With their ability to charge and release large amounts of electric power in a very short time, supercapacitors are used in regenerative braking, as power buffers in wind turbines, and in consumer electronics such as laptop computers and digital cameras.
To make a supercapacitor fit for wearables and paper electronics, the researchers developed a polyelectrolyte composed of a polyacrylamide hydrogel reinforced with vinyl-functionalised silica nanoparticles (VSNPs).
This material is said to be made stretchable by the cross-links in the vinyl-silica nanoparticle and conductive because the polyelectrolyte, which swells with water, both holds and transfers ions.
"VSNPs cross-linkers serve as stress buffers to dissipate energy and homogenise the PAM network. These synergistic effects are responsible for the intrinsic super-stretchability and compressibility of our supercapacitor," said associate professor Chang Zhi, pictured.
To assemble a working supercapacitor with this polyelectrolyte, two identical carbon nanotube composite paper electrodes were directly paved on each side of the pre-stretched polyelectrolyte film.
According to the researchers, a wavy, accordion-like structure developed upon release, showing surprising electrochemical behaviour. The electrochemical performance was said to be enhanced with the increase of strain.
