
Scientists develop lithium-ion battery that charges 120 times faster than normal - evo_9
http://www.extremetech.com/extreme/134635-scientists-develop-lithium-ion-battery-that-charges-120-times-faster-than-normal
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cagenut
This is like my gimmick at this point every time there's an extremetech.com
battery article...

Here is the much better/more-detailed article at GCC:
<http://www.greencarcongress.com/2012/08/cho-20120816.html>

To me the interesting part isn't that it charges so fast, there have been LTO
chemistries that charge plenty-fast for a while, but that its density is
nearly double. We're now seeing multiple labs and vendors producing 300 - 400
wh/kg results. Expectations even just a few years ago were that we'd only be
in the 250 range by now (where tesla is at).

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ChuckMcM
Every time I see a headline like this I sigh and think, now it would be news
if a _manufacturer_ developed a lithium-ion battery with this charge rate.
Because of course the difference between 'proof of concept' and 'product' is
sometimes an uncrossable chasm.

That said, the article does point out the challenge of sending 56kWH to charge
a Tesla in 1 minute. In case you are wondering that is a 3.36MW power draw for
one minute. I can assure you that if we have an easy way to make stations that
can deliver 3.3MW continuously for a minute at a time that the future of laser
weapons is extremely bright (pun intended).

Now charge your phone or laptop in a minute, very cool. Too bad that the it
makes the unit 3x thicker.

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ars
Just to give some numbers here: Assuming 600 volts (which is the highest
rating for voltage I've seen in a commonly available wire) you would be
sending 5600A down that wire.

That would require a wire 2 inches thick (1 inch radius), not including the
insulation. I doubt most people would even be able to lift such a wire.

A 15 foot length would weigh 416 pounds! (Assuming no ground - with a ground
it's 625 pounds.)

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Turing_Machine
Is that the continuous rating, though?

Welding cables for intermittent duty are rated for higher currents, I think.

Yeah, it'd heat up, but it would have plenty of time to cool off in between
charges. You'd need to arrange things so that there was absolutely no way for
the user touch the hot contacts and of course use high-temp insulation
throughout (which welding cables already have).

You'd want a docking station type of arrangement rather than a cable, I'd
think -- maybe with some sort of clamp to really mash the contacts together.
Arcing would be bad. :-)

Certainly you couldn't run it off a normal wall plug. A big capacitor bank,
maybe.

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ars
It's the 90c rating.

Got some new numbers after checking welding cables, looks like 1/2 inch radius
will do, I calculate weight of 128 pounds for 15 feet, which is "better" - but
still completely impractical.

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Turing_Machine
Only if you're using cables. No one would do that. You'd have a solid docking
station with fixed, solid contacts, as I (and the person with the post
immediately above yours) said.

You can use solid, fixed contacts at any temperature that won't melt the
copper (assuming that they're well away from anything flammable).

~~~
ars
You still need cables inside the car. Maybe not 15 feet, but that much weight
is impractical.

If you really wanted to do this the only practical way is to increase the
voltage - but of course high voltage is much harder to do safely.

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tjoff
_Other factors, such as the battery’s energy density and cycle life seem to
remain unchanged._

I might have confused different battery techs but isn't the main issue with
lithium-ion that heat kills it? And that typically the heat generated when
charging is the main thing limiting it's useful life?

If so, claiming that its cycle life remains unchanged seems quite optimistic.

~~~
cagenut
You're right but drawing the wrong conclusion.

The heat that's produced as the battery charges is a byproduct of the
resistance of the chemistry. So when you get a more efficient chemistry it
increases _both_ cycle life and charge rate, they're two symptoms of the same
property. Its a win/win not a tradeoff (although you can still chose to
tradeoff one for the other in your product design).

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jlgreco
I am thinking that the current needed to charge an electric car battery that
fast would likely be far to high for a residential electric system (at least
ones in houses that have already been built).

With those sort of charging times it seems feasible that you could go back to
the "gas station" model though: Pull up, plug in, eat a hotdog, drive away.

~~~
regularfry
There's two ways to tackle that - either stick to the slow overnight charge,
or have a home charging station with a stonking great capacitor bank which
itself recharges slowly while you're out driving.

~~~
femto
Another way:

Have a standardised battery pack, that can see duty in a multitude of
applications, for example: part of a home solar installation, or in a car.
Have a control system that allows multiple batteries to be combined, in a hot
swappable manner, within a single installation.

Advantages:

1) Economies of scale allow lower battery price, since the same pack is used
everywhere.

2) Common form factor allows batteries to be physically swapped (instant
recharge for a car).

3) Redundancy, if one battery breaks, the system can keep working, with
reduced capacity, until a replacement is bought.

4) With the right control system it should be possible to transfer energy
between batteries as required, allowing the car to be charged in-situ from the
house, or the house to take energy from the car, if needed. The car can even
be used to transfer energy from an external source into the domestic setting,
the electrical equivalent of an oil tanker.

5) More efficient use of available capacity, by combining all batteries into a
single system, they will be used more often, rather than sitting unused while
people sleep or drive.

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anusinha
I believe this is the citation referenced. [1] It's unfortunately under a
paywall.

[1]:
[http://onlinelibrary.wiley.com/doi/10.1002/anie.201203581/ab...](http://onlinelibrary.wiley.com/doi/10.1002/anie.201203581/abstract)

