Double-Layer Carbon Encapsulated with Iron-Doped Cobalt Hydroxide on Cu2o for High-Performance Supercapacitor Anode

Abstract

In this paper, we propose an intriguing method to reasonably design porous carbon derived from ZIF-67 (cobalt-based metal-organic framework-67) on copper foam, and further optimize the proportion of iron ions in cobalt hydroxide based on Cu2O/nanoporous carbon (Cu2O/NPC). Finally, we electrodeposited PPy nanowires on it to obtain a kind of negative electrode material. The resulting anode material Cu2O/NPC@CoFe0.15(OH)x/PPy-20 (CNCF0.15P2) with an excellent electrochemical performance of 11.8 F cm-2, and 2500 cycles with almost no decay. Favorable morphology for charge transfer, lower charge transfer resistance, and small diffusion resistance are reasons for the excellent cycle performance. In addition, an asymmetric device based on the CNCF0.15P2 electrode and cobalt-nickel bimetallic hydroxide electrode can reflect an ideal energy density up to 0.44 mWh cm-2 at 2.4 mW cm-2 with significant cycling performance. This study shows that the CNCF0.15P2 negative electrode is an attractive electrode for constructing energy storage devices, and it provides a certain reference for the development of copper-based supercapacitors.

Keywords: Supercapacitors, negative electrode, ZIF-67-derived porous carbon, high area capacitance