Facile flame deposit of CNFs/Fe2O3 coating on 304 stainless steel mesh and their high capacitive performance

Abstract

Carbon nanofibers (CNFs) were directly synthesized on the surface of 304 stainless steel (SS) mesh by a facile one-step ethanol flame synthesis method under a controllable temperature of ∼850 °C, as well as the γ-Fe2O3 particles. The resulted CNFs/Fe2O3/SS mesh electrode is used to assemble a symmetric supercapacitor (SC) with redox active acidic electrolyte, and it exhibits a large area specific capacitance (Ca) up to 2412.6 mF cm−2 at a current density of 3 mA cm−2, and a high energy density of 14.57 mW h cm−3 at a power density of 65.22 mW cm−3. The electrodes also show high cyclic stability, and the specific capacitance retention remains to be 93.55% after 1000 charge-discharge cycles. An asymmetric SC is assembled using the CNFs/Fe2O3/SS as cathode and the WO3/Ti mesh as anode, respectively. It also possesses a high energy density of 9.08 mW h cm−3 at a power density of 70.33 mW cm−3 in a potential window of 0–1.5 V. Their high capacitive performance and good cyclic stability in the acidic electrolyte containing Fe2+/Fe3+ additive could be due to the intrinsic functionalized CNFs produced by the flame deposit method and the reaction balance of the ferric species between the electrode and the electrolyte during the electrochemical process. The facile fabrication method and superior performance of the CNFs/Fe2O3/SS mesh make it promising electrodes for high-performance SCs with specific electrolyte.