Experimental and theoretical insights into benzene-1,4-dicarboxylic acid based Co-MOFs: an anodic material for expedient battery-supercapacitor hybrids†

Hybrid supercapacitors, integrating both faradaic and non-faradaic mechanisms, have emerged as promising energy storage devices owing to their high energy density and excellent cycling stability. In the pursuit of sustainable energy storage solutions, the development of advanced materials has garnered significant attention. Herein, we report benzene-1,4-dicarboxylic acid-based cobalt metal-organic frameworks (Co-MOFs) for application in battery supercapacitor hybrid configuration. The Co-MOFs were synthesized via a simple and scalable hydrothermal method, resulting in a mixed nanoflower structure. The electrochemical setup of a bare electrode uncovers its marvelous advantages with a specific capacity of 500.80 C g⁻¹ (3 mV s⁻¹) and 411.13 C g⁻¹ (1.0 A g⁻¹). A predominant diffusive nature of the Co-MOFs (89.11% at 3 mV s⁻¹) was revealed via a simulation approach that back these merits. Furthermore, an asymmetric supercapacitor assembled with the Co-MOFs and activated carbon exhibited high specific capacity (254.45 C g⁻¹), along with outstanding specific energy and power (60.07 W h kg⁻¹ and 850 W kg⁻¹, respectively). Besides, satisfactory rate capability (retains 58.47% of its specific capacity and energy while boosting specific power by 6 times) and a stable cycling life were observed. The simulation of experimental outcomes revealed the hybrid nature of the device with 80.01% diffusive and 76.72% capacitive contribution at 3 and 100 mV s⁻¹, respectively. The findings unveil the Co-MOFs as an excellently tailored and eco-conscious choice for electrode materials in advanced energy storage devices, driving advancements in sustainable energy technologies.