Fe3O4/MnO2 co-doping phenolic resin porous carbon for high performance supercapacitors

Background: Thus, the excellent electrochemical property of PR-Fe@MnO2 composite made it an encouraging electrode material for practical applications like charge storage and in other pseudocapacitors.Methods: Using phenolic resin (PR) as a carbon source, potassium ferrate (K2FeO4) and manganese acetate (Mn(CH3COO)2 cent 4H2O) as the dopants, a one-step carbonization method was used to prepare a series of Fe3O4 and MnO2 co-doped composites, which are denoted as PR-Fe@MnO2. During high-temperature carbonization (800 degrees C), partially amorphous carbon forms a multi-layer graphene structure, making PR-Fe@MnO2 exhibit a high degree of graphitization. After doping, the transition metal Mn was investigated theoretically by performing density functional theory calculations.Significant Findings: The results confirmed that doping of moderate Mn ions in the PR-Fe lattice improved the interactions between OH- in the electrolyte and Mn metal center, consequently, the electrical conductivity (19%) of the electrode according to the equivalent series resistance (Rs). The Mn composition also increased the specific area for more electroactive sites and reduced the charge transfer resistance (decreased by 27.7%). As a result, PR-Fe@MnO2-1.5 had the highest specific capacitance of 601 F/g at 1.0 A/g and superior cycling stability (capacitance retention of 97.8% after 10,000 cycles). Furthermore, the assembled PRFe@MnO2-1.5//PR-Fe@MnO2-1.5 symmetric supercapacitor provided a specific energy density of 25.7 Wh/ kg at a power density of 384.9 W/kg.(c) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

By moderately doping manganese ions in the PR-Fe lattice, the PR-Fe@MnO2 composite material exhibits excellent electrochemical properties, including high electrical conductivity, increased electroactive sites, reduced charge transfer resistance, high specific capacitance, and superior cycling stability.