Flexible supercapacitors with vertically aligned multiwalled carbon nanotubes (MWCNT) directly synthesized on a metal foil.*

We will present the results of our investigation on all solid-state flexible supercapacitors using MWCNT directly grown on ultrathin Inconel foil. A poly(vinyl alcohol)/phosphoric acid (PVA/H₃PO₄) polymer gel has been used as both the electrolyte and the separator. Since the aligned MWCNT has a higher effective surface area and the direct synthesis on a metal decreases the resistance at the interface, these supercapacitors display improved performance with the highest measured areal specific capacitance of 19.6 mF/cm². Key device parameters, measured and analyzed with standard electrochemical circuit modeling will also be presented. The flexibility of the devices was validated by testing them under different bending angles. These devices can withstand a large amount of such bending cycles, making them more durable and robust energy storage devices.