ZIF‐67 Integrated Nb ₂ CT _x MXene Composites as Efficient Electrode Material for Asymmetric Supercapacitor Application

ABSTRACT

The development of hybrid composites combining conductive two‐dimensional materials with porous metal‐organic frameworks has emerged as an efficient strategy to enhance the electrochemical performance of supercapacitors. In this work, ZIF‐67@Nb ₂ CT _x MXene composites are investigated as supercapacitor electrode materials. The composites are prepared with different Nb ₂ CT _x wt% in ZIF‐67, and the composite with 2 wt.% Nb ₂ CT _x in ZIF‐67 shows the best electrochemical performance in 2 

KOH, with a specific capacitance of 541 F/g at 1 A/g in the three‐electrode system. The asymmetric device AC//KOH//ZX67‐2 exhibits a specific capacitance of 173.9 F/g at 0.5 A/g, a specific energy of 63.77 Wh/kg at a specific power of 800 W/kg, with an operating potential window of 1.6 V. Intercalating ZIF‐67 into Nb ₂ CT _x sheets enhanced the conductivity and electrochemical performance of the nanocomposites. The charge‐transfer resistance of the best‐performing material, ZX67‐2, is 0.95 Ω. Furthermore, A binder‐free coin cell was fabricated, exhibiting a specific energy of 24.28 Wh/kg at a specific power of 2 kW/kg and 78% capacitance retention over 10,000 cycles at 1 A/g and LEDs of different colours were lit.