Title is highly misleading. The battery works by oxidizing Aluminium. So you actually recharge it by replacing Aluminium oxide with elemential Aluminium, which involves melting down the old battery and using electrolysis to seperate Aluminum from Oxygen.
I have not yet seen any estimate about the energy efficiency, but I doubt it is very good. This may be good as a emergency battery.
Yes, the title could have been better, but it's the first sentence of
the article, and the original title of the article was even worse. I'll
try to submit something better on the same topic tomorrow.