基于氧化还原活性NiO和ZnO掺杂的二元PPy/PANI聚合物基体超级电容器的电化学研究

The increasing need for efficient energy storage devices is continually motivating the researchers to design high-performance supercapacitors. In the present research work, we report a comprehensive electrochemical comparison between two distinct polypyrrole/polyaniline (PPy/PANI)-based ternary electrodes, namely NiO/PPy-PANI and ZnO/PPy-PANI. The ternary nanocomposites were effectively prepared by single-step chemical oxidative polymerization route. XRD, FTIR, FESEM, and XPS analyses were used to authenticate the embedment of NiO and ZnO within the PPy/PANI polymeric matrix. Further, the prepared ternary NiO/PPy-PANI and ZnO/PPy-PANI nanomaterials were developed as electrodes to assess their electrochemical properties using a three-electrode cell assembly in 1 M KOH electrolyte medium. CV results show that the fabricated NiO/PPy-PANI electrode delivered a specific capacitance of 430 F/g at 5 mV/s, which is notably higher compared to the ZnO/PPy-PANI (245 F/g) electrode. The improved energy storage capability of the NiO/PPy-PANI electrode is further confirmed by its extended charge–discharge curve and minimum IR drop at 5 A/g. In addition, the NiO/PPy-PANI electrode exhibited a lower ESR value of 0.36 Ω compared to the ZnO/PPy-PANI (1.72 Ω) electrode and maintained 84% of capacitance retention over 2500 cycles. These results suggest that the NiO-incorporated PPy-PANI-based electrode exhibited increased electrochemical activity. In addition, the symmetric supercapacitor device fabricated using NiO/PPy-PANI electrodes exhibited a specific capacitance of 91 F/g and maximum energy density of 15 Wh/kg for the power density of 1325 W/kg at a current density of 5 A/g. The low ESR value of 2.12 Ω and the capacitance retention of 72% after 2500 repetitive charge/discharge cycles demonstrate the device suitability for sustainable and efficient energy storage.