阀控密封铅酸蓄电池反应机理分析

Analysis of Reaction Mechanism for VRLA Battery

作为电动车用电池,铅酸蓄电池仍然存在着比能量低、充电接受能力差、活性物质利用率低等缺点,板栅的腐蚀、负极硫酸盐化、析氢、析氧等现象会引起充放电过程中不必要的副反应,这将导致电池容量的损失及衰减。总结了阀控密封铅酸蓄电池(VRLA)及其正负极的反应机理,并对各种反应机理做了比较和评价。详细介绍了负极反应中溶解沉淀机理、固相反应机理和固相反应-溶解沉淀机理,以及正极反应中胶体结构上的PbO2形成机理、液相生成机理和固相生成机理。最后提出了提高铅酸蓄电池性能的几种方法,并对铅酸蓄电池的发展做出了展望。

As power battery for electric vehicle, lead acid battery has many shortcomings such as low specific capacity, the poor ability of charge acceptance and low active material utilization efficiency; corrosion of grid, sulfating of negative electrode, hydrogen and oxygen evolution reaction and other phenomena occur during over charge-discharge and cause the capacity loss or fade to the batteries. The reaction mechanism of VRLA （Valve Regulated Lead Acid） battery and its positive and negative electrode are reviewed, and different mechanisms are discussed and summarized. The dissolution deposition mechanism, solid reaction mechanism, and solid reaction-dissolution deposition mechanism of negative electrode and the PbO2 formation mechanism, liquid phase formation mechanism and solid phase formation mechanism of positive electrode are introduced in detail, respectively. At last, some methods to improve performance of VRLA battery are proposed and the development of VRLA battery is viewed.