The battery assembly process brings together electrodes, separators, and electrolytes. And it requires different manufacturing orders and techniques by the battery shape. Let’s start with how the pouch battery is assembled!
Relatively Simple Assembly Process
To make a pouch battery, we need a pouch case and battery ingredients consisting of the cathode, anode, separator, and electrolyte. Unlike cylindrical batteries, pouch batteries are simple to assemble because they do not need cans and parts.
7-layer Pouch Case
To begin with, a 7-layer pouch film is put on a mold and pressed flat in a machine to make a pouch case. In this step, an electrode pocket in which battery ingredients will be placed as well as an air pocket in which electrolyte will be injected and gas will be stored are formed.
Electrolyte Injection and Degassing
Then, battery ingredients are put into the electrode pocket and electrolyte is injected into the air pocket to reach even pores in the electrode pocket. Pouch batteries are pressed with a roller to inject the electrolyte before being sealed, unlike cylindrical batteries. The gas created in doing so is gathered in the air pocket.
Once pouch batteries are sealed after the electrolyte injection, the next step is degassing which is to remove gas by cutting the air pockets in order to reduce volume and increase energy density. When degassing is done, the assembly of a pouch battery is finished.
After a pouch case is made in the assembly process, battery ingredients need to be put in the case. Among many methods of doing so, we will take a look at lamination and stacking next time!