Abstract: An additive for producing positive active compositions for lead accumulators based on finely divided 4-basic lead sulphate having an average particle size of less than about 3 ?m and also finely divided silica, where the additive additionally contains red lead (2PbO.PbO2), is described. The finely divided silica prevents, in particular, agglomeration of the particles of the 4-basic lead sulphate, while the red lead leads to an optimized distribution of all constituents of the additive in the battery paste. The use of red lead also gives a cost advantage. Despite the replacement of part of the 4-basic lead sulphate by red lead, the properties achieved in the later use in battery operation are no worse. Thus, the batteries display, for example, improved charging behavior and a higher high-current discharging stability.

Abstract: An additive for producing positive active compositions for lead accumulators based on finely divided 4-basic lead sulphate having an average particle size of less than about 3 ?m and also finely divided silica, where the additive additionally contains red lead (2PbO.PbO2), is described. The finely divided silica prevents, in particular, agglomeration of the particles of the 4-basic lead sulphate, while the red lead leads to an optimized distribution of all constituents of the additive in the battery paste. The use of red lead also gives a cost advantage. Despite the replacement of part of the 4-basic lead sulphate by red lead, the properties achieved in the later use in battery operation are no worse. Thus, the batteries display, for example, improved charging behaviour and a higher high-current discharging stability.

Abstract: The present invention is an additive for producing a positive active material for lead-acid storage batteries on the basis of finely divided tetrabasic lead sulfate. The additive contains a tetrabasic lead sulfate of an average particle size less than about 3 ?m as well as finely divided hydrophobic silicic acid for preventing agglomeration of the particles of the tetrabasic lead sulfate. During maturation, this additive ensures the formation of the structure of a tetrabasic lead sulfate crystal with a very narrow bandwidth of crystal sizes and a very homogeneous distribution. In the subsequent electrochemical formation to lead oxide, this leads to particularly efficient lead-acid storage batteries. Furthermore, the invention relates to a method of making the additive according to the invention as well as its advantageous use in the positive material for the maturation and drying of plates in the production of lead-acid storage batteries.

Abstract: Described is an additive for producing the positive active material for lead-acid storage batteries on the basis of finely divided tetrabasic lead sulfate. The additive contains a tetrabasic lead sulfate of an average particle size smaller than about 3 &mgr;m as well as finely divided silicic acid for preventing an agglomeration of the particles of the tetrabasic lead sulfate. During maturation, this additive ensures the formation of the structure of a tetrabasic lead sulfate crystal with a very narrow bandwidth of crystal sizes and a very homogeneous distribution. In a subsequent electrochemical formation to lead oxide, this leads to particularly efficient lead-acid storage batteries. Furthermore, the invention relates to a method of making the additive according to the invention as well as its advantageous use in the positive material for the maturation and drying of singled and not singled plates in the production of lead-acid storage batteries.