Highly stretchable hybrid nanomembrane supercapacitors

Abstract

Supercapacitors that are lightweight, mechanically deformable (stretchable, flexible) and electrochemically stable have potential for various applications like portable, wearable, and implantable electronics. Here we demonstrate a stretchable and high-performing hybrid nanomembrane supercapacitor. The hybrid nanomembrane is prepared by vapour phase polymerization (VPP) based nanoscopic PEDOT coating on carbon nanotube sheets (CNS) transferred onto an elastomeric substrate to form a wavy structure. The resulting wavy structured hybrid nanomembrane based supercapacitor exhibits high electrochemical performance and mechanical stretchability, simultaneously. The high specific capacitances and energy density (82 F g⁻¹, 11 mF cm⁻², and 7.28 W h kg⁻¹ at 0% strain) are retained under large mechanical deformation (77 F g⁻¹ and 6.87 W h kg⁻¹ at a biaxial strain of 600%). Moreover, there is only <1% degradation of capacitance ratio after 1000 cycles stretching/releasing and bending/unbending. This high mechanical cyclic stability is shown even during stretching/releasing and bending/unbending measured by dynamic cyclic voltammetry (CV). These results suggest that our supercapacitor is valuable in a wide range of applications that require it to be electrochemically stable under large mechanical deformation, such as strain sensors, wearable electronics and biomedical devices.