Light-weight bipolar valve regulated lead acid batteries and methods therefor
Light-weight VRLA batteries comprise a thin lead substrate that is supported by non-conductive, preferably plastic frames that provide structural stability to accommodate stress and strain in the bipole assembly. In particularly preferred batteries, the plastic frames are laser welded together and phantom grids and electrode materials are coupled to the respective sides of the lead substrate. Where the phantom grid is an ultra-thin lead grid, the lead grid is preferably configured to provide a corrosion reserve of less than 10 charge-discharge cycles and the bipole assembly is charged in an in-tank formation process. Where the phantom grid is a non-conductive grid, the lead grid is preferably a plastic grid and the bipole assembly is charged in an in-container formation process. Consequently, weight, volume, and production costs are significantly reduced while specific energy is substantially increased.
1. A bipolar electrode assembly, comprising:
a first non-conductive frame defining a first window,
wherein the first frame is coupled to a second nonconductive frame defining a second window, being connected together by a continuous laser weld to create a seal therebetween;
a lead foil disposed between and coupled to the first and second frames such that opposite first and second sides of the lead foil are accessible through the first and second windows, respectively;
wherein at least one of the first and second non-conductive frames further comprises an enhanced adhesive comprising a viscosity modifier and a coupling agent, wherein the enhanced adhesive is positioned between the lead foil and the at least one of the first and second non-conductive frames;
a first phantom grid coupled to a positive electrode material, wherein the first grid and the positive electrode material are positioned in the first window and are conductively coupled to the first side of the lead foil; and
a second phantom grid coupled to a negative electrode material, wherein the second grid and the negative electrode material are positioned in the second window and are conductively coupled to the second side of the lead foil.
2. The assembly of claim 1 wherein the viscosity modifier is a fumed silica powder, and wherein the coupling agent is a silane.
3. The assembly of claim 1 wherein the lead foil is a lead tin alloy and has a thickness of less than 0.2 mm.
4. The assembly of claim 1 wherein at least one of the first and second phantom grids are manufactured from a nonconductive material.
5. The assembly of claim 1 wherein at least one of the first and second phantom grids are manufactured from lead or a lead alloy and are configured to provide a corrosion reserve of less than 10 charge-discharge cycles.
6. The assembly of claim 1 wherein the positive electrode material is positive active material, and wherein the negative electrode material is negative active material.
7. The assembly of claim 1 wherein the positive and negative electrode materials are lead oxide paste.
8. The assembly of claim 1 conductively coupled to a negative end pole assembly, a positive end pole assembly, a separator, and at least one additional assembly according to claim 1 to thereby form a bipolar battery assembly.
9. The assembly of claim 8 wherein the bipolar battery assembly is encapsulated in a thermoplastic polymer.