The assembled symmetric cell displayed the enriched energy density of 15 Wh Kg -1 along with 96.2% of capacitance retained after 5000 cycles. The electrochemical supercapacitive performance of heteroatom doped CNTs and its composites from the various reports is listed in Table . N (2 at. %); P (0.9 at. %) 358.2 F g -1 @ 0.5 A g - ) is larger than that of NA-CNF-850 (753 m 2 g -1 ), the capacitance of former is lower than the latter due to the content of nitrogen in NA-CNF-900 estimated from XPS analysis to be 3.98 at. % which is lesser compared to NA-CNF-850 at. %). Likewise, the capacitance of NA-CNF-850 is more pronounced compared to NA-CNF-800 owing to the fact that the SBET of former (753 m 2 g -1 ) is relatively larger than the latter (393 m 2 g -1 ). Moreover, the NA-CNFs-850 based symmetric supercapacitor delivered a reasonable energy density of 5.2 Wh Kg -1 along with 94.6% of retention of capacitance after 2000 cycles at 10 A g -1 . From this work, it is evident that both nitrogen content and specific surface area played an equal contribution for the improvement of doped carbon materials towards energy 0.93 g cm -3 , respectively. This might be due to the continuous diffusion of ions from the electrolyte as well as good electrical conductivity. Additionally, increased volumetric capacitance of 359.1 F cm -3 was attained after the decoration of polyaniline over BO-CNF film.