Welding Lithium Battery Cells
Lithium Batteries are quickly becoming the norm in batteries. Lithium batteries are so named due to the lithium anode used in the construction of these cells. Lithium batteries stand apart from other cells in a couple of different ways. First, Lithium cells have a high discharge density and have the ability to charge and discharge very efficiently. Lithium Cells are commonly used in Portable Electronics, Radio Controlled hobbies, and Electric Vehicles. There are 4 main types of Lithium Battery Cells. Prismatic, Pouch, Cylindrical, and Button Cells. Each of these cells are compatible with welding. Below we will discuss each of them and welding applications of each of these cells.
Prismatic Lithium Cells
Prismatic Lithium Cells are one of the more common types of Lithium Battery cells. They are commonly used in cell phones, tablets, cameras, and in electric vehicles. A prismatic cell consists of the anode, cathode, separator, and electrolyte wrapped in a metal container. Each prismatic cell is custom made for each application, and there is hardly any crossover from cell to cell. Prismatic Cells are generally safer than most lithium cells, and provide an added layer of protection, as they are sealed in a metal case.
Welding Prismatic Cells
There are a variety of applications for welding prismatic Cells.
- Weld tabs and multiple layers of current collectors
- Welding multiple layers of foils
- Weld Tabs Together to create battery assemblies
- encase and seal cases and covers.
- Cell to Cell Joining
- Module to Module Joining
Lithium Pouch Cells
Lithium pouch cells consist of stacked layers of anodes, separators, and cathodes sandwiched in between layers of the laminated film. These pouch cells can be created in custom sizes and shapes. Each Pouch cell provides 3-4 volts. Pouch cells are then connected in series and parallel to acquire the desired voltage, and capacity. In a pouch cell configuration, the S in the number specifies how many are in series, and the P specifies how many pack assemblies. For example, if you have a 4s4p pack, this would be a total of 16 cells. 4 packs of 4 cells each.
Welding Lithium Pouch Cells
Lithium pouch cells can be welded in a number of ways, both in the creation and in the assembly process.
- Hermetic sealing of custom Pouches
- Welding Layers to Lead tabs
- Creating Lead tabs
- Cell to Cell Connections
- Module to module Connections
Lithium Cylindrical Cells
Cylindrical Cells are becoming more and more common as various industries require the high discharge rates that Lithium Cells provide. Cylindrical cells consist of anode, cathode, and separator rolled up and sealed in a battery canister with an electrolyte. These cylindrical cells come in various sizes. The number system used to classify the battery is also the size of the cell. For example, a 18650 cell is 18 mm x 65 mm. A 26650 cell is 26mm x 65 mm. Cylindrical cells do have a higher safety concern in that they generally have a positive and negative terminal on the same side. The side of the can generally is the negative terminal and the raised portion the positive, these can easily be shorted if the wrapping is damaged or removed.
Welding Cylindrical Lithium Cells
Here at Sunstone Welders, we understand that the future of batteries is in both lithium cells, and high voltage, high capacity battery packs. We Believe that the best way to improve battery packs is to use Cooper battery tabs instead of traditional nickel. Copper battery tabs give both better battery performance, but as well better battery lifespan. Sunstone Welders pioneered welding copper battery tabs with the Sunstone Omega PA250i Welding system. This system provides an economical, robust, system for welding Lithium Cylindrical cells.
Customer Highlight Using Copper Tabs
Lithium Button or Coin Cells
The last lithium cell type is the Lithium Button or coin Cells. Used in small electronics, Watches, Calculators, medical devices and anywhere a small battery is required. Button Cells come in both an alkaline and lithium type battery.
Welding Lithium Button or Coin Cells
Coin or Button Lithium Cells Can be welded using traditional battery welding technology. A tab is used to either join several cells together or to extend the connection of a button or coin cell. A magnet wire can be attached to the cell to create an electrical connection, or for monitoring.