Lead Flow Battery Tests And Failure Mechanism Study

Lead flow batteries have unique advantages in large-scale renewable energy storage.Compared with other flow batteries,the electrolyte of lead flow batteries can be stored in a single storage tank because there is no membrane.However,the lead flow battery is still in the development stage.This thesis studies electrochemical properties of the lead electrolytes,influencing factors of battery cycle life,and failure mechanism of lead flow battery.1.Properties of lead electrolytes with different concentrations and surfactantsWhen the concentration of methanesulfonic acid is 1.00 M,the conductivity decreases with increasing lead-ion concentration.When the concentration of lead-ion is 1.50 M,the conductivity increases with increasing methanesulfonic acid concentration.Kinematic viscosities increase when the concentrations of lead and proton were increased,where the effect of lead concentration is more pronounced.The electrolyte containing sodium lignosulfonate has the lowest charge transfer resistance,and the blank electrolyte has the largest charge transfer resistance,which is 13 times higher.2.Factors on lead flow battery cycle lifeDuring the charge-discharge test,the cycle life of lead flow battery becomes shorter with the increasing charge voltage or the discharge current.The cycle life of lead flow battery with lead dioxide coating as positive electrode is 22.31%higher than with gold.When the additive is cetyltrimethylammonium hydroxide,the battery cycle life was extended by 63.19%from 1197 to 3252 cycles.3.Lead dioxide falling-off mechanism analysisThere were more fall-off lead dioxide particles with increased charge voltage and decreased discharge current.The charge voltage,discharge current,positive substrate material,or surfactants exhibited little effect on the?:?ratio of falled PbO₂.Two kings of falling-off mechanism were proposed.This research analyzes the properties of lead electrolyte,explores the influences of operating conditions,and discusses the failure mechanism,which provides a theoretical basis for future development of lead flow battery.