A battery made from paper coated with table salt by Swiss developers has been created that is both environmentally friendly and biodegradable.
To form the anode, graphite particles are deposited one side of the paper strip. You can also create anodes by putting zinc on the opposite side. A special paint is required in both cases. You can start the battery by dropping a few drops water on to the paper. After that, the salt will dissolve in the water and the redox reaction due to ionic conductivity will occur.
Zinc will oxidize which will result in the release of electrons. Connecting a load to the contacts will cause electron flow to go to the cathode. There, an oxygen-based reduction reaction will occur. It will actually be an ordinary battery. The process will continue up to the point that the water runs out or the end of the supply of zinc.
The power of such a lithium-ion battery is 1.2 V without load. The second wetting will give you a voltage of 0.5 V. Both cases last for about an hour. The battery also was capable of powering the electronic alarm clock for approximately an hour.
The solution is not perfect. The solution is still not perfect. For instance, the battery must be kept from drying out before it can be used. This is an engineering problem. Although the commercial launch of these batteries has not been announced yet, scientists believe they will be useful as backup power sources.