铅酸蓄电池正极放电过程控制因素研究

Studies on the control factor in discharge process of positive electrode in lead acid batteries

用线性电位扫描、恒电流阶跃、计算机模拟放电曲线等方法，研究了涂膏式铅酸蓄电池正极的放电行为。结果表明，正极活性物质ＰｂＯ２的还原反应是可逆的，峰电流Ｉｐ与扫描速度平方根ｖ１／２的关系为一通过原点的直线。峰电位φｐ不随扫描速度的变化而改变。峰电流Ｉｐ随硫酸溶液浓度的增加而增加，但随电解液中硫酸铵浓度的增加而减小。电解液的搅拌速度对峰电流Ｉｐ毫无影响。证实涂膏式铅酸蓄电池正极的放电过程受电极活性物质微孔内Ｈ＋离子扩散控制。恒电流阶跃实验证实电极电位φ与ｌｎ（τ１／２－ｔ１／２）符合直线关系，而且直线的斜率与理论值十分接近。

The discharge behavior of positive electrode in pasted type lead acid batteries has been investigated by using methods of linear sweep voltammetry,constant current chronopotentiometry and computer simulation of the discharge curve etc.The experimental results showed that the reductive reaction of the positive active mass was a reversible reaction.The peak current I p increased with the raising of the sulfuric acid concentration and decreased with the raising of the concentration of ammonia sulfate.It confirmed that the discharge process was not controled by the diffusion of the SO 2- 4 ion or the HSO - 4 ion but the H + ion.The peak current I p was not in relation with the stirring speed of the sulfuric acid solution.By the computer simulation of the discharge curve,it is further confirmed that the discharge process is controlled by the diffusion of the H + ions within the inner pores of the plate.