Electrochemical Co-deposition Of Polyaniline And Manganese Oxide

Polyaniline(PANI)is one of the most promising pseudocapacitive materials because of its good electrical conductivity and highly reversible electrochemical activity.However,PANI tends to generate the secondary growth to form a compact deposition layer in the process of polymerization,which hinders its application for energy storage.Manganese oxide(MnOx)is an important transition metal oxide,having many advantages including earth abundance and high electrochemical activities.It also has great application potential in supercapacitors.However,the electrochemical performances of MnOx are usually restricted by its poor electrical conductivity.In-situ combination of PANI with MnOx through electrochemical co-depositions is an effective way to solve the above problems.In this work,electrochemical co-depositions of PANI and MnOx were conducted on the pretreatment partial exfoliated graphite foil(EGF)in solutions containing MnSO4 and aniline by cyclic voltammetry(CV),to afford PANI/MnOx composite electrodes.Influences of CV scanning cycles as well as concentrations of MnSO4 and aniline in electrolyte on the electrochemical co-depositions of PANI and MnOx were investigated.Scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDX),fourier transform infrared spectroscopy(FT-IR)and X-ray diffraction(XRD)were used to characterize the PANI/MnOx composite film.CV and galvanostatic charge-discharge tests were conducted to investigate the electrochemical properties of the PANI/MnOx composite.It was suggested by the XRD results that the MnOx in the composite is amorphous.The EDS spectrum of the composite revealed the presence of elements of Mn from MnOx and N from PANI.This is in agreement with the FT-IR spectrum,where characteristic vibrations relevant to MnOx and PANI were detected.The SEM result showed that the PANI/MnOx composite,PM-100-10-10,prepared by 100 times CV scans in a solution containing 0.10 M MnSO4 and 0.10 M aniline,demonstrated a one-dimensional nanofiber structure.This composite displayed an excellent electrochemical performance with an areal capacitance of 1435.81 mF cm-2 at 1 mA cm-2.When the current density increased to 15 mA cm-2,its areal capacitance is still as high as 764.17 mF cm-2.