Metal-organic frameworks governed well-aligned conducting polymer/bacterial cellulose membranes with high areal capacitance

Abstract

Conductive bacterial cellulose (BC) membranes are a fascinating class of lightweight and flexible electrodes for electrochemical energy storage. Herein, we demonstrate a simple and efficient method to prepare polypyrrole (PPy)-coated BC electrodes via a template-sacrificing polymerization. Polydopamines serve as the interfacial modifier for the engagement of ZIF-67 polyhedrons along the BC nanofibers. Subsequent metal-organic frameworks-template sacrificing polymerization results in well-ordered PPy alignments along BC nanofibers to afford recovered electrolyte accessible channels. The binder-free electrode exhibits a high areal capacitance of 1.71 F cm−2 (0.4 mA cm−2) and an excellent capacitance retention of 59.8% at 20 mA cm−2. We further use the electrodes to assemble a flexible symmetric supercapacitor, which shows an areal energy density of 89.8 μWh cm−2 at a power density of 0.31 mW cm−2. This work holds great promise in fabricating flexible electrodes for portable energy storage devices.