In order to improve the electrochemical performance of lead-acid batteries for energy storage, SnSO4 and Sb2O3 were selected as additives to form positive plates. The effects of these additives on the composition and the microstructure of the positive plate were investigated. The content of PbSO4 and hydrated PbO2 in positive active material (PAM) of lead acid batteries have been characterized by chemical analysis and X-ray photoelectron spectroscopy (XPS). Experiment results prove that the contents of hydrated PbO2 gradually decrease with the increase of PbSO4, and the maximum depth-of-discharge (DoD) for electrodes is determined. Through contrastive analysis of different types of electrodes, the relation between the content of hydrated PbO2 and cycle life has been obtained. Using this method, the cycle life of new batteries could be predicted rapidly. (C) 2017 The Electrochemical Society. All rights reserved.