The demand of microelectronic devices postulated high energetic flexible energy storage devices. Flexible solid state supercapacitor is flawless possible candidate to fulfill the requirement of microelectronic devices. This investigation provides practical evidence of the use of flexible solid state supercapacitors based on MnO2 electrodes with polyvinylpyrrolidone (PVP)-LiClO4 gel electrolyte. Initially, different acid mediated growths of MnO2 have been carried. Later, the electrochemical performances of MnO2 electrodes have been carried out. Impressively, the fabricated symmetric flexible solid state supercapacitor (FSS-SC) device demonstrates the highest operating potential window of 1.6V with extended cycling stability. Moreover, the cell exhibits high energy density of 23Wh/kg at power density of 1.9kW/kg. It is interesting to note that the device shows excellent flexibility upon bending at angle of 180° for number of times. These results clearly evidenced those symmetric FSS-SC devices based on MnO2 electrodes are promising energy storage devices for microelectronic applications.