Flexible and stretchable polyaniline supercapacitor with a high rate capability

Flexible electronics are currently highly favored because of their promising applications in flexible displays, artificial electronic skin, wearable devices etc. Exploiting flexible energy storage systems, which are supercapacitors, that have a decent electrochemical performance as well as flexibility and stretchability is essential to promote the development of flexible electronic products. In this work, a flexible and stretchable polyaniline (PANI) supercapacitor based on a conductive stainless steel mesh was developed via a simple electrodeposition route with an elastic gel polyvinyl alcohol polymer (PVA)/phosphoric acid (H₃PO₄) electrolyte, which exhibits a considerable rate capability and mechanical properties. The as-prepared capacitor delivers a specific capacitance of 282 F g⁻¹ under a specific current of 2.5 A g⁻¹. Meanwhile, the PANI capacitor exhibits perfect pseudocapacitance behavior at low scan rates (up to 50 mV s⁻¹) and great capacitive characteristics at high scan rates up to 5000 mV s⁻¹. More impressively, this supercapacitor displays excellent tolerance against mechanical deformation, including bending, folding and stretching, even to 20%, with a well-maintained capacitance. This stretchable PANI supercapacitor with a high rate capability provides a facile and cost-effective route for the design of flexible energy storage devices.