PURPOSE: To improve weight energy efficiency as well as reduce the weight ratio of grid body without reducing weight output efficiency at the time of high-rate discharge by limiting the thickness and notch width of an expanding grid body used in a negative electrode plate within a specific range.
CONSTITUTION: An expanding grid body is formed with a notch width of 0.7∼ 1.3mm, leaving the current collecting master bone 1 and the current collecting lug 2 intact, by using 0.5∼1.0 thick lead or lead alloy thin plate. Then, a negative electrode plate with a grid, weight ratio of 0.15∼0.30 is made up of the grid body and an active material. Then, an electrode plate group is built up by combining the negative electrode plate with a positive electrode plate consisting of lead or lead alloy cast grid bodies.
IKEDA SEIICHIROU
KOUNO KEN
