Low Surface Energy (LSE) Challenges
EV battery packs utilize materials like polypropylene (PP) and polyethylene (PE) for cell separators and module casings. These are Low Surface Energy plastics. Standard adhesives fail to wet out these surfaces, leading to immediate or latent delamination. Specialized LSE-modified acrylic adhesives are required for reliable bonding.
Electrolyte Resistance
In the event of a cell leak, the adhesive tape must withstand exposure to harsh electrolytes (often containing lithium salts and organic solvents). Standard adhesives will dissolve or swell, contaminating the cell chemistry and causing short circuits. Inert polyimide or chemical-resistant PP tapes are mandatory for internal cell wrapping.
Thermal Runaway Mitigation
Tapes used in EV packs must do more than bond; they must act as fire barriers. Standard tapes burn, adding fuel to a thermal runaway event. Flame-retardant (FR) mica tapes or ceramic-coated tissues are essential to prevent fire propagation between cells.