Maity, S.Je, M.Biradar, B.R.Chandewar, P.R.Shee, D.Das, P.P.Mal, S.2026-02-052021Energy and Fuels, 2021, 35, 22, pp. 18824-188328870624https://doi.org/10.1021/acs.energyfuels.1c03300https://idr.nitk.ac.in/handle/123456789/22994Supercapacitors have emerged as one of the most promising candidates for high-performance, safe, clean, and economical routes to store and release of nonfossil energy. Designing hybrid materials by integrating double-layer and pseudocapacitive materials is crucial to achieving high-power and high-energy storage devices simultaneously. Herein, we synthesized a polyoxomolybdate-polypyrrole-graphene oxide nanohybrid via a one-pot reaction. The inclusion of polypyrrole enables a uniform distribution of the polyoxomolybdate clusters; it also confines the restacking of graphene oxide nanosheets. The structural and morphological analysis to unveil the nanohybrid architecture implies excellent interfacial contact, enabling fast redox reaction of polyanions, and a quick transfer of charge to the interfaces. Electrochemical characteristics tested under a two-electrode system exhibit the highest capacitance of 354 F g-1 with significantly high specific energy and power of 49.16 Wh kg-1 and 999.86 W kg-1, respectively. In addition, the cell possesses a high-rate capability and long cycle life by maintaining 96% of its capacitance over 5000 sweeping cycles. The highest specific power of ?10 »000 W kg-1 was computed with Coulombic efficiency of 92.30% at 5 A g-1 current density. Electrochemical impedance spectroscopy additionally reveals enhanced redox charge transfer due to double hybridization. Furthermore, it also demonstrates the impedance and capacitive behavior of supercapacitor cells over a definite frequency regime. ©CapacitanceCharge transferElectrochemical electrodesElectrochemical impedance spectroscopyGrapheneHybrid materialsNanostructured materialsRedox reactionsSupercapacitorDouble layersGraphene oxidesHigh powerHybrids materialNanohybridsNon-fossil energiesPerformancePolyoxomolybdatesSpecific powerSymmetricsPolypyrroles