Herein, we report an environment friendly methodology for the synthesis of carbon aerogel (CA) using bio-mass (mustard oil) as precursor. The synthesis process is highly reproducible and economical yet devoid of any sophisticated procedure and hazardous organic/inorganic chemicals. Exfoliated graphitic planes of carbon beads with enhanced inter-planer spacing are observed in synthesized CA with low bulk density (0.144 g cm(-3)) and high specific surface area (1032 m(2) g(-1)). The CA comprises of meso/microporosity with open pore microstructure. Symmetric supercapacitor cell (CA vertical bar vertical bar CA) is fabricated to test the capacitive performance of CA in H2SO4-polyvinyl alcohol (H2SO4-PVA) gel as electrolyte. The CA vertical bar vertical bar CA cell exhibits nearly symmetrical voltammograms up to working potential window of 2 V and impedance response demonstrates phase angle 80 indicating highly capacitive behavior. Polyaniline (PANI) spikes are further synthesized over CA using chemical oxidative polymerization route to introduce pseudocapacitive characteristics in addition to double layer capacitance. Solid-state symmetric (CA-PANI vertical bar vertical bar CA-PANI) and asymmetric (CA vertical bar vertical bar CA-PANI) supercapacitor cells are fabricated to examine the electrochemical performance. Fabricated CA vertical bar vertical bar CA-PANI supercapacitor cell exhibits remarkable high power density (7.9 kW kg(-1)) and high energy density (55.6 Wh kg(-1)). The CA vertical bar vertical bar CA-PANI cell is capable to power a light-emitting diode (LED) bulb effectively for 3.5 min by assembling two supercapacitors (1 x 1 cm(2)). (C) 2017 Elsevier Ltd. All rights reserved.