I think the general idea is that you have a lithium battery for the typically shorter day to day journeys (say 60 miles?), and the air battery is there for occa

I think the general idea is that you have a lithium battery for the typically shorter day to day journeys (say 60 miles?), and the air battery is there for occasional long-range journeys. This amounts to a different solution for the problem that the Volt solves - with substantially lower weight/cost/maintenance overhead.