Investigation of charge contribution in Cu2O/Graphene/PEDOT: PSS electrode based 3D-Shaped electrochemical capacitors and development of structural energy storage

Active electrode materials shaped in 3D structures play a crucial role in advancing structural energy storage technologies. We fabricated a 3D-shaped flexible electrochemical capacitor (3D-FEC) utilizing Cu 2 O/Graphene/PEDOT: PSS/Polyurethane foam, enhancing its suitability for structural energy storage. We examined the charge contribution of 2 and 3-electrode configurations during the reaction of these electrodes with NaCl to enhance the energy storage capability. The results showed similar outcomes between both electrode configurations, demonstrating a total charge contribution of 3.4 mC cm −3 at the scan rate of 5 mV s −1 comprising 91.52 % diffusive charge and 8.47 % capacitive charge. We observed a significantly higher diffusive charge contribution at lower scan rates compared to the capacitive charge contribution. The specific capacitance of the 3D-FEC measured from galvanostatic charging discharge analysis is 1.09 F cm −3 (1.17 F g −1 ) at 0.25 mA cm −2 with energy and power densities calculated at 0.25 mA cm −2 was 94.15 μW h cm −3 (0.102 Wh kg −1 ) and 0.985 mW cm −3 (1.06 W kg −1 ) respectively. The influence of external forces in the range of 0.4 N–1.3 N on the top of 3D-FEC leads to negligible variation in performance and it shows its potential application in structural devices. To implement a structural capacitor, several 3D-FECs were affixed to a cloth and combined with a solar cell, forming an energy mat. • 3D-shaped flexible metal oxide-graphene/polymer-based electrochemical capacitor. • The total charge contribution is 3.4 mC cm −3 with 91.52 % from diffusive charge. • The specific capacitance of the device is 1.09 F. cm −3 at 0.25 mA. cm −2 . • The energy (94.15 μW. h. cm −3 ) and power density (0.985 mW. cm −3 ) were calculated. • Structural energy storage was demonstrated using electrochemical capacitors.