how does everything work

The graphite particles that make up the cathode are applied to one side of the paper strip. On the other – zinc, which allows you to create an anode. In both cases, a special paint is used. To start the battery, you just need to drop a few drops of water on the paper, after which the salt dissolves and the redox reaction begins, thanks to the ionic conductivity.

Zinc will oxidize and begin to release electrons. If you connect a charge to the contacts, the electron flow will go to the cathode, where a reduction reaction will take place using oxygen. So it will actually be an ordinary battery. As stated, the process will continue until the water dries up or the zinc supply is depleted.

How long would such a battery last?

Regarding power, the no-load voltage will be 1.2 V during the first soak and 0.5 V during the second soak. In both cases the battery operated for an hour. It is also stated that the battery can power the electronic alarm clock for about an hour.

Battery powered the clock for one hour / Photo by ScienceDaily

So far, the solution has problems. For example, we need to find a way to prevent the battery from drying out prematurely, but it’s purely engineering anyway. There is no information yet about the commercial launch of the production of such batteries, but scientists believe that they will find use as backup power sources.