Effect of Y(OH) 3 microparticles on the electrochemical performance of alkaline zinc electrodes

Abstract

This work focused on the zinc powder coated with Y(OH) 3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems. Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH) 3 microparticles in direct contact with zinc powder. Electrochemical properties of zinc electrodes containing Y(OH) 3 microparticles were discussed through the measurements of potentiodynamic polarization and cyclic voltammetry. Simultaneously, the test cells making use of such modified zinc powder were assembled to further evaluate the availability of Y(OH) 3 microparticles in improving the cycle properties of zinc electrodes. It was found that good alkaline environment generated by ultrasonic irradiation of high power led to the formation of Y(OH) 3 microparticles on the surface of modified zinc powder due to high-energy jets of immersion solution. In particular, the Y(OH) 3 microparticles formed with the ultrasonic power of 440 W made the greatest contributions to hinder the corrosion of zinc electrode and the dissolution of zinc oxidation products in alkaline electrolyte as compared with other power parameters. Besides, the detections of assembled cells at a high discharge current density of 250 mA/cm 2 revealed that the Y(OH) 3 microparticles obtained with ultrasonic power of 440 W provided the alkaline zinc electrode with low capacity loss and persistent cycle behavior. The great improvement over the corrosion behavior and cycle properties of zinc electrode is possibly ascribed to the uniform distribution of Y(OH) 3 microparticles on the surface of modified zinc powder.