Electrochemical behavior of potassium ferrate(VI) (K2FeO4) coated with different content of 2,3-Naphthalocyanine (H(2)Nc) is investigated as a function of exposure time in electrolyte. Galvanostatic discharge curves indicate that the stability of K2FeO4 cathode is improved by coating a layer of H(2)Nc. In short exposing time of 3 h, the capacity of coated K2FeO4 shows slight decrease with increase of H(2)Nc content. But in longer exposing time of more than 6 h, the K2FeO4 cathode coated with more than 2% H(2)Nc shows better capacity. Open-circuit potential curves indicate that the stability of K2FeO4 increases with increasing H(2)Nc content. Electrochemical impedance spectroscopy (EIS) results reveal that H(2)Nc partially hinders the contact between K2FeO4 and the aqueous media, and enhances the ability of electron transfer in the electrode, which are responsible for the enhancement of K2FeO4 stability. (C) 2012 Elsevier B.V. All rights reserved.