ИСТИНА

Nowadays the need for new highly efficient energy sources is growing, among them the leading role is played by electrochemical devices. Particular attention is paid to the hydrogen-bromate flow battery where the generation of current is associated with the reaction of hydrogen oxidation and reduction of the bromate anion. [1,2]. Such a battery exhibits high theoretical values of current and energy densities [1]; however there is a number of issues to be solved before its practical implementation. One of them is a crossover, i.e. the penetration of cathodic reaction components (bromate, bromide and bromine) into the anode compartment which causes a decrease in battery efficiency due to the direct transfer of charges from the oxidizer to the reducing agent and adsorption of bromine on the platinum anode of the battery. To study the crossover we proposed an original method based on measuring the electrochemical characteristics of a smooth platinum electrode whose surface is separated from the electrolyte by the Nafion membrane. In a series of experiments the composition of the system (aqueous solutions of sulfuric acid with various concentrations of NaBr and Br2) was varied and the intensity of crossover was estimated by measuring stationary voltammograms. To control the precision of experimental data, measurements were taken simultaneously with two identical working electrodes.