A crosslinked network polypyrrole coated cobalt doped Fe 2 O 3 @carbon cloth flexible anode material for quasi-solid asymmetric supercapacitors.

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