BARRIER LAYER COATINGS FOR BATTERY POUCH CELL SEAL

A prismatic battery cell and a method of making such a cell. The cell includes one or more anode regions, one or more cathode regions, an electrolyte region to facilitate ion flow between the anode and cathode regions, electrically-conductive tabs attached to the corresponding anode and cathode regions, and a pouch-like containment formed around the regions. The containment is made up of a pair of facing substantially planar surfaces sealingly joined to one another. A barrier layer coating is made up of at least one low-permeability material and is placed over at least a portion of the cell edge that is defined by the joined surfaces such that the barrier layer coating blocks ambient gases or vapors from passing through the relatively gas-permeable heat seal region that is used to join the pouch surfaces. The barrier layer coating may also include one or more hydrophobic surface treatments or enhancements, including in one form an additional layer of surface treatments to funtionalize the surface and in another form by surface roughening.