NEGATIVE PLATE FOR LEAD ACID BATTERY
Capacitor pastes for flooded deep discharge lead-acid batteries include lead oxide, a carbon additive, and an aqueous acid. The capacitor paste contains lead and carbon in a lead to carbon mass ratio of about 5:1 to 82:1. Hybrid negative plates for flooded deep discharge lead-acid batteries can be made using such pastes in combination with traditional pastes. The hybrid negative plates include a capacitor paste on a bottom portion of the plate, and a traditional paste on the remainder of the plate. Batteries using the capacitor paste and hybrid plates exhibit improved performance over batteries with conventional plates and pastes and require less overcharge to prevent electrolyte stratification.
1 . A negative electrode plate for a flooded lead-acid battery comprising:
an electrode grid defining first and second grid regions, the second grid region oriented below the first grid region;
a first negative active material comprising lead and coating the first grid region; and
a second negative active material comprising carbon and coating the second grid region.
2 . The negative electrode plate of claim 1 , wherein the second grid region comprises between 5% and 95% of the area of the electrode grid.
3 . The negative electrode plate of claim 2 , wherein the second grid region comprises between 15% and 50% of the area of the electrode grid.
4 . The negative electrode plate of claim 1 , wherein the second negative active material comprises carbon selected from the group consisting of carbon black, graphite, activated carbon, and combinations thereof.
5 . The negative electrode plate of claim 4 , wherein carbon black, graphite, and activated carbon are present in a 1:1:1 weight ratio.
6 . The negative electrode plate of claim 4 , wherein carbon black, graphite, and activated carbon are present in a 1:1:4 weight ratio.
7 . The negative electrode plate of claim 1 , wherein the second negative active material comprises carbon and lead and has a lead to carbon mass ratio of about 5:1 to about 82:1.
8 . The negative electrode plate of claim 7 , wherein the second negative active material has a lead to carbon mass ratio of about 30:1.
9 . A flooded lead-acid rechargeable battery comprising:
at least one positive electrode plate;
at least one negative electrode plate comprising:
an electrode grid defining first and second grid regions, the second grid region oriented below the first grid region;
a first negative active material comprising lead and coating the first grid region; and
a second negative active material comprising carbon and coating the second grid region; and
an electrolyte.
10 . The flooded lead-acid battery of claim 9 , wherein the second grid region comprises between 15% and 50% of the area of the electrode grid.
11 . The flooded lead-acid battery of claim 9 , wherein the second negative active material comprises carbon selected from the group consisting of carbon black, graphite, activated carbon, and combinations thereof.
12 . The flooded lead-acid battery of claim 11 , wherein carbon black, graphite, and activated carbon are present in a 1:1:4 weight ratio.
13 . The flooded lead-acid rechargeable battery of claim 9 , wherein the second negative active material has a lead to carbon mass ratio of about 30:1.
14 . A negative electrode plate for a flooded lead-acid battery comprising:
an electrode grid defining first and second grid regions;
a first negative active material comprising lead and coating the first grid region; and
a second negative active material comprising carbon and lead, having a lead to carbon mass ratio of about 5:1 to about 82:1, and coating the second grid region.
15 . The negative electrode of claim 14 , wherein the lead to carbon mass ratio of the second negative active material is about 30:1.
16 . The negative electrode of claim 14 , wherein the second grid region is below the first grid region.
17 . The negative electrode of claim 14 , wherein the second negative active material comprises carbon selected from the group consisting of carbon black, graphite, activated carbon, and combinations thereof.
18 . The negative electrode of claim 17 , wherein carbon black, graphite, and activated carbon are present in a 1:1:4 weight ratio.
19 . The negative electrode of claim 17 , wherein carbon black, graphite, and activated carbon are present in a 1:1:1 weight ratio.
20 . The negative electrode of claim 14 , wherein the second grid region comprises between 15% and 50% of the area of the electrode grid.