Re: Batteries


"B Richardson" <brich@xxxxxxxxxxxx> wrote in message news:g5ovc001kh9@xxxxxxxxxxxxxxxxxxxxx
["Followup-To:" header set to sci.energy.]
On 2008-07-16, Rob Dekker <rob@xxxxxxxxxxx> wrote:

"Rob Dekker" <rob@xxxxxxxxxxx> wrote in message
news:g5kec9$km0$1@xxxxxxxxxxxxxxxxxxx
...
Again, I dispute that 50% efficiency difference number, and I think it is
closer to 25%, which would be only 140 thousand to lithium per year. And
that does not even account for the energy loss to go from crude to
gasoline.


And did I mention the 30% improvement because of regenerative braking ?
(which is not part of the 25% ICE efficiency of the Honda's you mention) ?

We are now at 100 thousand ton of lithium per year.
Now that's something we can live with right ?


Some lithium supply speculation,

http://www.evworld.com/library/lithium_shortage.pdf



That is a very interesting report. Thanks !

I like their analysis. It seems that if all 60 million cars per year would be equipped with lithium-ion batteries, then we would
have a very hard time mining enough of the material.
However, this assuming that lithium batteries won't make much progress : it is based on an assumption of 0.3 kg lithium metal/ kWh.

The theoretical limit (for 2V cells) is 0.13 kg/kWh (7.6 kWh/kg) (see side thread).
New anode (silicon nanowire?) and cathode (sulfur?) design would bring lithium use very close to this theoretical minimum.
That makes the problem a factor 2.2 less severe, and lithium mining for reasonable price is then probably managable.
A 30 kWh lithium-derivative battery would then only use 4 kg lithium metal. For such optimal batteries, unless lithium prices reach
close to $1000/kg, lithium will not be a major cost item in EV battery production. And I'm sure that Bolivia will be very willing to
cooperate (mining their lithium carbonate salt fields) with lithium prices at such levels.

Still, I agree that lithium would probably not be the ONLY choice for wide-scale use of low-cost EVs.
It's a good thing that there are many other options (Zebra's and Zi-air is what they mention) for low-cost high-performance
batteries.

Thanks again !

Rob



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