Researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa) have invented a biodegradable battery that is printed onto paper. The paper battery could revolutionise single-use electronics, and it turns on with droplets of water.
We are using electronics for more things than ever before. Our increased use of technology has a huge environmental effect, especially with battery technology. Batteries that are sent to landfill can release toxic chemicals into the ground, such as mercury, cadmium, lead and nickel, which has detrimental effects on our water supply.
It is also estimated that our use of batteries will increase 11 fold between 2020 and 2030. At the same time our reliance on single use micro-devices is set to expand dramatically within the next decade. The Empa battery has the potential to decrease the environmental toll of batteries, particularly on single-use devices. So how does it it work?
How The Battery Works
The battery is printed using a modified 3D printer which prints the battery using their recipe of carbon, cellulose, glycerin and table salt.
When water is added, the salt dissolves and releases charged ions. At the negative terminal, the ions make come into contact zinc causing it to oxidise- essentially causing it to rust, and release electrons.
The battery can store electricity for hours, and has been used to power a small digital clock in a prototype.
The battery can withstand thousands of charge and discharge cycles, be stored for years without use, as well as survive in freezing temperatures. It is also shock and pressure resistant.
When you no longer need the battery, it can be simply popped into a compost bin. Within two months it will have completely broken down.
Gustav Nyström from Empa says,
“The project of a biodegradable electricity storage system has been close to my heart for a long time. We applied for Empa internal funding with our project, Printed Paper Batteries, and were able to start our activities with this funding. Now we have achieved our first goal.”
Powering The Internet of Things
The battery could help revolutionise how some Internet of Things devices are powered. Nyström says,
“In the future, such capacitors could be briefly charged using an electromagnetic field, for example, then they could provide power for a sensor or a microtransmitter for hours.”
For instance, the paper battery could power a tracker on a package or be used to power devices that monitor the environment. Instead of needing to be collected again could be left to naturally breakdown in nature.
Another field Nyström sees the devices being used is in the medical field, with small single-use test devices such as blood glucose monitors, or constant glucose monitors for diabetics.