impossible
to know what the energy density is.


My 'what a BEV needs' boil down top at least 200Kwh in a battery
weighing no more than 200kg. That should give you an all day driving
sort of range. So a watt hour per gram essentially. For the complete
battery.

current state of the model world batteries are achieving an eighth of that.

Nickel probably less than 1/15th of that.

The world is full of wonderful claims that are couched in terms that
hide the actuality.

I have no doubt these guys have done good research, but by starting from
a **** poor place and using terms that don't mean much in the real
world, its hard to see that the claims amount to much.

As I said, current batteries are about 8 times worse than they need to
be. Even if these are three times better, its still not good enough.

And the question remains. Three times better than what, and in what way?


http://wiki.xtronics.com/index.php/Energy_density

is worth a read.
Petrol 12,200 Wh/kg So at 30% efficiency that's still around 4Kwh per kg.

Lithium ion 130 - 1200 Wh/kg Even at 90% efficiency that's not cutting
the mustard. And nowhere have I seen a 1.2Kwh/kg battery. The lower
figure of around 130Wh per kg is more like what's around.







[Sorry the links are images, the Nano Research journal is dumb enough to
think they can charge £30 for access to their online articles while
giving a free peek at the first page]

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/000.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/001.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/002.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/003.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/004.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/005.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/006.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/007.png



Read em all and still no answers.




--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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On 17/02/13 09:46, Lobster wrote:
On 17/02/2013 08:14, Andy Burns wrote:
The Natural Philosopher wrote:

On 17/02/13 03:46, Ericp wrote:

Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.

No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.


Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).

[Sorry the links are images, the Nano Research journal is dumb enough to
think they can charge £30 for access to their online articles while
giving a free peek at the first page]


They're even dumber than that actually: have a free pdf file:
http://www.thenanoresearch.com/upload/justPDF/0293.pdf

Much better. Now try searching on the all important word 'voltage'

"The voltage range is set to 0.012.0 V"

is The ONLY mention of voltage with an actual NUMBER and hence power,
and energy, at all!


needless to say 4 ampere hours per gram at 0.01 volts is not exactly a
huge energy density. but 2v - 8 watt hours per gram - would have
investors leaping for their chequebooks. 8 kilowatts per kilogram is an
800Kwh per tonne battery.

That's a 110bhp (average) 30 tonne truck all day!

I see no investors leaping for their chequebooks. Ergo I conclude there
is something more here than meets the eye.


--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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On 17/02/13 11:26, Brian Gaff wrote:
I think the answer has to be 'very large'

Brian

work on a tank of fuel being a couple of hundred kwh in electrical
terms. 200kwh in 1/60th of an hours is 12MW.

So about 13,000 amps at 240V..

Of course the supercap is only enough to get you five miles.. so
probably about 130 amps

realistically it should be possible to supply those sorts of peak loads
at 'filling stations' but it wont be easy..or cheap.


--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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On 17/02/2013 13:49, The Natural Philosopher wrote:
On 17/02/13 11:26, Brian Gaff wrote:
I think the answer has to be 'very large'

Brian

work on a tank of fuel being a couple of hundred kwh in electrical
terms. 200kwh in 1/60th of an hours is 12MW.

So about 13,000 amps at 240V..

Of course the supercap is only enough to get you five miles.. so
probably about 130 amps

realistically it should be possible to supply those sorts of peak loads
at 'filling stations' but it wont be easy..or cheap.


But if the recharge station itself has mega-super-caps that it charges
up relatively slowly, then the delivery of power to the charging station
might be very achievable.

(Can't help thinking that filling stations canopies represent a huge
area desperate to be populated by solar cells. Though being built
next-door to nuclear power stations would be more likely to fulfill the
electricity requirement.)

--
Rod
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On 17/02/13 12:34, John Rumm wrote:
On 17/02/2013 06:31, The Natural Philosopher wrote:
On 17/02/13 02:51, John Rumm wrote:
On 17/02/2013 00:25, Grimly Curmudgeon wrote:

http://www.upworthy.com/see-the-scie...-battery-l?g=2




Dribble as usual was extrapolating too far without actually thinking
through the implications.

While a high capacity super cap would be good new for all sorts of
electronic gadgets, it would simply bring a different problem should you
apply it to (longer range) transport.

If you have a 50kWh battery and want to charge it, what charge rate do
you need to use to charge it in a minute (or even ten)?



(there are actually some even more interesting developments using hybrid
LiPoly batteries with carbon nano tubes to increase capacity)


NOT to increase capacity. To decrease internal resistance. faster
charging, no more miles per charge.


That statement seems mutually contradictory...

Even just a reduction in internal resistance would make more of the
stored energy usefully available, and result in less dissipation in the
cell itself.


Not significantly. WE get about 20% capacity loss from the 10 hour rate
with models draining them in 5-10 minutes. travelling for a couple of
*hours* they are already as good as they need to be.

The key things is *recharge* losses when being banged full of electrons
in a hurry. They get hot and that's where you lose power and edge up
towards 'unsafe'..

realistically a safe if not especially efficient charge is 20 minutes or
so on existing technology.

I've seen prototypes quotes as being safe for 5 minutes.


However what I was reading also suggested an increase in capacity as well:

http://www.scientificamerican.com/ar...ithium-battery



Boost of power is not boost of capacity.

