°C for 1 h in air and further carbonization at 900 °C for 1 h in nitrogen atmosphere . The RGO-AgNP/N-CNFs assembled symmetric supercapacitor submitted the enhanced energy density and gravimetric capacitance of 26.1 Wh Kg -1 and 188 F g -1 at 0.5 A g -1 which is higher than N-CNFs (110 F g -1 ) and 97.5% retention of capacitance was observed after 5000 cycles at 5 A g -1 . It was suggested that the anchoring of silver nanoparticles over RGO enhance the electrical conductivity and improve the aggregation of silver nanoparticles. The SBET of N-CNFs was amplified to the greater extent from 463.9 m 2 g -1 to1357.3 m 2 g -1 after forming the hybrid with RGO-Ag nanoparticles due to the higher mesoporous content. In another study, the same group fabricated the MnCo2O4@N-CNF hybrid by the electrospinning of stoichiometric quantities of manganese and cobalt salt solutions for 12 h followed by the carbonization at 800 °C for 1 h in the atmosphere with N2 gas and preparations were carried out with different concentrations of manganese precursors . Among the various samples, the hybrid of the MnCo2O4 with N-CNF derived from the 1 mmol of manganese precursor constructed as a symmetric cell and delivered the gravimetric capacitance of 871.5 F g -1 at 0.5