Polypyrrole (PPy) thin film electrode was galvanostatically synthesized and characterized in 0.1 M HCI on graphite electrode as cathode materials for the aqueous-based rechargeable zinc batteries. The charge/discharge characteristics of PPy and zinc electrode in 0.1 M ammonium chloride and in the 0.1 M ammonium chloride with addition of 0.1 M sodium citrate were investigated. Electrochemical characteristic of possible Zn vertical bar PPy cell in chloride/citrate containing electrolyte was discussed and simulated. (C) 2008 Elsevier Ltd. All rights reserved.