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Re: [EVDL] The Zinc Air Battery

Zinc-air is a primary (non-rechargeable) battery. Some people call them a
variant of fuel cells - because they have to be replaced or "refueled" with
new or reclaimed zinc.

Aluminum can also be used. ALCAN was involved in such an EV project with
Unique Mobility about 15 years ago.

I haven't yet read an analysis of the electrical efficiency of these
batteries. I suspect that reducing zinc oxide or aluminum oxide to metallic
zinc is going to take a LOT of energy.
David Roden - Akron, Ohio, USA
EVDL Administrator

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Re: [EVDL] The Zinc Air Battery

 

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Re: [EVDL] The Zinc Air Battery

On 23 Oct 2007 at 15:39, R Patterson wrote:

> Not to mention aluminum oxide is a nasty toxic compound. What acts as the
> opposing electrode in this type of battery?

It's the air!

http://en.wikipedia.org/wiki/Aluminium_battery

http://www.corrosion-doctors.org/Batteries/al-air.htm

http://www.exo.net/~pauld/activities/AlAirBattery/alairbattery.html

Perhaps 10 years ago, the German Post Office undertook a test of several EVs
using Zinc-air batteries. The system, which was developed by the company
Electric Fuel company in Israel, used zinc "cassettes." I seem to recall
some rather promising range results.

AFAIK this trial ended with no further development. I did a quick search
just now and found a report which says, "the technology ultimately failed to
deliver sufficient reliability and economy for routine fleet operations."

I got the impression that Unique Mobility's tests with Al-Air batteries were
not especially successful, either. I recall that one problem was that while
the batteries had good specific energy, their specific power was low. The
test mules needed lead batteries to provide enough power for acceleration.

As for efficiency, I found a Sandia Labs document which discusses this
matter for Zn-Air batteries :

http://www.prod.sandia.gov/cgi-bin/techlib/access-control.pl/1994/942047.pdf

There I find : "The coulombic efficiency for secondary zinc/air batteries is
currently in the range of 55 - 60%. Westinghouse cells were measured at 55%
coulombic efficiency. Overall battery energy efficiency, when considering
auxiliary pumps and humidity controls, may be limited to 60%."

They report the specific energy of Zn-Air batteries as on the order of 150 -
250 Wh/kg. This is quite good. A good lead battery can achieve about 35
Wh/kg.

David Roden
EVDL Administrator
http://www.evdl.org/


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Re: [EVDL] The Zinc Air Battery

On 23 Oct 2007 at 15:39, R Patterson wrote:

> Not to mention aluminum oxide is a nasty toxic compound. What acts as the
> opposing electrode in this type of battery?

It's the air!

http://en.wikipedia.org/wiki/Aluminium_battery

http://www.corrosion-doctors.org/Batteries/al-air.htm

http://www.exo.net/~pauld/activities/AlAirBattery/alairbattery.html

Perhaps 10 years ago, the German Post Office undertook a test of several EVs
using Zinc-air batteries. The system, which was developed by the company
Electric Fuel company in Israel, used zinc "cassettes." I seem to recall
some rather promising range results.

AFAIK this trial ended with no further development. I did a quick search
just now and found a report which says, "the technology ultimately failed to
deliver sufficient reliability and economy for routine fleet operations."

I got the impression that Unique Mobility's tests with Al-Air batteries were
not especially successful, either. I recall that one problem was that while
the batteries had good specific energy, their specific power was low. The
test mules needed lead batteries to provide enough power for acceleration.

As for efficiency, I found a Sandia Labs document which discusses this
matter for Zn-Air batteries :

http://www.prod.sandia.gov/cgi-bin/techlib/access-control.pl/1994/942047.pdf

There I find : "The coulombic efficiency for secondary zinc/air batteries is
currently in the range of 55 - 60%. Westinghouse cells were measured at 55%
coulombic efficiency. Overall battery energy efficiency, when considering
auxiliary pumps and humidity controls, may be limited to 60%."

They report the specific energy of Zn-Air batteries as on the order of 150 -
250 Wh/kg. This is quite good. A good lead battery can achieve about 35
Wh/kg.

David Roden
EVDL Administrator
http://www.evdl.org/


_______________________________________________
For subscription options, see
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Re: [EVDL] The Zinc Air Battery