Hitachi Chemical Company, Ltd.

Masatoshi Toduka

Koji Kogure

Masanori Sakai

Shinsuke Kobayashi

Satoru Takahashi

Satoshi Minoura

Toshio Shibahara

On each negative plate (), a non-woven fabric () composed of fibers of at least one material selected from a group of materials comprising glass, pulp and polyolefins comes into contact with the entire surface of the plate without being integrated with the plate. Each negative plate (), which is in contact with the non-woven fabric (), is contained in an envelope separator () comprising a microporous synthetic resin sheet, and is laminated with a positive plate (). The non-woven fabric is manufactured through papermaking process in which glass fibers, pulp and silica powder are preferably used and dispersed in water as the main components.

Lead acid battery

A lead-acid battery improving the charge acceptance in an initial stage, suppressing the decrease of the charge acceptance for a long time use of the battery and having a long life is provided. In a lead-acid battery using a paste type negative plate prepared by filling a past form negative active material using a lead powder as a starting material in a collector made of a lead alloy, a flake graphite and a condensate of bisphenols and aminobenzene sulfonic acid are contained in the negative active material. The average primary particle diameter of the flake graphite is 10 &#x3bc;m or more and 220 &#x3bc;m or less, preferably, 100 &#x3bc;m or more and 220 &#x3bc;m or less. The content of the flake graphite is preferably from 0.5 mass parts to 2.7 mass parts and, more preferably, from 1.1 mass parts to 2.2 mass parts based on 100 mass parts of the negative active material (spongy metallic lead) in a fully charged state.

Lead-acid battery

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Tokyo, Japan

Masatoshi Toduka