As I said, power is not that hard. model aircraft batteries are edging
towards at 3 minute discharge times something like a horsepower per
pound weight, or more.

giving an overall performance level with airframe and motors stuff of
around 500bhp-800bhp per tonne. Which is formula one (fuelled up)
levels of performance. The problem is that its a wild ride, but it only
lasts a couple of minutes.







--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.



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On 17/02/13 13:57, polygonum wrote:
On 17/02/2013 13:49, The Natural Philosopher wrote:
On 17/02/13 11:26, Brian Gaff wrote:
I think the answer has to be 'very large'

Brian

work on a tank of fuel being a couple of hundred kwh in electrical
terms. 200kwh in 1/60th of an hours is 12MW.

So about 13,000 amps at 240V..

Of course the supercap is only enough to get you five miles.. so
probably about 130 amps

realistically it should be possible to supply those sorts of peak loads
at 'filling stations' but it wont be easy..or cheap.


But if the recharge station itself has mega-super-caps that it charges
up relatively slowly, then the delivery of power to the charging station
might be very achievable.

(Can't help thinking that filling stations canopies represent a huge
area desperate to be populated by solar cells. Though being built
next-door to nuclear power stations would be more likely to fulfill the
electricity requirement.)

Actually the way I would do it is big **** off mechanical converters
containing loads of rotational energy.

I flew once in a research plane of Decca's. Massive rotary inverters
powering the kit 'why do you not use transistorised inverters?' 'Well we
tried. And when they pulled the gear up, it all stopped for 15 seconds'

:-)

Supercaps are nowhere near good enough yet. And the thing that makes em
so fast charging - very low resistance - also makes them bloody
dangerous. Imaging a screwdriver through a supercap with a few kwh of
energy in it. You are talking serious amounts of TNT equivalent.at least
a kg.

Blow your bloody doors off!



--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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Default Good gawd, Drivel was right, after all.

On 17/02/13 08:14, Andy Burns wrote:
The Natural Philosopher wrote:

On 17/02/13 03:46, Ericp wrote:

Uni of California announced they stuffed nanotubes
in a lithium battery and found it lasted longer, held three times as
much and charged in ten minutes.


No,. they didn't. read the thing carefully. It had three times the POWER
density, not three times the ENERGY density.


Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).


at what voltage though. 3 times the mah is not much point if the cell
voltage drops a factor of 3 :-) I can do you a lot of mah per gram in a
2v battery.. :-)



[Sorry the links are images, the Nano Research journal is dumb enough to
think they can charge £30 for access to their online articles while
giving a free peek at the first page]

http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/000.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/001.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/002.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/003.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/004.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/005.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/006.png


http://link.springer.com/static-content/0.6134/lookinside/935/art%253A10.1007%252Fs12274-013-0293-y/007.png




--
Ineptocracy

(in-ep-toc-ra-cy) a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

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Default Good gawd, Drivel was right, after all.

On 17/02/2013 13:49, The Natural Philosopher wrote:
On 17/02/13 11:26, Brian Gaff wrote:
I think the answer has to be 'very large'

Brian

work on a tank of fuel being a couple of hundred kwh in electrical
terms. 200kwh in 1/60th of an hours is 12MW.

So about 13,000 amps at 240V..


Only 13A at 240 kV though!

(smiles at the thought)

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Default Good gawd, Drivel was right, after all.

Onetap wrote:

Where is Drivel? He hasn't been around recently. Sectioned? Dead? Recovered?


As a matter of irrelevance, an elderly friend of mine who sadly
developed dementia has gone for a year with the NHS refusing to pay for
his care. On investigation it turns out that he was down as having been
sectioned and consequently they assumed he was in a special care home
where charges go automatically to the NHS. In fact he has been in a
private care home, at great cost to the family. There's now a barney
going on about reimbursement.

They thought he'd been sectioned because he very nearly was, a year ago,
when he was playing up rather a lot and wouldn't take his meds or leave
his home to go to hospital.

Bill
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Default Good gawd, Drivel was right, after all.

newshound wrote:

The Natural Philosopher wrote:

work on a tank of fuel being a couple of hundred kwh in electrical
terms. 200kwh in 1/60th of an hours is 12MW.
So about 13,000 amps at 240V..


Only 13A at 240 kV though!


Simples ... convert all pylons next to roads into charge stations :-)



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The Natural Philosopher wrote:

On 17/02/13 08:14, Andy Burns wrote:

Yes, they *are* talking about 3x energy density in milliamp hours per
gram (as well as discussing charge rates in amps per gram).


at what voltage though.


Seems the common 3.7V flavour of Lithium ion batteries
are lithium nickel manganese cobalt oxide cathode with graphite anodes

3 times the mah is not much point if the cell
voltage drops a factor of 3 :-)


Sure. I've been trying to see what effect they say substituting a
silicon anode for a graphite one would have on battery voltage, I think
the graphite anodes are "inactive" within the the normal 3.7V Li-ion
battery chemistry, so perhaps none at all.

They do sprinkle in encouraging phrases such as "no significant effect
on the battery working voltage" but I daresay the chemistry of
rechargeable Lithium cells is well beyond schoolboy Zn/Cu red-ox equations.

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