铅酸蓄电池正负极低温充电容量和极化特征

Polarization and charge capacity of positive negative plates of lead acid battery at low temperature

探讨了多种因素（即温度，循环次数，充电速率，负极膨胀剂，电解液密度等）对铅蓄电池低温充电时正负极的电位、时间曲线和容量的影响。实验中发现在－２０℃下，以木素为膨胀剂的负极在低温充电初期，需有５个～１０个充放循环的活化过程，才能达到其稳定低温充电容量，而正极达到其稳定低温充电容量只需两个循环。低温下负极恒流充电时，中期极化增加较快，后期电位出现明显的析氢平台。而正极充电初期就有较大的极化，经过一段略微的下降后电位呈现平稳上升的态势。－２０℃下铅蓄电池的低温充电容量虽受控于负极，但正极活性物质在低温充电过程中易脱落。

The capacity and potential change of positive and negative electrodes of lead acid battery during low temperature charge has been investigated.Many factors that influence the low temperature charge,such as temperatures,cycle numbers,electrolyte density,current density and negative expander etc.have been considered.It has been observed that negative electrode containing lignin needs 5～10 initial charge and discharge cycles at low temperature to reach its stable low temperature charge capacity,while it only needs about 2 cycles for positive electrode.At low temperature(-20℃)and a given constant charge current,the polarization potential of negative electrode rises faster at middle stage and appears an obvious plateau of hydrogen evolution at later stage.However,the polarization potential of positive electode rises faster at initial stage and then decreases slightly and at last increases monotonously.Although at low temperature -20℃ ,the charge capacity of the battery is limited by negative electrodes,shedding of positive active material during low temperature charge also becomes a serious problem for lead acid battery.