Sodium cholate orchestrated synthesis of silver deposited camphorsulphonic acid doped rodlike polypyrrole architecture for asymmetric supercapacitor applications

An asymmetric supercapacitor (ASC) was developed using camphorsulphonic acid (CSA)-doped polypyrrole (PPY) nanorods as the positive electrode and activated carbon as the negative electrode. The CSA doping and rod-like morphology enhanced the conductivity and electrochemical activity of PPY. Density functional theory (DFT) analysis revealed that CSA significantly lowers the HOMO-LUMO energy gaps of pyrrole oligomers, particularly with increasing chain length, indicating improved electronic properties favorable for charge storage. Electrochemical testing showed that the pristine CSA-doped PPY electrode exhibited a moderate specific capacitance of 180 F g^-1 at 2 mV s^-1, which decreased at higher scan rates. However, after silver nanoparticle deposition on the PPY surface, it displayed a highly reversible and rectangular-type cyclic voltammetry (CV) profile, indicating ideal capacitive behavior, with a specific capacity of 527.28 F g^-1 at a scan rate of 2 mV s^-1. This enhancement was attributed to the strong interaction between silver and the CSA-doped PPY nanorods, which synergistically improved the capacitive performance. The energy density value obtained from the Ragone plot was 12.57 Wh kg^-1. These findings demonstrated the potential of metal-doped conductive polymers for high-performance supercapacitor applications. For real-time evaluation, cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests were performed on the assembled asymmetric supercapacitor (ASC). The ASC employed an Ag-deposited, CSA-doped polypyrrole (PPY) positive electrode and a biowaste-derived activated porous carbon negative electrode. The device delivered a specific capacitance of 208.88 F g^-1 at 2 mA cm^-2, with corresponding gravimetric energy and power densities of 41.78 Wh kg^-1 and 886.89 W kg^-1, respectively.