An in-depth study of lead dioxide formation in nitrate and methanesulfonate solutions by in situ analysis and numerical model

Abstract

An in-depth understanding of PbO2 formation is critical for the development of PbO2 electrodes preparation and battery applications. In this study, incorporating in situ atomic force microscopy, electrochemical quartz crystal microbalance and numerical modelling technologies, the details in nitrate and methanesulfonate electrolytes are observed and simulated during electrodeposition. The behavior of PbO2 deposition in soluble media is observed in situ by atomic force microscopy for the first time in this study. Both in nitrate and methanesulfonate solutions, the PbO2 deposits are initially formed only by circle-like phase alone, and then pyramidal phase is formed or the two phases are identical. If the deposition is carried out for longer time, the growth centers of phase with slower grow rate can be covered by another phase. The ratio of mass to electrical charge for PbO2 deposition onto gold in methanesulfonate electrolyte attains 0.85 mg C−1, which is bigger than nitrate electrolyte. Variations of species concentration distribution and oxygen evolution current density are simulated in this study. The influence and concentration distribution of Pb(CH3SO3)+ are investigated probably for the first time in model.