阀控式铅酸蓄电池负极汇流排的腐蚀成因及防护对策

Corrosion Cause and Antiseptic Countermeasure of Negative Groups Bar of VRLA

阀控式铅酸蓄电池负极汇流排的腐蚀及脱落是造成电池早期失效的一个重要原因。对早期失效电池负极汇流排的腐蚀形态进行了宏微观分析,对其不同部位(极柱、极群和焊接区)进行了电化学测试。结果表明:在电池浮充条件下负极汇流排处于贫液富氧环境和缺乏足够的阴极保护,形成了汇流排腐蚀的环境;汇流排焊接区的冷却速度与极柱和极群存在显著差异,使焊接区材料的晶粒变为粗大的柱状晶,从而导致其电化学反应活性高于极柱和极群区域,造成其焊接区严重的晶间腐蚀。对此,从3个方面提出了相应的防护对策。

Cailiao Baohu 2015,48( 12),61 ~ 63( Ch). Corrosion morphologies of negative groups bar during the early stage were analyzed in macro and micro scale,and the electrochemical tests were used to investigate various parts including puddle section pole,pole base and weld area. Results showed that when the batteries were in float charging,the negative groups bar was in oxygen-rich and solution-barren environment,and lacked enough negative protection,which formed the environment for groups bar corrosion. Furthermore,the cooling rate of puddle section was much higher than those of bar and negative plate,and so the crystal particle of material in puddle section became large column crystal,which led to more active serious electrochemical reactivity of puddle section,causing seriousintercrystalline corrosion of puddle section in collecting bar.Therefore,the antiseptic countermeasures were put forward from three aspects.