阀控式铅酸蓄电池负极板的损坏机理

Failure mechanism of negative plates for valve-regulated lead acid batteries

采用电化学表征、循环寿命测试、硫酸铅的含量分析和扫描电子显微镜分析等方法研究了阀控式铅酸蓄电池负极板的损坏机理。研究结果表明 ,随着循环的进行 ,负极板上的硫酸铅晶体颗粒变得越来越大 ,其含量也越来越高 ,负极板电位逐渐正移 ,电池容量相应地逐渐下降。电池和模拟电极研究均表明 ,大颗粒硫酸铅晶体比小颗粒晶体更难还原。因此 ,是大颗粒硫酸铅晶体的积累导致了负极板的容量逐渐下降 。

The failure mechanism of negative plates for valve regulated lead acid batteries was investigated by means of electrochemical characterization, scanning electron microscopy(SEM), cycle life test and analysis of lead sulfate content in negative plates. The results show that the content of lead sulfate become higher and higher and the lead sulfate crystals grow gradually in size with cycling. The negative plate potential shifted to the positive direction gradually and the cell capacity dropped accordingly. The measurements of both battery and simulated electrode indicate that the large crystals are more difficult to be reduced than the small ones. Therefore, the accumulation of large crystals leads to the decrease of negative plate capacity and the battery failure at last.