Two-for-one strategy: Three-dimensional porous Fe-doped Co3O4 cathode and N-doped carbon anode derived from a single bimetallic metal-organic framework for enhanced hybrid supercapacitor

摘要

"Two-for-one" strategy is an effective method to construct two kinds of materials from a single precursor owing to the simplicity of fabricating procedure and reduction of manufacturing cost. However, such a strategy has seldom been utilized to produce both battery-type and capacitive electrodes of a hybrid supercapacitor (HSC) device. Here, we adopt the ``two-for-one" strategy to fabricate three-dimensional (3D) porous iron-doped (Fe-doped) Co3O4 and nitrogen-doped (N-doped) carbon via a single bimetallic metal-organic framework, FeCo-ZIF-67. Fe-doped amounts and carbonization temperature are used to adjust their individual electrochemical behaviors. The optimal 3D porous Fe-doped Co3O4 and N-doped carbon possess a high capacitance of 767.9 and 277C g(-1) at 1 A g(-1), respectively. Charge storage mechanism of Fe-doped Co3O4 is further investigated via analysis of capacitive and diffusion-controlled contribution. A Fe-doped Co3O4//N-doped carbon HSC device achieves desirable specific energy (37 Wh kg(-1)) and power (750 Wkg(-1)), and satisfied cycling stability (90% retention after 4000 cycles). A light-emitting diode (LED) is successfully light by the HSC device, suggesting its potential application in the field of green energy conversion and storage devices. (C) 2020 Elsevier Inc. All rights reserved.