Battery Tabs and Method of Making the Same
A terminal for a Li-ion battery cell utilizes a bimetallic strip formed from the materials used as the Li-ion cell current collectors, such as copper and aluminum. The bimetallic strip is to be used as, at least one, of the Li-ion pouch cell terminals. At least one portion of the bimetallic strip has one of the metallic components removed by such means as chemical or electrochemical etching, mechanical milling, skiving, or grinding, the remaining component being connected to the collector and the other end of the strip serving as the terminal.
1 . In a battery pack having a plurality of cells to be connected, each cell including a pair of discrete internal current collectors of dissimilar metals, the improvement comprising at least one terminal in each cell comprising a bimetallic strip formed with a layer of each metal of said dissimilar metals, each bimetallic strip having one of said layers removed at a first end thereof, said first end being electrically connected to one of said pair of discrete current collectors having the same metal as said first end, said bimetallic strip extending from said cell with at least said other layer exposed to form a battery terminal for electrical connection of said battery cell; and, at least one other terminal formed of at least the same metal as said other discrete internal current collector of said pair of discrete internal current collectors and connected thereto at a first end of said at least one other terminal, with a second end of said at least one other terminal extending from said cell for electrical connection of said battery cell.
2 . The improvement as defined in claim 1 wherein said dissimilar metals are copper and aluminum.
3 . The improvement as defined in claim 2 wherein said bimetallic strip is a strip of clad aluminum and copper.
4 . The improvement as defined in claim 2 wherein said bimetallic strip is a strip of roll bonded aluminum and copper.
5 . The improvement as defined in claim 2 wherein said bimetallic strip is a strip of plated aluminum and copper.
6 . The improvement as defined in claim 2 wherein sad bimetallic strip is a strip of diffusion bond aluminum and copper.
7 . The improvement as defined in claim 2 wherein at least one other terminal is a strip of copper.
8 . The improvement as defined in claim 7 wherein said at least one other terminal is connected to a copper side of said at least one terminal.
9 . The improvement as defined in claim 8 wherein said at least one other terminal is connected to said at least one terminal at an ultrasonic weld joint.
10 . The improvement as defined in claim 8 wherein said at least one other terminal is connected to said at least one terminal at a laser weld joint.
11 . The improvement as defined in claim 8 wherein said at least one other terminal is connected to said at least one terminal at a resistance weld joint.
12 . The improvement as defined in claim 1 wherein said at least one other terminal is connected to said at least one terminal without any secondary phases there between.
13 . The improvement as defined in claim 1 wherein said plurality of cells are Lithium ion cells.