Combined Separator Based on a Porous Ion-Exchange Membrane for Zinc-Halide Batteries

In this work, we report on a comparative analysis of the bromine permeability for three separator groups under the operating conditions of a non-flow zinc-bromine battery. A new method for the synthesis of porous heterogeneous membranes based on a cation-exchange resin followed by treatment with tetrabutylammonium bromide is proposed. It was shown that the modified membrane significantly reduced the bromine permeability (crossover) with an acceptable increase in the ionic conductivity of the separator group. Leakage currents not exceeding 10-20 mu A/cm(2) were achieved, and the Coulomb efficiency was over 90%. The ionic conductivity (at AC) of a membrane soaked with water was compared for different pretreatment conditions. The frequency dependence of the membrane resistance is shown. The features of the conduction mechanism of the modified membrane are discussed.

Automated summary

In this study, a comparative analysis of bromine permeability for three separator groups in a non-flow zinc-bromine battery was conducted. A new method for synthesizing porous heterogeneous membranes using a cation-exchange resin and tetrabutylammonium bromide treatment was proposed. The results showed that the modified membrane significantly reduced bromine permeability while maintaining acceptable increase in ionic conductivity of the separator group. Leakage currents below 10-20 mu A/cm(2) were achieved, and the Coulomb efficiency was over 90%. The study also compared the AC ionic conductivity of membranes treated with water under different pretreatment conditions, and discussed the conduction mechanism of the modified membrane.