A pouch cell is a type of battery cell that uses a flexible, plastic laminated aluminum foil packaging rather than rigid metal cans used for cylindrical or prismatic cells. The internal layers of the battery (anode, separator, cathode) are stacked or wound and then enclosed in this pouch, which is vacuum sealed around the edges after electrolyte filling. The result is a slim, lightweight cell whose shape can be somewhat customized to the space available Pouch cells have a high packaging efficiency (there’s no heavy casing, so more of the battery’s volume is active material). However, they don’t have the structural support of a hard case, so they rely on the battery pack’s enclosure to apply some pressure and maintain shape. They can swell a bit over time due to gas generation during cycling.
NOVONIX frequently works with pouch cells, including commercial cells and those they build on their pilot line. They analyze pouch cell performance and are attentive to issues like swelling: for instance, they measure the amount of gas generated during formation and can analyze the gas composition. NOVONIX also tests how pouch cells behave under pressure, as applying modest pressure can improve performance by keeping layers in good contact. When developing new materials, NOVONIX adjusts the number of layers for stacked cells, or winding dimensions for wound cells, to achieve the target capacity desired by their customers. Analysis of pouch cells by NOVONIX allows them to troubleshoot any unique challenges that arise with the pouch format.
