Impact of Deposition Condition on the Morphology and Electrochemical Performance of Deposited F-Doped PbO2 on Graphite Substrate in Primary PbO2-Zn Battery

Abstract

The impact of deposition process parameters (temperature, current density, Pb2+ concentration, and time of deposition) on morphology, electrical resistance, and discharge performance of a graphite/PbO2 cathode in a PbO2/zinc primary battery was investigated. The morphology, architecture, and phase composition of the PbO2 deposits were studied by FESEM, EDX, and XRD. The AC impedance and discharge tests were utilized for the exploration of the interfacial process and discharge performance of PbO2 deposits. The results indicate that the increment in temperature and decrease in current density leads to increased growth of PbO2 deposits with mainly β phase, formation of porous architecture, and a decrease in the charge transfer resistance (Rct). Also, with an increase in the deposition time to 30 min the Rct is increased due to the formation of PbO2 deposit with more uniform and compact structure. The deposition from 0.1 mol l‒1 Pb2+ solutions results in the formation of flower-like grains, a more porous surface, and lower Rct. However, because of concentration polarization, the PbO2 deposit prepared from 0.5 mol l‒1 of Pb2+ solutions, 55 °C temperature, 40 mA cm‒2 current density, and 15 min deposition time shows the best discharge performance.