In recent years, the demand for high-performance flexible and portable electronics with high power/energy density has increased rapidly. Currently, the flexible devices have seized the interest of researchers in energy storage especially, supercapacitors and batteries. Working on the same line, ternary nanostructured polyaniline/Fe2O3-decorated graphene (PGF) composite hydrogel coated on carbon cloth has been prepared as a potential electrode material for flexible supercapacitor. Different compositions of aniline to Fe2O3-decorated graphene have been synthesized by in situ chemical oxidative polymerization. The ternary composite hydrogel on carbon cloth exhibits a high specific capacitance of 1124 F/g at a current density of 0.25 A/g in 1 M H2SO4. The symmetrical supercapacitor has shown high rate capability (∼82.2% at 7.5 A/g) as well as excellent cycling stability. The excellent electrochemical performance of ternary composites hydrogel have been realized because of the well-designed cross-linked hydrogel structure, high surface area, and synergistic effects among all three constituents. This outstanding performance holds great potential for next-generation flexible supercapacitors.

The dc conductivity measured in a wide range of temperatures (room temperature to 533.16 K) for glass samples of compositions 50V2O5·xBi2O3·(50-x) ZnO; x = 0, 5, 10, 15, and 20, is discussed in this paper. The temperature dependent dc conductivity has been analyzed in the framework of various theoretical models, which describe the hopping conduction in disordered semiconducting systems. It has been observed that Mott's model of polaron hopping in transition metals is in good agreement with the experimental data in high as well as intermediate temperature regions. The various polaron hopping parameters have also been deduced. It has been ascertained by these estimated quantities and different approaches that the electrical conduction in present glass system is due to non-adiabatic variable range hopping of small polarons. Moreover, it has been found that Mott's and Greaves’ variable range hopping models are in good agreement with the experimental data in the whole studied temperature range in the present investigation.

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