Boosted charge storage in symmetric supercapacitors using Zn–Co/MgCo2O4 hybrid nanosheets

The pursuit of high-performance electrochemical supercapacitors is driven by the increasing demand for advanced energy storage systems in modern electronics. However, challenges related to the specific capacitance and rate capability of electrode materials continue to limit device performance. In this study, we demonstrate the critical influence of electrode morphology on electrochemical behavior through a comparative investigation of Zn–Co/MgCo2O4 nanosheets and Co/MgCo2O4 nanorods. The unique sheet-like morphology of the Zn–Co/MgCo2O4 facilitates enhanced electrolyte accessibility, faster ion diffusion, and superior charge transfer kinetics, leading to an impressive specific capacitance of 1345 F g−1 at 2 A g−1. In contrast, the conventional rod-like Co/MgCo2O4 exhibits a significantly lower capacitance of 1224 F g−1. The morphology-dependent performance highlights the pivotal role of tailored nanostructures in optimizing electrochemical properties. Furthermore, the Zn–Co/MgCo2O4-based symmetric supercapacitor delivers excellent cycling stability, retaining 83.1 % capacitance after 10,000 cycles. These findings establish the Zn–Co/MgCo2O4 nanosheets as a promising platform for the development of next-generation, high-performance supercapacitors.