Glass-based battery separator

A battery separator comprising a composite, comprising the following components:

• (A) 5 to 95% by weight of at least one carrier material consisting of glass fibres, the carrier material being selected from the group consisting of nonwovens, layered fabrics, knitted fabrics, woven fabrics and/or mixtures thereof;
• (B) 5 to 95% by weight of at least one glass flake with an average thickness of 0.05 μm to 30 μm;
• (C) 0 to 95% by weight of at least one binder;
• components (A), (B) and (C) adding up to 100% by weight, and
• the battery separator having a porosity in the range of 10 to 70% and a total thickness of 0.01 mm to 0.5 mm;
• wherein the at least one glass flake (B) has the following composition:
• 20 to 85% by weight of SiO2, 20 to 70% by weight of B2O3, 0 to 16% by weight of Na2O, 0 to 16% by weight of Li2O, 0 to 5% by weight of Al2O3, 0 to 5% by weight of ZrO2, 0 to 1% by weight of SnO2, 0 to 1% by weight of TiO2, 0 to 1% by weight of K2O, 0 to 1% by weight of MoO3, up to 2% by weight of refining agents, the proportions of the mentioned components adding up to 100% by weight and the proportion of ZnO, MgO, CaO, and BaO in the glass flake (B) is less than 15% by weight, relative to the total mass of the glass flake (B), and the proportion of Fe2O3 and Sb2O3 is less than 15% by weight, relative to the total mass of the glass flake (B).