Project Background
A battery module manufacturer in South Korea was developing a 600V lithium-ion battery pack for commercial electric vehicles.
The battery pack architecture included:
Cylindrical lithium-ion cells
Aluminum cooling plates
Nickel-plated copper busbars
Integrated BMS monitoring boards
The system needed to meet validation standards aligned with:
IEC 62660
Underwriters Laboratories safety evaluation requirements
Engineering Challenge: Insulation Stability Under Thermal Cycling
During prototype validation, engineers observed:
PET insulation tape shrinkage at 140–160°C
Adhesive softening near high-current busbars
Reduced dielectric margin after 150 thermal cycles
Risk of metal edge exposure under vibration stress
While the module passed initial assembly checks, long-term reliability was uncertain.
A structural redesign was not possible due to production schedule pressure.
Root Cause Analysis
Thermal imaging showed localized hot spots at:
Busbar junction areas
High-current weld points
Cooling plate edges
The previously used polyester insulation tape had:
Limited continuous temperature resistance
Lower dielectric strength under aging
Reduced dimensional stability
The insulation material needed upgrading without increasing thickness.
Recommended Solution: High-Temperature Kapton (Polyimide) Tape
We supplied high-performance Kapton polyimide tape with silicone adhesive, featuring:
Continuous temperature resistance: 200°C
Short-term peak resistance: 300°C
Dielectric strength: >7kV
Thickness: 0.05mm
Excellent dimensional stability
High flame resistance characteristics
The thin profile maintained module compactness while increasing safety margin.
Application Areas Within the Battery Pack
Kapton tape was applied to:
Busbar edge wrapping
Cell terminal isolation
Cooling plate contact interfaces
BMS wiring harness crossover points
High-voltage spacing barriers
Special attention was given to edge tension control and compression zones.
Validation Testing Procedure
After integration, the module underwent:
200-cycle thermal aging test (−20°C to 150°C)
2,500V DC dielectric withstand test
Automotive vibration profile testing
Insulation resistance measurement (>100 MΩ requirement)
Measured Performance Results
| Test Parameter | Previous PET Tape | Kapton Tape |
|---|---|---|
| Thermal deformation | Visible shrinkage | None observed |
| Adhesion retention | Degraded | Stable |
| Dielectric margin | Borderline | +25% safety margin |
| Vibration integrity | Minor lifting | Stable |
The module successfully passed internal safety validation without structural modification.
Why Kapton Tape Is Suitable for EV Battery Insulation
Polyimide (Kapton) film provides:
Exceptional thermal endurance
High dielectric strength at thin gauge
Chemical resistance to electrolyte vapor
Low outgassing
Long-term mechanical stability
Compared to polyester tapes, Kapton maintains insulation integrity under repeated thermal and mechanical stress.
Important Engineering Limitation
Kapton tape is intended for:
Supplemental insulation
Edge protection
High-temperature barrier zones
It does not replace:
Primary cell separators
Certified structural insulation sheets
Fire-rated battery barriers
All insulation improvements must be validated under full battery safety testing protocols.
This clarification strengthens compliance credibility and aligns with E-E-A-T principles.
Compliance Documentation Provided
For this project, we supplied:
Dielectric strength report
Thermal aging test data
Adhesion retention test results
RoHS compliance documentation
Technical datasheets
Our technical team has over 10 years of experience supporting EV battery insulation and power electronics applications.
FAQ
Is Kapton tape suitable for 800V battery systems?
Yes, provided voltage spacing and dielectric requirements are properly engineered and validated.
Can Kapton tape withstand battery thermal runaway?
Kapton has excellent heat resistance, but it is not a substitute for certified fire protection materials.
What thickness is recommended for battery modules?
Typically 0.05–0.1mm depending on voltage rating and spacing design.
Request Technical Support
Looking for a reliable Kapton tape manufacturer for EV battery insulation applications?
We provide:
Custom widths
Die-cut insulation parts
High-voltage grade polyimide tape
Engineering documentation support
Fast global sampling
Contact us to discuss your battery module insulation requirements.