Yeah 5000 of them to get the 500 mW a smartphone needs in standby mode. 50000 if you want to power up the phone from stabdby (assuming it just uses 5 Watts)
It is the article that mentioned smart phones which is bullshit. This is a (probably expensive) battery specialized for extremely low power devices which need to run for many years. It will never be something that powers your phone.
The tech is really cool and there's applications for such a battery - just not phones.
A lot of sensors/gauges in industrial applications are retrofitted with lorawan or similar remote readout capabilities right now. Battery life for these devices is already a big design consideration, especially since not all locations are easily accessible.
With a power source like this you would essentially charge a capacitor, use the stored charge to do a sensor read and short data burst, and then wait for the next charge.