Influence of doped anions on PEDOT/Ni-Mn-Co-O for supercapacitor electrode material

The excellent hole-conducting poly(3,4-ethylenedioxythiophene) (PEDOT) is able to improve the electrochemical properties of nickel cobalt manganese oxides (NMCOs). In this work, we applied solvothermal-coprecipitation coupled with oxidative polymerization to synthesize a hybrid of PEDOT /Ni-Mn-Co-O and investigated the influence of different doping anions on its supercapacitor performance. The anions analyzed in this work were 4-methylbenzenesulfonate, camphorsulfonate, dodecyl benzene sulfonate, sulfamate, and sulfosalicylate. The electrochemistry, physical properties, specific capacitance, and specific discharge of the hybrid samples were determined for single electrodes in 6 M KOH. With PEDOT:SCS/NMCO high doping levels per monomer were achieved, and the hybrid exhibited overwhelming electrochemical properties with a specific capacitance of 540 F g⁻¹ at a current density of 1 A g⁻¹, and a good capacitance retention of 98.3% after 5000 cycles at a high current density of 5 A g⁻¹. Furthermore, the influence of the structure, molecular chain length, and the degree of conjugation of the doping anions on the doping level and electrochemical performance of the prepared materials were investigated. These results provide an important theoretical basis for the application of PEDOT based compounds in energy storage.