GRAPHENE-BASED COATING ON LEAD GRID FOR LEAD-ACID BATTERIES
A surface coating for application to the surface of lead-grids for lead-acid batteries includes a resin and a carbon material of graphene, graphene nanoplatelets, or a combination thereof, wherein the surface coating is configured to be applied to either electrode of the lead-acid battery. The surface coating providing both a protective coating to prevent corrosion of either or both of the positive and/or negative lead grids and a flexible buffer coating to reduce delamination at the interface of either or both of the positive and/or negative lead grids and the active paste.
1 . A surface coating for the surface of lead-grids for lead-acid batteries wherein the coating comprises at least one resin and a carbon material selected from the group consisting of: graphene and graphene nanoplatelets.
wherein the surface coating is configured to be applied to either electrode of the lead-acid battery.
2 . The surface coating as claimed in claim 1 wherein, in addition, there is also present a functional filler.
3 . The surface coating as claimed in claim 1 wherein the carbon materials are single-layer graphene, multiple-layered graphene, graphene nanoplatelets, with a thickness from 0.3 nm to 100 nm and a diameter from 0.1 microns to 100 microns.
4 . The surface coating as claimed in claim 3 wherein the carbon materials have a thickness from 1 nm to 30 nm and a diameter from 1 to 10 microns.
5 . The surface coating as claimed in claim 1 wherein the lead-grid is made of lead or lead-based alloys containing lead and one or more alloy elements selected from the group consisting of calcium, antimony, tin, silver, and selenium.
6 . The surface coating as claimed in claim 1 wherein the lead-grid is made of lead-carbon composite comprised of lead or lead-based alloys with one or more carbonaceous reinforcement materials selected from the group consisting of carbon black, graphite, carbon fibers, carbon nanotubes, graphene, or graphene nanoplatelets.
7 . The surface coating as claimed in claim 1 wherein the resin is one or more polymers selected from the group consisting of polycarbonates, polysulfones, polyphenylene sulfide (PPS), fluoropolymers, phenolic resins, epoxies, urethanes, acrylonitrile butadiene styrene (ABS), polystyrene, polyolefins, and copolymers of polymers set forth just above.
8 . The surface coating as claimed in claim 1 wherein one or mere functional additives are selected from the group consisting of carbon blacks, graphite, carbon fibers, fullerenes, carbon onions, carbon flowers, carbon nanofibers, carbon nanocaps, vapor grown carbon fibers or carbon nanotubes.
9 . The surface coating as claimed in claim 1 wherein one or more functional additives are selected from the group consisting of metallic particles, fibers, nanotubes, and flakes.
10 . The surface coating as claimed in claim 1 wherein one or more functional additives are selected from the group consisting of ceramic particles, fibers, nanotubes, and flakes.
11 . The surface coating as claimed in claim 1 wherein said composition contains 1-50 wt % of carbon materials based on the weight of the total composition.
12 . The surface coating on lead-grids for lead-acid batteries as claimed in claim 1 wherein the coating has a thickness in the range of 1 to 1000 microns. The surface coating on lead-grids for lead-acid batteries as claimed in claim 15 wherein the coating has a thickness in the range of 1 to 50 microns.
13 . A method of coating lead-grid with a composition as claimed in claim 1 wherein a slurry or ink of the composition is applied by a method selected from the group consisting of dip coating, spray coating, roller coating, printing, or brush coating.
14 . A method of coating lead-grid with a composition as claimed in claim 1 wherein said composition is applied to said lead-grid wherein the composition is prepared by dissolving a resin in a solvent and mixing the carbon material and functional additives into the resin solution by a method selected from the group consisting of mechanical stirring, shearing, or milling.
15 . The method as claimed in claim 14 wherein the solvent is selected from the group consisting of cyclopentanone (cyclic ketone), propiophenone (aryl ketone), anisole, tetrahydrofuran (THF), N-Methyl-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), alcohols, ketones, and water.