Polyaniline Graphene Oxide (PANI-GO) composites have been synthesized through simple and scalable oxidative in-situ emulsion polymerization route. Reaction parameters were optimized by varying the concentrations of monomer, acid, oxidant and graphene oxide to obtain composites with optimum performance. Different structural and morphological features of the composited were characterized through Ultra Violet–Visible (UV-Visible) and Fourier-Transform Infra-Red (FTIR) spectroscopy, X-Ray Diffraction (XRD) and Thermogravimetric Analysis (TGA) analysis. TGA showed very good thermal stability. To further access the thermal properties and calculate energy of activation for degradation of samples Horowitz and Metzger methods were used. Highest thermal stability and energy of activation for degradation was depicted by PANI-GO-6. High thermal stability enables PANI-GO composite to be utilized at high temperature applications. Conductivity measurements of the synthesized materials demonstrated that small amount of GO increases the conductivity of composites when compared with pristine PANI. This might be due to synergistic effect of PANI and GO in resulting composites. These results are also consistent with electrochemical analysis. Electrochemical and supercapacitor properties were analyzed through Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD) analysis and Electrochemical Impedance Spectroscopy (EIS) in three electrode setup using aqueous H2SO4. The CV and GCD curves suggested the material to be supercapacitive with low internal resistance. The nearly vertical arm of the AC impedance in the low frequency region depicted excellent capacitive behavior, representative of fast ion diffusion and adsorption in/on the electrode material. Nyquist plot showed very low solution resistance, Rs, charge transfer, Rct, and equivalent series resistance, ESR, for PANIGO-6. The low Rct is beneficial for fast charge transfer and allows for more charge storage. Form Bode plots the phase angle value is 86.340 which is closer to that of an ideal capacitor. The lower time constant value (0.630 s) provides evidence for faster ion diffusion and transport inside the whole inner structures. Symmetric, asymmetric and solid state devices were fabricated by using selected PANI-GO samples as electrode material. In symmetric device CV, was carried out at a scan rate of 10 mV/s at potential window form 0 to 0.6, 0.7, 0.8 and 0.9 V. Then at a scan rate of 10, 30, 50, 70, 100, 200, 300, 400 and 500 mV/s at potential range from 0-0.9 V. CVs were almost rectangular in shape and retained its shape even at high scan rates thus showed electrochemical double layer capacitance (EDLC) and high rate capability. GCD analysis showed capacitance value of 264 F/g at 1 A/g and retained its value 84.09 % at high current density (10 A/g) with excellent rate performance. EIS analysis showed lower Rct, Rs, ESR and t0 which are consistent with other results. The material was active upto 2000 charge discharge cycles. To further access its performance asymmetric device was fabricated. It showed excellent capacitive properties with extended potential window up to 1.2 V. GCD analysis showed excellent stability and columbic efficacy. To achieve cost affective energy storage appliances, symmetric devices using copper and steel current collectors were also fabricated. Their response as was quite good and is a step towards reducing the cost of energy storage devices. Further to overcome the leakage problem associated with liquid electrolytes solid state devices were also fabricated using poly(vinyl alcohol-H2SO4) (PVA-H2SO4) gel electrolyte. Thus, the synthesized composites can be used for high temperature applications due to its excellent stability and can be utilized in aqueous symmetric, asymmetric, symmetric solid state devices using different current collectors.