Corrosion resistant positive grid for lead-acid batteries
A battery grid comprising a continuous cast and mechanically deformed lead-based alloy that comprises lead and silver and is essentially free of calcium, wherein the silver is at a concentration that is in a range of about 0.003 to about 0.015 weight percent, and has a predominant equiaxed grain structure that comprises grain sizes that are in a range of about 0.1 to about 5 microns. Other alloy constituents include bismuth at a concentration that is in a range of about 0.003 to about 0.002 weight percent and tin at a concentration that is in a range of about 0.2 to about 1.8 weight percent. A process for making strip of said alloy for use in manufacturing said grid. A battery comprising said grid.
1. A battery grid comprising a continuous cast and mechanically deformed lead-based alloy that comprises lead and silver and is essentially free of calcium, wherein the silver is at a concentration that is in a range of about 0.003 to about 0.015 weight percent, and has a predominant equiaxed grain structure that comprises grain sizes that are in a range of about 0.1 to about 5 microns.
2. The battery grid of claim 1 wherein the silver concentration range is from about 0.004 to about 0.011 weight percent.
3. The battery grid of claim 1 wherein the continuous cast and mechanically deformed lead-based alloy consists essentially of lead and silver.
4. The battery grid of claim 1 wherein the continuous cast and mechanically deformed lead-based alloy further comprises bismuth at a concentration that is in a range from about 0.003 to about 0.02 weight percent.
5. The battery grid of claim 4 wherein the bismuth concentration range is from about 0.005 to about 0.015 weight percent.
6. The battery grid of claim 4 wherein the continuous cast and mechanically deformed lead-based alloy consists essentially of lead, silver, and bismuth.
7. The battery grid of claim 1 wherein the continuous cast and mechanically deformed lead-based alloy further comprises tin at a concentration that is in a range of about 0.2 weight percent to about 1.8 weight percent.
8. The battery grid of claim 7 wherein the tin concentration range is from about 0.4 to about 1.5 weight percent.
9. The battery grid of claim 8 wherein the tin concentration range is from about 0.5 to about 1 weight percent.
10. The battery grid of claim 7 wherein the continuous cast and mechanically deformed lead-based alloy consists essentially of (a) lead, silver, and tin or (b) lead, silver, bismuth, and tin.
11. The battery grid of claim 1 wherein the lead is at a concentration that is at least 98.000%.
12. The battery grid of claim 1 wherein the battery grid consists of the continuous cast and mechanically deformed lead-based alloy.
13. The battery grid of claim 1 wherein at least about 75% by weight of the continuous cast and mechanically deformed lead-based alloy has an equiaxed grain structure.
14. The battery grid of claim 1 wherein at least about 95% by weight of the continuous cast and mechanically deformed lead-based alloy has an equiaxed grain structure.
15. The battery grid of claim 1 wherein the mechanical deformation is accomplished by rolling or forging.
16. A lead-acid battery comprising a container and, within the container, at least one positive plate, at least one negative plate, and at least one separator separating each positive and negative plate, wherein the positive plate comprises a battery grid comprising a continuous cast and mechanically deformed lead-based alloy that comprises lead and silver and is essentially free of calcium, wherein the silver is at a concentration that is in a range of about 0.003 to about 0.015 weight percent, and has a predominant equiaxed grain structure that comprises grain sizes that are in a range of about 0.1 to about 5 microns.
17. The lead-acid battery of claim 16 wherein the silver concentration range is from about 0.004 to about 0.011 weight percent.
18. The lead-acid battery of claim 16 wherein the continuous cast and mechanically deformed lead-based alloy consists essentially of lead and silver.
19. The lead-acid battery of claim 16 wherein the continuous cast and mechanically deformed lead-based alloy further comprises bismuth at a concentration that is in a range from about 0.003 to about 0.02 weight percent.
20. The battery grid of claim 19 wherein the bismuth concentration range is from about 0.005 to about 0.015 weight percent.
21. The battery grid of claim 19 wherein the continuous cast and mechanically deformed lead-based alloy consists essentially of lead, silver, and bismuth.
22. The lead-acid battery of claim 16 wherein the continuous cast and mechanically deformed lead-based alloy further comprises tin at a concentration that is in a range of about 0.2 weight percent to about 1.8 weight percent.
23. The battery grid of claim 22 wherein the tin concentration range is from about 0.4 to about 1.5 weight percent.
24. The battery grid of claim 23 wherein the tin concentration range is from about 0.5 to about 1 weight percent.
25. The battery grid of claim 23 wherein the continuous cast and mechanically deformed lead-based alloy consists essentially of (a) lead, silver, and tin or (b) lead, silver, bismuth, and tin.
26. The lead-acid battery of claim 16 wherein the lead is at a concentration that is at least 98.000%.
27. The lead-acid battery of claim 16 wherein the battery grid consists of the continuous cast and mechanically deformed lead-based alloy.
28. The lead-acid battery of claim 16 wherein at least about 75% by weight of the continuous cast and mechanically deformed lead-based alloy has an equiaxed grain structure.
29. The lead-acid battery of claim 16 wherein at least about 95% by weight of the continuous cast and mechanically deformed lead-based alloy has an equiaxed grain structure.
30. The lead-acid battery of claim 16 wherein the mechanical deformation is accomplished by rolling or forging.