MOF derived CoFe-layered double hydroxide nanosheets for a high-performance hybrid supercapacitor

Abstract

Rational design of surface of electrode material to avoid stacking is the key to develop new electrode materials with good electrochemical properties. In this paper, a ZIF-67 template method to synthesize CoFe-LDH nanosheets array with abundant active sites is developed in room temperature. The optimized CoFe-LDH electrode has a maximum specific capacitance of 1824 F g⁻¹ at 1 A g⁻¹ and excellent rate performance (82% at 5 A g⁻¹), maintaining 91% of initial capacitance after 5000 cycles. The excellent properties come from the fact that MOF-derived CoFe-LDH inherits the layered structure of MOF, promotes the transfer of electrons and ions, enriches the active site, and coordinates the surface to avoid agglomeration. In addition, the assembled asymmetric SCs device assembled with activated carbon (AC) as the cathode and CoFe-LDH as the anode achieves a superior energy density of 31.56 Wh kg⁻¹ at 750.1 W kg⁻¹ with significant cycle stability (remained 84% of the initial capacitance after 10,000 cycles). Impressively, the design concepts of complex structures from metal–organic framework (MOF) derivatives shows great potential for use in energy storage systems.