A modern EV battery pack contains hundreds or thousands of cells, dozens of busbar connections, cooling plates, sensor harnesses, and structural elements — and adhesive tapes appear at nearly every interface. Tapes provide electrical insulation, component fixation, thermal coupling, cushioning, and abrasion protection, often replacing mechanical fasteners or liquid coatings because they are lighter, faster to apply, and easier to automate on assembly lines.
The consequences of a wrong choice are serious. An insulation film that softens below the pack's worst-case temperature, an adhesive that loses peel strength after thermal cycling, or a non-flame-retardant material in a propagation-critical zone can all contribute to short circuits or faster thermal-runaway spread. Tape properties are typically verified by standardized methods — peel adhesion per ASTM D3330, dielectric breakdown testing, and flammability classification — but final material approval always belongs to the cell maker or vehicle OEM. Treat every recommendation in this guide as a starting point, not a substitute for the OEM specification.
Cylindrical and prismatic cells are commonly over-wrapped with thin PET film-based insulation tape — the familiar blue or green wrap on 18650 and 21700 cells. PET (biaxially oriented polyester, also sold as mylar tape) offers a strong balance of dielectric strength, puncture resistance, and cost, with continuous service temperatures typically in the ~120–220°C range depending on grade. For most cell-wrapping and inter-cell barrier duties, flame-retardant PET grades are the workhorse choice.
Where temperatures climb higher — near busbar weld zones, terminal areas, or heater elements — polyimide (Kapton-type) tape takes over, with typical continuous ratings of ~260–300°C and excellent dielectric stability across that range. Polyimide film also resists the brief heat spikes of laser and ultrasonic welding processes used in module assembly. For a deeper look at how polyimide ratings are defined, see our guide to Kapton tape temperature ratings.
Busbars carry high currents between cells and modules, and any exposed conductor near an adjacent potential is an arcing risk. Insulation tapes are wrapped or laminated over busbars, terminal covers, and creepage-distance extensions to maintain electrical clearance in tight pack layouts. Key parameters are dielectric breakdown voltage, film thickness consistency, and conformability around bent copper or aluminum bar.
Flammability is the second gatekeeper. Many pack designs call out materials referencing the UL 94 flammability classification concept — with V-0-type self-extinguishing behavior frequently required for materials inside the pack enclosure. Flame-retardant PET, polyimide, and certain high-temperature tape constructions are formulated to meet these expectations, but the exact classification must be confirmed on the specific product datasheet, at the specific thickness used. Our guide on how to choose high-temperature tape covers the selection logic in more detail.
Heat generated during fast charging and discharge must move from cells into cooling plates or heat sinks. Thermally conductive interface materials — including thermal pads and double-sided heat transfer tapes — fill the microscopic air gaps between cell surfaces and cooling structures, lowering contact resistance. Thermal conductivity varies significantly by grade and filler loading, so compare datasheet values measured by the same test method rather than headline numbers.
Some designs also use fiberglass thermal tape where mechanical reinforcement and heat resistance are needed together, and aluminum foil tape for heat spreading or sealing around thermal barriers. Silicone adhesive systems are common in these zones because they retain adhesion at elevated temperatures and remove cleanly during rework — useful in module repair scenarios.
Pouch and prismatic cells swell and contract through charge cycles, so packs include compression pads between cells to maintain uniform stack pressure. Die-cut PE foam and EVA foam tapes serve as cushioning, gap-filling, and vibration-damping layers, while acrylic foam tape provides high-strength structural bonding for brackets, covers, and trim where long-term holding power matters more than softness.
Wiring harnesses for voltage-sense lines and temperature sensors are bundled and routed with wrapping tapes that resist abrasion and dampen rattle. Adhesive chemistry matters here: acrylic adhesives deliver superior UV and aging resistance for the vehicle's lifetime, while rubber adhesives offer higher initial tack but lower temperature tolerance — the trade-offs are explained in our comparison of acrylic vs rubber adhesive tape. For ESD-sensitive electronics assembly around the BMS, ESD-safe tapes prevent static damage during handling.
When qualifying a tape supplier for battery applications, request: dielectric breakdown data, continuous and peak temperature ratings, peel adhesion per ASTM D3330, flammability classification documentation, and RoHS/REACH compliance statements. Because pack geometries are unique, most battery tapes are supplied as converted parts — precision die-cut rings, busbar covers, cell-end discs, and gap pads rather than plain rolls. Confirm dimensional tolerances and liner formats compatible with your automated placement equipment.
HONGFU manufactures factory-direct tapes used across EV battery assembly — including polyimide tape, flame-retardant PET and insulation tapes, foam compression materials, thermal interface products, and custom die-cut formats — with RoHS/REACH-compliant materials and OEM/ODM support. Send your drawings or target specifications via our inquiry page for samples and engineering feedback. Final qualification should always follow your cell maker's and OEM's test protocols.
Most cylindrical and prismatic cells are wrapped with thin flame-retardant PET film tape, which combines dielectric strength, puncture resistance, and low cost at service temperatures of roughly 120–220°C. Polyimide tape (~260–300°C) is used instead near terminals, weld zones, and other high-heat areas. The exact film, thickness, and adhesive are defined by the cell maker's specification.
Many pack designs require self-extinguishing materials referencing the UL 94 classification concept, often V-0-type behavior, for films and tapes inside the enclosure. Requirements vary by OEM and by location within the pack, so always confirm the flammability classification on the specific product datasheet at the thickness you intend to use.
Choose polyimide when continuous or peak temperatures exceed what PET grades tolerate — typically above the ~120–220°C PET range — such as near busbar welds, terminals, or heating elements. Polyimide maintains dielectric properties up to roughly 260–300°C. For lower-temperature cell wrapping and barrier layers, flame-retardant PET is usually more cost-effective.
Yes. Most EV battery tapes are delivered as converted components — die-cut rings, discs, busbar covers, and gap pads cut to drawing — often on liners compatible with automated placement. Provide a dimensioned drawing or DXF file with tolerance requirements when requesting quotes from a tape converter.
Request datasheets with temperature ratings and dielectric strength, peel adhesion values tested per ASTM D3330, flammability classification evidence, RoHS and REACH compliance statements, and batch traceability. Then run your own validation per the OEM or cell maker's protocol, since supplier data is a starting point rather than final approval.
HONGFU manufactures 59 categories of industrial tape, factory-direct with custom die-cutting.
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