Cathodic electrophoretic deposition of manganese dioxide films

Cathodic electrophoretic deposition (EPD) method has been developed for the deposition of manganese dioxide films. It was shown that phosphate ester (PE) is an effective charging additive, which provides stabilization of manganese dioxide nanoparticles in suspensions. The influence of PE concentration and deposition voltage on the deposition efficiency has been studied. EPD has been utilized for the fabrication of porous nanostructured films with thickness in the range of 0.5–20μm for application in electrochemical supercapacitors (ES). Cyclic voltammetry and chronopotentiometry data for the films tested in the 0.1M Na2SO4 solutions showed capacitive behavior in the voltage window of 1V. The highest specific capacitance (SC) of ∼377Fg−1 was obtained at a scan rate of 2mVs−1. The SC decreased with increasing film thickness and increasing scan rate in the range of 2–100mVs−1. The deposition mechanism, kinetics of deposition and charge storage properties of the films are discussed.