A crosslinked network polypyrrole coated cobalt doped Fe2O3@carbon cloth flexible anode material for quasi-solid asymmetric supercapacitors

Abstract

Iron(III) oxide (Fe₂O₃) exhibits a substantial theoretical specific capacitance and a broad operational voltage window, making it a prospective anode material. The crystal structure of Fe₂O₃ was altered through cobalt doping, and its electronic conductivity was improved by supporting it with carbon cloth (Co-Fe₂O₃@CC). Subsequently, a crosslinked network of polypyrrole (PPy) was synthesized onto Co-Fe₂O₃@CC via an ice-water bath, resulting in the formation of PPy/Co-Fe₂O₃@CC. This PPy nano-crosslinked network not only established three-dimensional electron transport pathways on the Fe₂O₃ surface but also amplified the composite material's specific surface area to 45.229 m² g⁻¹, thereby promoting its electrochemical performance. At a current density of 2 mA cm⁻², PPy/Co-Fe₂O₃@CC displayed an area specific capacitance of 704 mF cm⁻², a value 2.2 times higher than that of Co-Fe₂O₃@CC. The assembled PPy/Co-Fe₂O₃@CC//Ni-MnO₂@CC asymmetric supercapacitor demonstrated an energy density of 1.41 mW h cm⁻³ at a power density of 54 mW cm⁻³, making the synthesized electrode material a promising candidate for flexible supercapacitors.