Abstract: In order to improve the electrochemical performance of zinc electrodes in alkaline batteries, several sonochemically modified zinc powders were successfully prepared in different concentrations of Y(NO3)3 solutions by means of ultrasonic immersion. Moreover, the formation of Y(OH)3/Y2O3 on modified zinc powder, the corrosion inhibition and cyclic performance of corresponding zinc electrodes were investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical and other techniques. The results showed that Y(OH)3/Y2O3 particles were uniformly distributed on sonochemically modified zinc powder with 0.036 mol·L-1 Y(NO3)3 solution. Simultaneously, the yttrium compounds grew preferentially on the defect sites of zinc powder surface, and prevented the dissolution and diffusion of zincate anions into alkaline electrolyte during the electrochemical process. All these results contributed to the facts that the inhibition efficiency of zinc electrode achieved 79.6%, and differential value between anodic and cathodic peak potentials decreased by 285 mV at the 20th cyclic voltammogram. Simulated silver-zinc batteries were assembled using bare zinc powder and the zinc powder modified with 0.036 mol·L-1 Y(NO3)3 solution. According to the detections of the batteries at a high discharge current density of 250 mA·cm-2, capacity loss of zinc electrode containing the modified zinc powder reached only 62.7 mAh·g-1 from the 1st to 30th cycles, and discharge capacity of 322.6 mAh·g -1 was still reserved after 50 cycles. Therefore, a conclusion was drawn that discharge capacity and cycle life of zinc electrodes were obviously enhanced owing to the application of sonochemically modified zinc powder.

Key words: Modified zinc powder, Ultrasonic immersion, Rare earth yttrium, Electrode, Corrosion inhibition, Cyclic performance