You have to follow the link to Design News to get to the "money quote":
Aluminum-air also differs from lithium-ion in that it is not rechargeable. That's why the company is suggesting that its batteries be used in a hybrid arrangement, in which drivers would employ lithium-ion on a daily commuting basis, while aluminum-air would serve only on those days when greater range is needed. In such an arrangement, the aluminum-air system would last about a year before needing to be "refurbished" at an unknown cost.
So, great, you're carrying around extra weight every day hoping you'll not need it instead of driving a lighter car with more daily range.
For long range driving this looks to be a good battery to have on an EV. As I understand , there is no recharging time lost, what you need it is topping up the battery with water at regualar intervals during the journey.
I could not understand then why a second Lithium IOn battery is required ?
Why can't the same Aluminium -air battery be used for shorter travel distances? Is the Aluminium- air reaction not stoppable in between ? Can somebody elaborate on this technology?
Exactly! Why use a one time use only battery. This is pure marketing gold for the company but absolute bull shi* for being a practical solution in an EV. Supercaps have more legs then this does. At least with that you can recharge nearly forever. The newer carbon-fibre-graphene matrix supercaps piotentially could offset the lithium type batteries. The old EESTOR ceramic caps touted a few years ago were nothing but marketing and miscalculations.
Yes, I would have enjoyed a bit more specific information regarding the Aluminum-Air battery especially in comparison to lithium iron phosphate (LiFePO4). It seems the Al/air batteries have quite a bit more density from the 300wh/kg in the article to 1000wh/kg and potentially 2000wh/kg vs the 90-110wh/kg for Lithium...
Although the difficulty seems to be in the oxidation of the Aluminum as the Aluminum and electrolyte will react once together so when you start a cell, or cells you will start the oxidation process. There is also some efficiency issues (aluminum degrades to a gel) which it seems they have dealt with already.
I wonder how much engery it takes to reprocess the product of the reaction - thinking about the life cycle of this becoming a common process. I tried to look at how much energy it takes to make alumnum and could not find it, but even after the energy to mine and process the raw material (bauxite) into alumina - significant - they say that in the U.S. alone uses up to 1% of our power to separate the Aluminum from the alumina - 5.25v @ 100K to 150K Amps btw...
Might be worth pointing out that the entire battery does not have to be replaced; only the aluminum anodes and wherever the spent aluminum oxide is stored.
So, at least potentially, this could be an operation not that different from buying a tank of gas "back when". Pull into an equipped service station, the attendant removes the spent anode pack and AlOH3 receptacle (with the help of a purpose-made crane), and replaces them with fresh ones. The removed components get recycled (with the addition of electricity) and used in the next car.
Definitely a different paradigm (are we still allowed to use that word?) but potentially workable I think.
The discussion associated with this article is a wonderful demonstration of the benefits of blog discussions. While the headline promised a new paradigm in electric vehicles, the discussion revealed that the aluminum-air battery is not rechargeable, self discharges, and has an unknown cost. Buying a battery to drive 1,000 miles isn't quite so tempting.