Binary nickel–cobalt metal–organic frameworks as electrode for high performance pseudocapacitor

Abstract

Metal–organic frameworks as electrode materials have attracted significant attention due to their high specific surface area and flexible structures. Compared with the metal–organic frameworks derived products, the direct applications of metal–organic frameworks as electrode materials are rather seldom because of their insufficient conductivity. Herein, binary nickel–cobalt based metal–organic frameworks are developed as electrode materials for supercapacitor. The binary metal based metal–organic frameworks behave better electrochemical performance than the sole metal base metal–organic frameworks, and this is majorly due to the synergistic effect between the binary metals. The highest capacitances of 978.9 F g−1 at 1 A g−1 at a nickel/cobalt ratio of 2:4 can be obtained. Meanwhile, the nickel–cobalt metal–organic framework presents excellent stability even after being run for 3000 cycles. The Ni–Co-2-4-MOF//AC asymmetric capacitor shows a high energy density of 14.77 Wh kg−1 and power density of 8477 W kg−1. These results show that Ni–Co-MOFs have a promising applications in supercapacitor electrode.