Figure shows the GCD profiles of PN and its composites at different current densities between 0.5 F g -1 to 10 F g -1 . The asymmetric and distorted triangular shape in the potential range from 0 V to 1.1 V originates from the pseudocapacitive behavior of the materials. It is especially dominant for PNF and PNZF, thus underscoring their high pseudocapacitive nature compared to PN and PNZ samples (Figure ). Notably, the charge-discharge duration of PNZF surpassed that of the other samples, suggesting the positive contribution of ZnFe2O4 doping to the polymer structure. The synergistic interaction between the ZnFe2O4-dopant and the polymer network resulted in an increase in electrical double-layer capacitance, additionally to the pseudo-capacitance stemming from redox reactions at the electrode interface.