Flooded lead-acid battery and method of making the same
Positive active material pastes for flooded deep discharge lead-acid batteries, methods of making the same and lead-acid batteries including the same are provided. The positive active material paste includes lead oxide, a sulfate additive, and an aqueous acid. The positive active material paste contains from about 0.1 to about 1.0 wt % of the sulfate additive. Batteries using such positive active material pastes exhibit greatly improved performance over batteries with conventional positive active material pastes.
1. A method for making a flooded lead-acid battery comprising:
casting a plurality of positive electrode grids from a first lead-antimony alloy;
casting a plurality of negative electrode grids from a second lead-antimony alloy,
applying a negative active material paste to the plurality of negative electrode grids to form a plurality of negative plates, the negative active material comprising lead oxide;
applying a positive active material paste to the plurality of positive electrode grids to form a plurality of positive plates, the positive active material paste comprising lead oxide, a binder, and a metal sulfate comprising a metal selected from the group consisting of tin, zinc, titanium, calcium, potassium, bismuth, indium, and combinations thereof, wherein the molar ratio of lead to the metal in the positive active material paste is from about from about 450:1 to about 650:1;
arranging the plurality of positive and negative plates in an alternating arrangement in a battery case with the positive and negative plates separated from one another by a plurality of separators;
adding an aqueous electrolyte to the battery case; and
applying a charge across the positive and negative plates, thereby forming the flooded lead-acid battery.
2. The method of claim 1 wherein the metal sulfate is tin sulfate, and the tin sulfate is present in the positive active material paste in an amount from about 0.1 wt % to about 1 wt % on a dry basis.
3. The method of claim 2 wherein the tin sulfate is present in the positive active material paste in an amount from about 0.15 wt % to about 0.2 wt % on a dry basis.
4. The method of claim 2 wherein the tin sulfate is present in the positive active material paste in an amount of about 0.18 wt % on a dry basis.
5. The method of claim 1 further comprising aging the flooded lead-acid battery for a period of time from about 2 months to about 6½ months.
6. The method of claim 1 wherein the first and second lead-antimony alloys comprise between about 2 wt % and 6 wt % of antimony.
7. The method of claim 6 wherein the second lead-antimony alloy contains a lower percentage of antimony than the first lead-antimony alloy.
8. A method for making a flooded lead-acid battery comprising:
casting a plurality of positive electrode grids from a first lead-antimony alloy;
casting a plurality of negative electrode grids from a second lead-antimony alloy, wherein the second lead-antimony alloy contains a lower percentage of antimony than the first lead-antimony alloy;
applying a negative active material paste to the plurality of negative electrode grids to form a plurality of negative plates, the negative active material comprising lead oxide;
applying a positive active material paste to the plurality of positive electrode grids to form a plurality of positive plates, the positive active material paste comprising lead oxide, a binder, and tin sulfate, wherein the tin sulfate is present in the positive active material paste in an amount from about 0.1 wt % to about 1 wt % on a dry basis;
arranging the plurality of positive and negative plates in an alternating arrangement in a battery case with the positive and negative plates separated from one another by a plurality of separators;
adding an aqueous electrolyte to the battery case; and
applying a charge across the positive and negative plates, thereby forming the flooded lead-acid battery.
9. The method of claim 8 wherein the tin sulfate is present in the positive active material paste in an amount from about 0.15 wt % to about 0.2 wt % on a dry basis.
10. The method of claim 8 wherein the tin sulfate is present in the positive active material paste in an amount of about 0.18 wt % on a dry basis.
11. The method of claim 8 further comprising aging the flooded lead-acid battery for a period of time from about 2 months to about 6½ months.
12. The method of claim 8 wherein the first and second lead-antimony alloys comprise between about 2 wt % and 6 wt % of antimony.
13. A positive plate for a flooded lead-acid battery comprising an unclad cast electrode grid made of a lead-antimony alloy comprising from about 2 to about 11 wt % antimony, wherein the unclad cast electrode grid is coated with a positive active material paste comprising lead oxide, a binder, and tin sulfate, wherein the tin sulfate is present in the positive active material paste in an amount from about 0.1 wt % to about 1 wt % on a dry basis.
14. The positive plate of claim 13 wherein the tin sulfate is present in the positive active material paste in an amount from about 0.15 wt % to about 0.2 wt % on a dry basis.
15. The positive plate of claim 13 wherein the tin sulfate is present in the positive active material paste in an amount of about 0.18 wt % on a dry basis.
16. The positive plate of claim 13 wherein lead-antimony alloy comprises between about 2 wt % and 6 wt % of antimony.
17. A method for making a positive plate for a flooded lead-acid battery comprising:
casting a positive electrode grid from a lead-antimony alloy, wherein the lead-antimony alloy comprises between about 2 wt % and 6 wt % of antimony;
applying a positive active material paste to the cast positive electrode grid, the positive active material paste comprising lead oxide, a binder, and tin sulfate, wherein the tin sulfate is present the positive active material paste in an amount from about 0.1 wt % to about 1 wt % on a dry basis.
18. The method of claim 17 wherein the tin sulfate is present in the positive active material paste in an amount from about 0.15 wt % to about 0.2 wt % on a dry basis.
19. The method of claim 17 wherein the tin sulfate is present in the positive active material paste in an amount of about 0.18 wt % on a dry basis.