Inorganic–Organic Hybrids of Tungsten Oxide as the High Performance Intercalation Supercapacitor Electrodes

In this research, the layered inorganic–organic hybrids materials based on tungsten oxide were synthesized using three amino-hydroxy ligands; 2-(2-aminoethoxy) ethanol (AEE), 2-(2-aminoethylamino) ethanol, and diethylenetriamine, by direct intercalation of these guest ligands. Then, the synthesized hybrids were applied as the novel supercapacitor electrode materials. Various analytical techniques were utilized to investigate the interaction between the inorganic and organic components and to understand how the intercalation of organic guests effects on the electrocapacitive performance of the electrodes. The evaluation of electrodes properties shows the outstanding performance of the [WO3·AEE] hybrid electrode that is annealed at 300 °C, the hybrid with more oxygen donor ligands versus the other ligands that have more amino groups. This hybrid has the highest specific capacitance of 207.27 F/g at the current density of 2 A/g with 100% capacitance retention. Also, this hybrid electrode exhibits a good power density of 1127 Wh kg−1 at the energy density of 1.25 kW kg−1. These results exhibit the outstanding electrocapacitive performance of hybrids revealing from the synergetic effects of organic and inorganic parts in the hybrids that made them more active than pure WO3 electrode. The intercalations of organic guests increase the oxide interlayer space that can accelerate the ion diffusion. Also, the electron donations of organic guests to the tungsten inorganic center can surprisingly increase the kinetics of electron transfer and consequently improve the performance of the electrode.