To improve a bonded state between a current collector and an active material by depositing a specific amount of an alkaline solution on a current collector made of a lead-calcium-tin alloy containing a specific amount of tin and then filling the current collector with paste.
An alkaline solution having concentration preferably between 2 and 12mol/liter is deposited on a current collector made of a lead-calcium-tin alloy, preferably containing 0.8wt.% or more of tin. The current collector is preferably treated by use of an alkaline aqueous solution for facilitating the dissolving reaction of the lead of the current collector and maintaining a well- bonded state between the current collector and an active material. The current collector so treated is filled with paste made of water, sulfuric acid and an additive added to and kneaded with lead powder made of an oxide, for example, containing several percent weight of tin. The current collector to be used in this case is fabricated by applying an expansion process to a sheet of led- calcium-tin alloy, and the surface thereof is polished.
TAKAMA TETSUO
SHIYUU KETSUSEI
YOSHIDA TAKAMASA
