> A lithium-air battery (in general all metal-air batteries) is likely to have lower efficiencies for a complete cycle than other lithium-based batteries, perhaps not much above 80%, if not even less.

This paper directly contradicts this claim with actual measurements of efficiency.

> The energy efficiency of the first cycle was 92.7%, and it gradually dropped to 87.7% after 1000 cycles.

Which is centered just above the 90% mark the person you are replying to gave.