Lead-acid battery electrode and method of manufacture
AssigneeGeneral Motors Corporation
InventorsRomeo R. Witherspoon, Armand R. Poirier
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AssigneeGeneral Motors Corporation
InventorsRomeo R. Witherspoon, Armand R. Poirier
Estimating the term…
Positive plates are prepared by forming partially oxidized tetrabasic lead sulfate (4 PbO.sub.n . PbSO.sub.4) having at least a part of the oxide (PbO.sub.n) portion in the form of alpha lead dioxide (.varies. - PbO.sub.n), and forming beta lead dioxide (B-PbO.sub.2). Next the oxidized tetrabasic lead sulfate (OXYTTB) and the beta lead dioxide are intermingled in a wet mixture. The wet mixture is applied to the oxidized surface of a lead support substrate. Then, it is heated and pressed for a time and at a temperature and compressive load sufficient to form an adhered or retained coating of active material on the substrate. The OXYTTB is formed by reaction of tetrabasic lead sulfate with magnesium hydroxide and sodium persulfate. Preferably, beta lead dioxide is formed by reacting red lead oxide (Pb.sub.3 O.sub.4) with nitric acid to provide an oxidation product, at least a major portion of which is beta PbO.sub.2, and which has a surface area of at least 10 m.sup.2 /gram.
A pre-charged positive electrode comprising at least about 50% by weight at least partially oxidized tetrabasic lead sulfate (4PbO.sub.n .PbSO.sub.4) intermingled with beta lead dioxide (.beta.-PbO.sub.2), the beta lead dioxide being present in an amount up to about 50% by weight wherein the oxide (PbO.sub.n) portion of the tetrabasic lead sulfate is at least in part alpha lead dioxide (alpha-PbO.sub. 2).
A lead-based pre-charged active material, comprising at least about 50% by weight at least partially oxidized tetrabasic lead sulfate (4PbO.sub.n .PbSO.sub.4) beta lead dioxide (.beta.-PbO.sub.2), the beta lead dioxide being present in an amount up to about 50% by weight wherein the oxide (PbO.sub.n) portion of the tetrabasic lead sulfate is at least in part alpha lead dioxide (alpha-PbO.sub. 2).
A method of making a positive plate for a lead-acid battery comprising:
Dependencies are inferred from the claim text.