Performance of porous zinc electrode in alkaline secondary battery systems suffers mainly from shape change and dendrite growth. Polyaniline coating in direct contact with porous zinc electrode was found to restrict zincate movement away from the test electrode, which otherwise may lead to a decrease in electrode surface area (shape change of the electrode) on repeated cycling. Constant current charge/discharge cycles of the blank and polyaniline-coated zinc electrodes have been carried out to assess the performance of the polymer film. It was found that a fibrous network of polyaniline coating allows OH- ions and restricts the diffusion of zincate ions. (c) 2005 The Electrochemical Society.