Morphology-controllable bimetallic MOFs/textile composite electrodes with high areal capacitance for flexible electronic devices

Abstract

A new strategy has been designed for enhancing the electrochemical performances of supercapacitor electrodes. In this work, flexible hetero-structure conductive cotton equipped with lamellar structure nickel/cobalt-based MOFs (NiCo-MOFs) is prepared through a self-sacrificial template method. The in situ conversion measure effectively strengthens the binding forces between the active materials and the current collector, which decreases the charge transfer resistance at the electrode–electrolyte interfaces. Morphological modulation of the NiCo-MOFs is carried out to construct fast transport channels for ions and charges during the charging–discharging process. The optimized NiC/NiCoMOF21 is composed of uniformly dispersed nanosheets with large gaps, which can provide more free space and active sites for electrode reactions. The energy density of the asymmetric supercapacitor (carbon cloth as the negative electrode) reaches 0.38 mW h cm⁻² at 1.6 mW cm⁻² (16.7% loss of the initial capacity after 2000 cycles), which overcomes the low energy storage performance of the existing textile-based electrodes.