| Popis: |
The advancements in electrochemical capacitors have noticed a remarkable enhancement in the electrochemical performance for smart electronic device applications, which has led to the invention of novel and low-cost electroactive material. Herein, we synthesized nanostructured Al2O3 and Al2O3-grpahene hybrid, through hydrothermal and post-hydrothermal calcination process. The synthesized materials have been subject to both morphological (FE-SEM, HR-TEM) and structural (XRD and XPS) characterisations. The electrochemical performances of nanostructured Al2O3 and Al2O3-grpahene hybrid were evaluated through computational and experimental analyses. Al2O3-grpahene hybrid shows much improved electrochemical performance, as compared to bare Al2O3. Further, a symmetric supercapacitor device (SSD) was designed using the Al2O3-grpahene hybrid electrodes, which showed 98.56% capacity retention, even after ~ 10,000 charge-discharge cycles. Both, Al2O3 and its graphene hybrid, have been analysed extensively with the help of Density Functional Theory, to provide detailed structural and electronic properties. With the introduction of graphene, the available electronic states, near the Fermi level, are greatly enhanced, imparting a significant increment in the conductivity of the hybrid system. Lower diffusion energy barrier for electrolyte ions and higher quantum capacitance for the hybrid structure compared to pristine Al2O3 justify improvement in charge storage performance for the hybrid structure supporting our experimental findings. |
