Tunable all-solid-state wire-shaped high power device based on carbon nanotubes yarn

Energy storage devices integrated into textiles have emerged as a significant strategy for electronic applications. In this context, in the present paper novel flexible devices were developed, in which the control of both the electrode characteristics and the solid-electrolyte properties allows to build all-solid-state wire-shaped supercapacitors that can be integrated and waved. The proposed device was assembled using modified CNT yarns as electrodes and a blend of ionic liquid, Li salt and poly(ethylene glycol) acrylate to fabricate the solid-polymeric electrolyte. Excellent performance in terms of both electrochemical parameters and stability were obtained. These achievements are possible thanks to the coupling of asymmetric CNT yarns, following an optimization of the activation procedure together with the improvement of the polymeric electrolyte. The results show a capacitance as high as 1.8 mF/cm, energy density of 1.3 μWh/cm and a capacitance retention higher than 100% over 1200 cycles.