One-Pot Synthesis of Polyoxometalate Decorated Polyindole for Energy Storage Supercapacitors

Abstract

The demand for energy storage supercapacitor devices has increased interest in completing all innovative technologies and renewable energy requirements. Here, we report a simple method of two polyoxomolybdate (H 4 [PVMo 11 O 40 ] and H 5 [PV 2 Mo 10 O 40 ]) doped polyindole (PIn) composites for electrochemical supercapacitors. The interactions between polyoxomolybdates and PIn were measured by Fourier transform infrared spectroscopy (FTIR), and powder XRD, and stability was measured by thermogravimetry. The field emission scanning microscopy (FESEM) was employed to investigate the morphology of the materials. The electrochemical measurements show that the PIn/PV 2 Mo 10 electrode exhibits a higher capacitance of 198.09 F/g with an energy density of 10.19 Wh/kg and a power density of 198.54 W/kg at 0.2 A/g current density than the PIn/PVMo 11 electrode. Both electrodes show a pseudocapacitance behavior due to the doping of redox-active polyoxomolybdates on the PIn surface and enhance the electrochemical properties. The electrodes’ capacitive nature was measured by electrochemical impedance spectroscopy (EIS), which shows that the PIn/PVMo 11 electrode has a resistive nature within the electrode–electrode interface. Moreover, the PIn/PV 2 Mo 10 electrode offers remarkable cycle stability, retaining ∼84% of its capacitance after 10,000 cycles (∼83% for the PIn/PVMo 11 electrode). The higher specific capacitance, faster charge/discharge rates, and higher cycle stability make them promising electrodes in supercapacitors.

A Review of Supercapacitors: Materials Design, Modification, and Applications

“…The composite exhibited a higher specific capacitance of (365 F/g at 1 A g −1 ) relative to the single components and employed as electrode material in supercapacitors. Anjana et al [226] prepared the composite polyoxomolybdate/polyindole (PIn/PV 2 Mo 10 ) via the in situ oxidative polymerization process. The composite was found to have higher specific capacitance, faster charge/discharge rates, and greater cycle stability and was used as a promising electrode material in a supercapacitor.…”

Recent Advances in Graphene and Conductive Polymer Composites for Supercapacitor Electrodes: A Review

“…In recent years, many CPs have been explored and used to manufacture CP/graphene composites in combination with graphene. The application of CP/graphene composites, such as SCs [42,43], solar cells [44], fuel cells [45], sensing platforms [46], etc., has also been investigated, and the application in SCs has aroused great interest among researchers due to the excellent electrochemical property of CP/graphene composites. These CP/graphene SC electrodes, which are supposed to combine the advantages of both CPs and graphene, show significant improvements on their capacitance performance and cyclic stability.…”

Capped Keggin Type Polyoxometalate-Based Inorganic–Organic Hybrids Involving In Situ Ligand Transformation as Supercapacitors and Efficient Electrochemical Sensors for Detecting Cr(VI)

“…To overcome these disadvantages, one of the strategies is to anchor the POMs to the host material, including activated carbon, 3 graphene, 8 polyindole, 9 carbon nanotube, 10 poly-pyrrole, 11 etc., enhancing the stability and conductivity of the structures and increasing the energy density of the electrode materials. Another potential approach is the combination of POM and a metal−organic framework, because such obtained complexes based on POMs isolated under hydrothermal conditions as electrode materials exhibit poor solubility in most solvents and satisfying stability during the charge/ discharge process and their defined structures are beneficial for the investigation of the effect between the structure and property.…”