One-step combustion synthesis of porous CNTs/C/NiMoO4 composites for high-performance asymmetric supercapacitors

A facile and cost-effective one-time solution combustion method is designed for the synthetic of CNTs/C/NiMoO4 and C/NiMoO4 porous composites at 300 °C for 0.5 h in the atmosphere. The characteristics of products are investigated by advanced physical property test and electrochemical analysis. The results reveal that the electrochemical performances of C/NiMoO4 composites are strongly influenced by the molar ratio of oxidizer to fuel and the largest specific capacitance of the optimized sample reaches 859 F g−1 at 1 A g−1. Moreover, the capacitance of CNTs/C/NiMoO4 composites has been further enhanced to 1037 F g−1 at 1 A g−1, in which added acid-treated CNTs into the precursor mixed solution in the combustion process. Furthermore, an asymmetric supercapacitor CNTs/C/NiMoO4||activated carbon (AC) is assembled, which the CNTs/C/NiMoO4 used as cathode and AC used as anode. Its energy density of 32.6 Wh kg−1 at power density of 150.5 W kg−1 and even retains 18.2 Wh kg−1 at 8509 W kg−1. This asymmetric device exhibits a well cycle stability, which the capacitance retain 96.5% after 1500 cycles. The excellent electrochemical behaviors indicate that CNTs/C/NiMoO4 composites have great potential for application in high capacity energy storage devices.