Hierarchical sheet-like Ni–Co layered double hydroxide derived from a MOF template for high-performance supercapacitors

Abstract

Metal-organic frameworks (MOFs) are particularly attractive as a promising alternative in the field of energy storage and conversion. However, it exhibits limited electrochemical performance owing to their intrinsic instability and poor conductivity. In order to obtain more conductive electrode materials suitable for supercapacitor, a simple and effective precursor conversion method is explored to synthesize Ni–Co layered double hydroxides (LDH) composite using Co-Ni metal–organic framework (Co-Ni-MOF) as sacrificed template and precursor. The MOF-derived amorphous LDH composite is found to have a sheet-like structure, which can provide favorable paths for electrolyte penetration and also enhance the contact area of active material and electrolyte. The electrochemical data demonstrate that LDH composite delivers a specific capacitance of 1265Fg−1 at the current density of 1Ag−1 superior to Co-Ni-MOF (570Fg−1 at 1Ag−1), good cyclic stability and also a relatively low resistance. These results suggest the flexible LDH synthesized by a facile method could potentially be applied for supercapacitors.