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.

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With the rapid development of portable, lightweight, and flexible electronics, the requirement for advanced energy storage systems has arisen that need to be flexible and cost‐effective with higher power/energy densities. In this context, a two‐step approach has been adopted to develop a binder‐free and flexible supercapacitor electrode on carbon cloth based on hierarchical three dimensional (3D) conducting polymer hydrogels. Firstly, nitrogen‐doped graphene (NGN) was synthesized using urea as a reducing as well as a doping agent. Subsequently, polyaniline (PAni) hydrogel has been grown on NGN nanosheets via insitu oxidative polymerization in the vicinity of carbon cloth and further utilized as an electrode for electrochemical measurements. Here, phytic acid was used as a gelatinizer and as a dopant resulting in the formation of a cross‐linked hydrogel structure. The direct deposition of PAni/NGN nanocomposite on carbon cloth strengthens the juncture involving the carbon cloth and electrode material, resulting in enhanced electron transmission. The 3D hydrogel architecture ascertains robust contact between electrolyte and electrode for an efficient charge storage system. For a two‐electrode symmetric arrangement, at 1 A/g, PAni/NGN nanocomposite hydrogel displayed a maximum specific capacitance of 808.7 F/g due to the pseudocapacitive reaction on/near the accessible surface area, as well as an outstanding rate capability and cyclic performance due to electric double layer capacitance (EDLC). The supercapacitor cell delivered maximum specific power and specific energy value of 0.44 kW/kg and 13.63 Wh/kg, respectively. Thus, the composite hydrogel has the benefit of being able to be utilized directly as binder‐free supercapacitor electrodes, leading to viable choice for high‐performance and cost‐effective energy storage devices.

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