Will Lithium-Air Battery Rescue Electric Car Drivers From 'Range Anxiety'?

http://www.nytimes.com/cwire/2010/05/07/07climatewire-will-lithium-air-battery-rescue-electric-car-37498.html?scp=1&sq=GM%20lithium&st=cse

Forecasting a 10-20 year development timeframe, but with adoption of Li-Ion-powered EVs the amount of money that would line up behind this research could cut that in half.

:applause:

with a graph showing theoretical energy densities:



By comparison, a current-generation Li-Ion battery has an energy density of about 150 Wh/kg.

However make sure to keep theoretical and practical separate.

You provided real world numbers for LithiumIon (150Wh to 250Wh per kg) and theoretical max for Lithium Air. For comparison the theoretical energy density of Lithium Ion depends on what cathodes and anodes are used but ranges from about 500Wh per kg to about 2500 Wh per kg.

This illustrates that we haven't even mastered the true potential of LithiumIon. It is unlikely the first (or even 5th) generation LithiumAir batteries would get even close to 100% of theoretical energy density.

Still LithiumAir has two advantages when it comes to density. The first is that air well technically oxygen (anode) has very low density thus that roughly doubles the energy density compared to "densest" lithiumIon batteries.

The second (second column) is that the air doesn't need to be stored in the battery. The battery would simply breathe (pulling oxygen from air as needed) and that further doubles density.

So if LithiumAir engineering is roughly equivelent to LithiumIon we could expect a 4 fold increase in energy density. However the larger issue is cost. The Tesla Roadster shows that a large battery pack is possible in vehicle the larger limit is cost.

If Lithium Air provides 4x the energy density but at double the cost (per KWh) it won't have much practical use in autos.