Phys.org June 3, 2021
A team of researchers in Switzerland developed and implemented the concept of a biodegradable electricity storage device. They developed gelatinous inks which consists of cellulose nanofibers and cellulose nanocrystallites, carbon in the form of carbon black, graphite and activated carbon. They used glycerin, water and two different types of alcohol to mix the ingredients and a pinch of table salt for ionic conductivity. They built a functioning supercapacitor from four layers of these ingredients flowing from a 3D printer one after the other: a flexible substrate, a conductive layer, the electrode and finally the electrolyte. The whole thing was folded up like a sandwich, with the electrolyte in the center. The mini capacitor could store electricity for hours and power a small digital clock. It can withstand thousands of charge and discharge cycles and years of storage, even in freezing temperatures, and resistant to pressure and shock. The capacitor disintegrated after it was buried in the soil for two months…read more. TECHNICAL ARTICLE
The biodegradable battery consists of four layers, all flowing out of a 3D printer one after the other…Credit: Gian Vaitl / Empa