Diffusion kinetics of <scp>CuCo<sub>2</sub>O<sub>4</sub></scp> nanorods for next‐generation solid state sodium‐ion <scp>hybrid supercapacitor</scp>
Deependra Jhankal, Mohammed Saquib Khan, Bhanu Yadav, Preeti Shakya, Nikita Bhardwaj, K. K. Jhankal, K. Sachdev
Abstract
Abstract In the current study, we report a straightforward and affordable sol‐gel preparation approach for the fabrication of spinel CuCo 2 O 4 nanorods for sodium ion‐based hybrid supercapacitor. The morphological and structural analysis shows that appropriate purity nanorods of CuCo 2 O 4 are formed with good stoichiometry. The electrochemical study of CuCo 2 O 4 nanorods reveals that the electrode has highest specific capacitance of 367 F g −1 at 1 A g −1 in 1 M Na 2 SO 4 electrolyte. Evaluation of the diffusion kinetics of sodium ions through detailed electrochemical evaluations of cyclic voltammogram (CV) showing the charge storage kinetics of CuCo 2 O 4 is primarily performed through the diffusive limited mechanisms, suggesting the battery‐like behavior of CuCo 2 O 4 electrode. Hybrid supercapacitor (HSC) device is fabricated by utilizing CuCo 2 O 4 for positive and reduced graphene oxide (rGO) for negative electrodes material. The polymer gel electrolyte is used in the form of hydrogel membrane made of PVA and Na 2 SO 4 , and the HSC device (rGO || CuCo 2 O 4 ) exhibits energy density of 9.18 Wh kg −1 . Therefore, sodium‐ion hybrid supercapacitor electrode materials for this investigation are established using a comprehensive electrochemical kinetics.