Hybrid high performance supercapacitor based on zeolitic imidazolate frameworks-67-derived nano-structure NiCo2S4

Abstract

In this work, NiCo2S4, nickel-cobalt layered double hydroxides (NiCo-LDH) and CoS2 electrodes are successfully prepared by using ZIF-67 as the precursor, the results show that NiCo-LDH and NiCo2S4 are nano-flower-like structures and CoS2 exhibits a nano-cage structure. The electrochemical properties of the hybrid supercapacitor assembled with NiCo2S4 and activated carbon (AC) as electrodes were tested. As the positive electrode of NiCo2S4//AC hybrid supercapacitor, the NiCo2S4 electrode has the largest specific capacity of 2934 mAh g−1 at a current density of 1 A g−1. The NiCo2S4//AC capacitor generates the highest energy density of 38.8 Wh kg−1 when the power density is 993.0 W kg−1 and has a nice cycling performance with a capacity retention rate of 81.2% after 10,000 cycles at 5 A g−1.