Physical Changes in Positive Active Mass during Deep Discharge‐Charge Cycles of Lead‐Acid Cell

The positive active mass of a pasted‐type lead‐acid cell changes morphologically to a great extent during deep discharge‐charge cycles. In order to reduce these changes, the effect of compression on the active mass has been studied. When compression is applied to a positive plate, expansion of the positive active mass is suppressed and the structural changes become smaller. Therefore, the cycle life of the positive plate increases remarkably. The reason why the cycle life increases by compression is due to suppression of the decrease in cohesion between particles.