The Biodegradable Battery
It is expected that the number of data-transmitting microprocessors, for example in packaging and transport logistics, will increase sharply in the coming years. All these mini-devices need energy, mostly from batteries, and there are environmental concerns about this. Swiss EMPA researchers have now developed a biodegradable minicapacitor that could solve that problem.
t consists of carbon, cellulose, glycerin and table salt.
They used a conventional, modified, commercially available 3D printer. The real innovation is therefore not the device, but lies within the recipe for the gelatinous inks this printer can dispense onto a surface. The mixture consists of cellulose nanofibers and cellulose nanocrystallites, plus carbon in the form of carbon black, graphite and activated carbon. To liquefy all this, the researchers use glycerin, water, two different types of alcohol and a pinch of table salt for ionic conductivity.
The result was a kind of minicapacitor that can store electricity for hours and is now able to power a small digital clock. At the end of its life, the battery is easily compostable.
Innovative materials 2021 3)