Аннотация:Anodic behavior of Mn5Si3 electrode in sulfuric acid and alkaline solutions was studied by polariza-tion and impedance measurements.It was concluded that the surface of manganese silicide in a sulfate electrolyte is coated with an oxide film similar in composition to SiO2, and in an alkaline electrolyte it is enriched with manganese and its oxidation products. For sulfate electrolyte, the thickness and resis-tivity of the oxide film were calculated depending on the potential and composition of the solution. For an alkaline electrolyte, the change in the thickness of the passivating film was calculated depending on the potential and concentration of NaOH, and the kinetic parameters of the oxygen evolution reaction were determined.