The optimised BCN where the content of boric acid as well urea and glucose are in the weight ratio 1:4 achieved the increased capacitance of 465 F g -1 at 0.1 A g -1 in 1 M H2SO4 along with amplified stability of 98.5 % retention in capacitance after 10000 cycles. The remarkable supercapacitance performance is attributed to the existence of huge defects over the BCN nanosheets that accelerated the diffusion rate of ions towards the electrode surface for imparting the pseudocapacitance and the increased SBET of 600.9 m 2 g -1 . The same material was followed by freeze-drying and the subsequent annealing at 900 °C about 5 h in the atmosphere of N2 gas. The hybrid of BCN with PANI delivered the gravimetric capacitance of 672 F g -1 at 1 A g -1 in 1 M H2SO4 which is higher than BCN and PANI along with 89.6% of retention of capacitance after 10000 cycles. It is essential to emphasize that the working window of PANI is restricted to 1 V even with Et4NBF4 electrolyte and the voltage window of the hybrid of BCN with PANI can be enhanced by three-fold that of PANI. Also, characterization studies such as Raman and XRD validated the severe π-π stacking from BCN to PANI. It was proposed that the influence of unbound π-electrons linked the charge transfer each other that allowed the electron cloud restricted to the only one component that enhance the conjugation and leading to generate the stronger force over the electrolyte ions during charge-discharge and hence the operating window of the hybrid of BCN with PANI enhanced to 3 V as clearly observed from