Architecting cobalt molybdate nanostructures via urea tuning: promising battery-type electrodes for high energy density hybrid supercapacitors

초록

Engineering the architecture of nanomaterials with favorable structural and morphological properties is essential for enhancing the electrochemical performance of advanced energy storage devices. In this study, we developed cobalt molybdate (CoMoO4: CM) nanostructures using a simple hydrothermal method that allows precise morphological tuning. By adjusting the surfactant concentration, we transformed CM from rod-like structures to flake-like, and finally to marigold flower-like structures, which we designated as R-CM, F-CM, and MF-CM, respectively. The 3D hierarchical marigold flower-like nanostructures (MF-CM), composed of 2D flake-like elements, provide a high surface area, numerous electroactive sites, effective ion transport pathways, and an extensive electrode-electrolyte interface. The MF-CM electrode showcased an impressive specific capacity of 1064.6 C g- 1 as a battery-type supercapacitor electrode at a current density of 1 A g- 1, surpassing the R-CM and F-CM electrodes, which registered 511.2 C g- 1 and 748.3 C g- 1, respectively. In addition, the MF-CM//AC HSC device achieved a high energy density of 77.9 Wh kg- 1 at 928.2 W kg- 1 and maintained a strong cycling stability of 85.3% at 5 A g- 1 after 10,000 GCD cycles. This study thus highlights the significant potential of morphology tuning in improving the electrochemical performance of battery-type electrodes for supercapacitor applications.

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