Highly Stretchable Supercapacitors Enabled by Interwoven CNTs Partially Embedded in PDMS

Abstract

We present flexible and stretchable supercapacitors composed of interwoven carbon nanotubes (CNTs) embedded in polydimethyl­siloxane (PDMS) substrates. CNTs are grown using atmospheric-pressure chemical vapor deposition (APCVD) on a Si/SiO₂ substrate and then partially embedded into PDMS. This unique process permits a rapid and facile integration of the interwoven CNT–PDMS structure as a flexible and stretchable supercapacitor electrode with a high level of integrity under various strains. The electrochemical properties of the supercapacitors are measured in 30% KOH solution and with a poly­(vinyl alcohol) (PVA)–KOH gel electrolyte (i.e., all-solid-state flexible supercapacitor). The measured capacitance of the supercapacitor is 0.6 mF/cm² in 30% KOH solution and is 0.3 mF/cm² with a PVA–KOH gel electrolyte at a scan rate of 100 mV/s, showing a consistent performance under stretching from 0% to 200% and bending/twisting angles from 0° to 180°. The stretching test is performed for 200 cycles from 0% to 100%, after which its capacitance is attenuated by 25%. The all-solid-state stretchable supercapacitors show a stable galvanostatic performance during and after 10 000 charge/discharge cycles with its capacitance maintained