In situ growth of Co3S4/Ni3S4 on electrospun ZIF-67 nanofibers for high-performance supercapacitor

Recently, MOF derived metal sulfides have drawn much attentions in supercapacitor filed, but its electrochemical performance is limited by their dispersion and stability. Herein, an in situ growth process was designed to fabricate Co3S4/Ni3S4 on electrospun carbon nanofibers modified by ZIF-67, which offered robust structural stability, high redox activities, and enhanced the electron/ion diffusion kinetics. These merits lead to the specific capacitance of 617.78 F g−1 (specific capacity of 278.00 C g−1) at 0.5 A g−1, good rate performance, as well as long cycling durability for CNF@CoNi(1:4)S in three electrode system. Its charge storage mechanism involved in a combined process of surface and diffusion contribution. In addition, an asymmetric supercapacitor (CNF@CoNi(1:4)S//AC) was constructed with the maximum energy density of 40.54 Wh kg−1 (1 A g−1) and the maximum power density of 6788.00 W kg−1. This device also showed an outstanding cyclic performance (its specific capacitance could maintain the initial 115.10 % after 5000 cycles), and provided enough energy for the emission of LED. This work opens an avenue for designing MOF based or metal sulfides based functional materials. A Co3S4/Ni3S4 in situ grown on electrospun ZIF-67 nanofibers was prepared as electrode materials for high-performance supercapacitor. [Display omitted] •A Co3S4/Ni3S4 on ZIF-67-embedded carbon nanofibres was fabricated via an in situ growth method.•The CNF@CoNi(1:4)S sample showed a large specific capacitance, good rate performance and superb cycling stability.•An asymmetric supercapacitor (CNF@CoNi(1:4)S//AC) with a maximum energy density of 40.54 Wh kg−1 has been constructed.•The device displayed excellent cycling performance and provided enough energy for LED emission.