Evaluation the Role of Carbon in the Polarization Resistance of Silver Electrodes Used in the Silver Oxide-Zinc Cells

Abstract Zinc - silver oxide batteries from components such as the negative electrode (zinc plates)¡ the positive electrode (silver plates)¡ separators (cellulose¡ slufaty¡ cotton)¡ electrolytes (potassium hydroxide) were maded. Therefore¡ the performance of this batteries depends to the performance of the mentioned factors. In this study¡ effects of carbon content on the polarization resistance of silver electrodes in the KOH environment of zinc - silver oxide batteries was investigated. For this purpose¡ initially three Ag electrodes (positive plate) containing 5¡ 10 and 15 wt. % carbon powder was prepared. Then¡ all three silver electrodes were sintered at temperature 500C for 13 minutes. Potentiodynamic polarization and electrochemical impedance spectroscopy methods were used in the 1.4% KOH solution to evaluate the polarization resistance of Ag electrodes. Scanning electron microscopy was used to examine the microstructure of electrodes and point analysing. Electrochemical tests results showed that with increasing carbon content¡ polarization resistance of silver electrodes reduced in the KOH. SEM images were showed that with increasing carbon content¡ the amount and size of pores increased in the electrodes. Also¡ point analysis results has implies on reduce in the amount of carbon and oxygen¡ with the increasing of carbon content in electrodes.