Dielectric Insulation Tapes for Battery Systems

Electrical isolation is a non-negotiable requirement in high-voltage EV battery modules and packs. Dielectric tapes provide a thin-profile alternative to moulded insulators, liquid coatings, and mechanical spacers — reducing stack height, simplifying assembly, and enabling automated application at production speeds.

Avery Dennison dielectric insulation portfolio addresses two distinct but complementary application scenarios.

• The ES 1421 is designed for flat and rigid substrate surfaces including prismatic cell wraps, busbars, cooling plates, and cell connection systems. Its 85 µm total caliper delivers a dielectric breakdown voltage exceeding 8 kV while adding minimal thickness to the module stack. The advanced acrylic adhesive provides high shear performance (2.0–4.0 MPa lap shear) and proven compatibility with multiple structural adhesives and thermal interface materials, making it suitable for laminated multi-layer assemblies where the dielectric tape must maintain position under secondary bonding loads. The adhesive’s shear adhesion failure temperature (SAFT) exceeds 200 °C, providing a margin above typical battery operating conditions.
• The FT 0031, part of the Volt Tough™ EV Battery Portfolio, addresses geometries where standard tapes fail. Its proprietary stretchable polyolefin carrier achieves over 300% elongation, allowing the tape to survive aggressive metal forming operations while maintaining a dielectric strength of >10kV (AC). This enables a manufacturing sequence change: the tape can be applied to flat stock before forming, maintaining dielectric integrity through bending, drawing, and stamping processes. For battery pack components with complex or unique geometries — formed aluminium housings, bent busbars, contoured cooling plates — this eliminates the need for post-forming insulation application in tight spaces.

Both variants are single-coated, optimized for high-speed die-cutting and automated tape-laying. The ES 1421 features high initial tack for reduced dwell time requirements, while the FT 0031 uses a pure acrylic adhesive formulated for strong adhesion to metallic battery pack components.