| 摘要 |
PROBLEM TO BE SOLVED: To reconcile the higher efficiency of chemical conversion charging and the prevention of deep reduction in charge and discharge cycle life by setting one mesh of the expanded metal grating of a positive electrode plate to a specified area, and including red lead of a specified ratio in a mixed powder of lead and lead oxide formed by kneading a paste to be applied with water and diluted sulfuric acid. SOLUTION: When a mixed powder of lead and lead oxide in an active material paste contains 10-30% of red lead, chemical conversion efficiency of red lead, improvement in initial capacity characteristic and prevention of a significant reduction in life in repeat of deep charge and discharge are realized. It is formed of reciprocating type or rotary type, and the area per mesh controlled by the length and transverse expanding length of the slit extended in the mesh of an expanded metal grating is set to 40-150 mm<2> , so that the reduction in deep charge and discharge cycle life can be remarkably suppressed. The expanded metal grating frame is preferably twisted with the grating frame as the axis, so that the adhesion between the active material and the grating frame can be kept even after the progress of softening of the positive electrode active material, and the effect can be more enhanced. |
