Purpose. Bifunctional cathode material of manganese (IV) oxide is intended for modern chemical power sources with an air electrode as an electrocatalyst (Zn-air, Li_air system), as well as an active cathode material (MnO2-Zn system, Leclanche element), a reagent for the synthesis of cathode material.
Technical properties. Powder samples of doped manganese (IV) oxide were obtained galvanostatically on a Pt electrode with fluorine-containing electrolytes and additives of ammonium cations, Fe2+, Co2+. FeSO4 and CoSO4 additives were introduced to affect the phase composition and functionality of the electrocrystallization product. Based on the analysis of the optimal combination of high currents of reduction reactions and oxygen evolution, minimal overvoltage of the processes, the composition and concentration, conditions for introducing cationic additives were found.
Application area. The scope of application of the bifunctional cathode material is the production of lithium-air batteries.
Advantages. The concept of electrolytic doping and the results of testing the electrocatalytic activity in the reactions of oxygen reduction evolution allow us to state that among a series of synthesized samples of different compositions of polycation-doped manganese(IV) oxides from electrolytes of different concentrations, this cathode material demonstrated the best electrocatalytic characteristics. Doping with NH4+, Fe2+ and Co2+ cations ensures control of the phase and chemical composition with concentrations of defective states of the surface and volume, including for this system heterovalent Manganese(III, IV) cations in the same crystallographic positions, cation vacancies, OH groups.