PURPOSE: To realize long term storing only through improvement of alloy composition of substrate by filling the lattice type substrate where aluminum of specified amount or more is contained into the Pb-Sb alloy with an active substance.

CONSTITUTION: A substrate where 0.01wt% of aluminum is contained to the Pb- Sb alloy is filled with an active substance. For example, the lattice type substrate surface consisting of 2.5% Sb-0.2% Al-Pb alloy is filled with an unformed active substance. Thereafter, it is placed in a forming reservior. Thus, forming is carried out through charging and discharging. It is then washed by water and is dried up to form a pole plate. When aluminum is added to the Pb-Sb alloy, a crystal composition becomes fine and the interface of lattice type substrate and active substance becomes dense. But if amount of addition is under 0.01% aluminum cannot show its full performance. In case aluminum of 1% of more is added, a solid solution is not formed at the interface between Pb-Sb alloy, forming only mechanical mixing. Therefore, desired amount of addition of aluminum is about 0.2∼0.8%.