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If it works
By bobsmith1492 on 10/30/2009 3:40:48 PM , Rating: 2
This could be an amazing breakthrough.

According to the Handbook of Batteries, zinc-air has a theoretical energy density of 415mWh/g or 1450 Wh/L. Li-ion exhibits energy density of 160mWh/g or 430Wh/L.

So, zinc-air is both lighter and more dense than Li-ion cells by approximately 3 times, as the article states.

However, this is comparing a secondary (rechargeable) Li-ion with a primary zinc-air since there was no rechargeable zinc-air available when the book was written. So, it remains to be seen how much impact the addition of the charge mechanism has on the energy density of the cells.

Zinc air will also be sensitive to the operating environment air. It remains to be seen which air impurities may affect the lifespan of rechargeable cells; I don't see any information about that in the handbook.

Regarding performance at altitude, there is a plot showing the impact of extra air holes in existing hearing aid zinc-air cells; basically once there is a certain amount of air available, the output current is relatively constant. So, if cells are designed with more than enough air flow, any reasonable altitude should show no change.

Temperature is another consideration; all chemical processes slow with temperature so I'm sure output will drop when it's cold.

