MOF(Ni)/CNT composites with layer structure for high capacitive performance

Abstract

Metal-organic frameworks (MOFs) with high porosity and multivalent metal ion is a kind of prospective material for supercapacitor. However, the poor conductivity and stability degrade the capacitive performance of MOFs. Herein, a corrugated-layered-structure MOF(Ni)/carbon nanotube composite (MOF(Ni)/CNT) was prepared by solvothermal method. The corrugated-layered-structure of MOF(Ni) offers a sufficient electrolyte storage space and a fast ion diffusion channel, and 1D nanotube structure of CNT offers a good electrical conductivity and stability, which makes MOF(Ni)/CNT have an excellent capacitive performance. Compare to MOF(Ni), MOF(Ni)/CNT(w%) have a better electrochemical performance. Especially, MOF(Ni)/CNT(10%) not only has the highest specific capacitance, but also possesses an outstanding rate capacity (88.6% retention at 10 A g−1). Moreover, the asymmetric supercapacitor MOF(Ni)/CNT(10%)//AC can reach 97 F g−1 at 0.5 A g−1 and has 83.2% retention after 5000 cycles. It’s also shows a high energy density of 32.6 Wh kg−1 at a power density of 476.5 W kg−1. This work illustrates that layered MOFs are prospective materials for supercapacitor and provides a facile and effective way to boost the capacitive performance.