A g -1 in 0.5 M Na2SO4 as the electrolyte and displayed in Fig. . They claimed that the pronounced performance towards charge storage is due to the SBET of SmMO-NPRGO was 438 m 2 g -1 that is relatively higher than SmMO (100 m 2 g -1 ) and SmMO-RGO (241 m 2 g -1 ). This graphene core-shell structure was prepared by subjecting the polymerisation of Al-Co9S8@rGO composite with necessary amount of pyrrole along with required reagents for polymerisation accompanied by the calcination under Ar atmosphere at 600 and 900 °C for 2 h. The specific capacity of Al-Co9S8@NG-600, Al-Co9S8@NG-900 and Al-Co9S8 derived from the CD curve at 1 A g -1 were found to be 736, 360 and 228 C g -1 at 1 A g -1 in 2 M KOH solution. 92% capacitance retained from its original value obtained for Al-Co9S8@NG-600 after 10000 cycles at 20 A g -1 . The substantial increment towards electrochemical performance was interpreted as a result of the fact that the SBET of Al-Co9S8@NG-600 was found to be 66 m 2 g -1 which is 5 times greater than Al-Co9S8 (12 m 2 g -1 ) suggesting that the core-shell structure furnishes a greater number of accessible active sites which is solely suitable for supercapacitor application.