NRD claims the battery can deliver power outputs ranging from 5 nanowatts to 500 nanowatts. The device operates within a voltage range of 1.0 V to 20.0 V and a nominal current between 7.5 nA and 33 nA, all within a compact 20 mm by 20 mm by 12 mm form factor.
Ultra low power is an accurate description:
in human terms. how long will it take to charge a phone, and how many times can it be used to charge my phone (total mA hours)
Assuming the upper end for the calculations,
About 37,000 hours
5Ah * 3.7V= 18 Wh
18 Wh/ .0005 W= 37kh
Or about 4.22 years
and it “lasts” over 20 charges (5years per charge) if it lasts 100 years (though it likely doesn’t last 100 years, but has a 100 year half life)
How much can you generate from just ambient radio waves?
Depends on where and how big antenna. Under a power transmission line, lots.
https://en.wikipedia.org/wiki/Energy_harvesting