| abstract |
The invention relates to a semi-permeable membrane for a lead-acid battery. The membrane has a microporous structure comprising a first polymer and a second polymer intimately mixed together, and is characterized by the fact that the first polymer is chosen from among the following polymers: polyacrylic acid, polymethacrylic acid, a copolymer with a high proportion of acrylic or methacrylic acid, a mixture of these polymers, the average molecular weight of these polymers lying between 10,000 and a few millions and preferably between 50,000 and one million, the second polymer being soluble in water. |