During operation in idling stop-start vehicles, flooded lead–acid batteries are unlikely to remain fully-charged and thus stratification of the electrolyte solution may readily occur. In such a situation, the cell reaction is concentrated at the top of the plates and degradation of the active material is acceralated. Hitachi Chemical has succeeded in suppressing acid stratification through the introduction of a new structure for the separator that combines conventional technology with a special separator. In order to elucidate the mechanism by which acid stratification is hindered, an investigation has been made of the sedimentation behaviour of sulfate ions in the direction of gravity and their diffusion behaviour in the horizontal direction.

Toshio Shibahara
Hitachi Chemical Co.,Ltd. Tsukuba Research Laboratory
Senior Researcher

Biography: Toshio Shibahara is a senior researcher in the Tsukuba Research Laboratory of Hitachi Chemical. He has been as engaged in the research and development of lead–acid batteries for 23 years. Currently, Toshio is studying of the performance of lead–acid batteries for Idling Stop-Start Vehicles.

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