阀控铅酸蓄电池正极板栅的电化学行为

Electrochemical behavior of positive grid of VRLA battery

采用循环伏安曲线、电化学阻抗谱和Tafel曲线研究了阀控铅酸蓄电池正极板栅的电化学行为。不同扫描速度下的循环伏安曲线表明,扫描速度增加,体系的可逆性逐渐变差,峰值电流随扫描速度增大而升高。不同温度下循环伏安曲线表明,随着温度的升高,析氢量和析氧量逐渐增多,氧化峰与还原峰的峰值电流随温度升高而增大,电化学极化减小。电化学阻抗谱表明,板栅的耐腐蚀性和电导率与电荷转移电阻有关。Tafel曲线表明,高温时效工艺的正极板栅更容易腐蚀。

The electrochemical behavior of positive grids of VRLA batteries is investigated by cyclic voltammograms（CV）,electrochemical impedance spectroscopy（EIS） and Tafel curves.CV curves with different scanning rates show that the reversibility of the system decreases due to the increased scanning rates.The peak current increases with increasing of scanning rates.CV curves at different temperatures reveal that the evolution of hydrogen and oxygen increases gradually as a result of temperature increasing.However,the currents of oxidation and reduction peaks increase,and the electrochemical polarization decreases.Electrochemical impedance spectroscopy（EIS） shows that the corrosion resistance and electrical conductivity of the grids are related to the charge transfer resistance.Tafel curves exhibit that positive grids with high temperature age hardening are easier to be corroded.