In the second step of battery manufacturing, “cell assembly,” the shape of batteries is decided. The orders and methods employed for manufacturing depend on the shape of the battery. How are pouch batteries, the light and highly energy-dense ones among different battery types, assembled? Let’s find out with an infographic.
Making a Pouch Case
To make a pouch battery, we need a pouch case that will be containing battery ingredients consisting of the cathode, anode, separator, and electrolyte. First, a 7-layer pouch film is put on a mold and pressed in a machine. An electrode pocket in which battery ingredients are placed and an air pocket in which gas can be stored are formed in this step.
Making a Bi-cell
For producing battery ingredients, first we need bi-cells. The basic unit of a battery, multiple electrodes, and separators are combined in a bi-cell. It has a laminated structure with the same electrodes at the sides like in cathode / separator/ anode / separator/ cathode or anode/ separator/ cathode / separator/ anode.
Lamination & Stacking
“Lamination and stacking” is a method developed single-handedly by LG Energy Solution and is used in dealing with bi-cells. This method enables highly efficient use of space inside the case by stacking up battery ingredients tightly while improving energy density and safety.
First comes lamination, the process of attaching half-cells that consist only of separators and anodes to finished bi-cells. Then comes stacking in which cathode and anode are stacked up on each side of the separator. The two processes are repeated, resulting in battery ingredients with the layers of electrodes and separators.
When battery ingredients made through lamination and stacking methods are put into the electrode pocket, electrolyte is injected into the air pocket reaching pores in the electrode pocket. This process creates gas in the air pocket, which is removed later through degassing.
We have caught a glimpse of the assembly process of pouch batteries!
LG Energy Solution is enhancing productivity and quality of pouch batteries with the differentiated lamination and stacking method.