Microwave-Induced Polyindole on Cobalt MOF-Electrodes for High-Performance Supercapacitors

Abstract

Metal-organic frameworks (MOF) are well-known for their high surface area and porous nature. However, their use in energy storage applications remains limited by their poor electrical conductivity. Here, microwave-induced polyindole modified cobalt MOF composite (CoMP) was constructed to address the poor conductivity of cobalt MOF and improve their applicability in energy storage. The electrochemical performance of the CoMP was investigated in 3 M KOH electrolyte. Deliberate mixing of PIn with Cobalt MOF resulted in effective diffusion of PIn nanospheres into the MOF matrix. With the reticulate porous morphology and large surface area, the CoMP electrode could facilitate easy ion transport at the electrode-electrolyte interface and achieve a maximum specific capacitance as high as 432.6 mF cm −2 at 10 mV s −1 surpassing polyindole (284.5 mF cm −2 ) and cobalt MOF (235.5 mF cm −2 ). Also, the CoMP symmetric supercapacitor delivered high specific energy (8.2 W h cm −2 ) and specific power (622 W cm −2 ) at 2 mA cm −2 with 93% capacitance retention after 5000 GCD cycles.