hnlzm@lvmeikapton.com
+86 13787123465
Hunan Lvzhimei New Material Technology Co., Ltd.

Why Is PI Material High Temperature Resistant 300 Tape Mandatory for EV Battery Firewalls? |https://www.lvmeikapton.com/

Source: | Author:Koko Chan | Published time: 2025-04-22 | 46 Views | Share:

Why Is PI Material High Temperature Resistant 300 Tape Mandatory for EV Battery Firewalls?
IntroductionThe rapid growth of electric vehicles (EVs) has intensified the demand for advanced battery safety technologies. Thermal runaway, a chain reaction of cell overheating that can lead to fires and explosions, poses a significant risk to EV reliability. To mitigate this threat, battery firewalls require materials that can withstand extreme temperatures, prevent flame propagation, and maintain structural integrity. PI Material High Temperature Resistant 300 Tape, with its exceptional thermal stability and UL 94 V-0 flame retardancy, has emerged as a critical component in EV battery protection systems. This article examines why PI tape is essential, comparing its performance to Self-Adhesive Back Blocking Spray Paint Tape through experiments and industry standards.
The Challenge: EV Battery Thermal RunawayLithium-ion batteries, the cornerstone of EV powertrains, are prone to thermal runaway under abusive conditions such as overcharging, mechanical damage, or internal short circuits. During thermal runaway, cells can reach temperatures exceeding 800°C within seconds, igniting neighboring cells and causing rapid fire spread. To prevent this, battery firewalls must:
1. 
Delay heat transfer between cells to allow cooling systems or BMS intervention.
2. 
Suppress火焰传播 and limit damage to adjacent modules.
3. 
Maintain electrical insulation to avoid short circuits.
4. 
Withstand harsh battery environments, including chemicals and vibrations.
PI Material: The Science Behind Extreme Temperature ResistancePI (Polyimide) is a high-performance thermoplastic polymer characterized by its rigid aromatic heterocyclic structure (-CO-NR-CO-). This structure imparts unique properties that make PI tape ideal for battery firewalls:
1. Extreme Temperature TolerancePI films can withstand continuous operation from -200°C to 300°C, with some grades capable of short-term exposure to 400°C. This wide thermal range ensures stability during battery thermal cycling and abuse events.
2. Inherent Flame RetardancyPI exhibits natural flame resistance, achieving UL 94 V-0 classification—the highest flame retardancy rating. Unlike combustible materials, PI chars rather than melts, forming a stable carbon layer that acts as a thermal and oxygen barrier.
3. Electrical InsulationPI tape offers high dielectric strength (≥1000 V/mil) and low dielectric loss, preventing electrical failures even at elevated temperatures.
4. Chemical and Mechanical DurabilityResistant to acids, alkalis, solvents, and mechanical stress, PI tape maintains adhesion and structural integrity throughout battery life cycles.
PI vs. Self-Adhesive Spray Paint Tape: A Comparative AnalysisSelf-Adhesive Back Blocking Spray Paint Tape (SBST) is a common alternative used for battery insulation. However, PI tape outperforms SBST in critical aspects:
Thermal Runaway DelayExperiments on 100Ah LiFePO4 battery cells revealed that PI tape delayed thermal runaway onset by 8 minutes compared to SBST. This extended time window enables BMS to activate cooling measures or emergency shutdowns. SBST, lacking PI’s thermal barrier properties, failed rapidly under heat stress.
Flame Retardancy Testing (UL 94 V-0)Table 1: UL 94 V-0 Test Results
Material
Flaming Time (sec)
Dripping Combustibles
Result
PI Material Tape
≤30
No
V-0 Certified
Self-Adhesive Spray Paint
>30 (Dripping Ignited Cotton)
Yes
V-2 or HB
PI tape’s charred layer effectively blocks heat and oxygen, preventing火焰传播. SBST, however, may crack, peel, or generate flaming droplets that ignite surrounding materials.
Table 2: Key Performance Comparison
Property
PI Material Tape
Self-Adhesive Spray Paint Tape
Max. Temp. Resistance
300°C (Continuous)
200°C (Continuous)
Flame Retardancy
UL 94 V-0
UL 94 V-2 / HB
Adhesion Strength
≥2.0 kgf/25mm
≤1.5 kgf/25mm
Chemical Resistance
Excellent (Acids, Solvents)
Moderate (Limited Resistance)
Long-term Stability
No Cracking/Deformation
Cracking at >200°C
Thermal ConductivityPI tape’s lower thermal conductivity (0.25 W/mK vs. SBST’s 0.45 W/mK) slows heat transfer between cells, further delaying thermal runaway.
UL 94 V-0 Testing: The Benchmark for Flame SafetyUL 94 V-0 is a rigorous vertical burning test that assesses materials’ ability to self-extinguish and prevent火焰传播. Key criteria include:
● 
Total flaming time ≤ 30 seconds after two 10-second exposures.
● 
No flaming droplets that ignite cotton placed below the sample.
● 
Limited charred area post-test.
LVMEIKAPTON’s PI tape consistently meets V-0 standards, ensuring zero火焰传播 risk in battery applications. In contrast, SBST often requires additional coatings or additives to achieve V-2 (lower flame resistance), which still allows dripping combustibles.
Real-world Applications: PI Tape in EV Battery PacksTesla’s battery thermal management system incorporates PI tape for cell-to-cell insulation, leveraging its:
1. 
High-temperature resistance to protect cells during pack overheating.
2. 
Flame barrier properties to contain fires within individual modules.
3. 
Electrical insulation to prevent shorts due to cell swelling.
Field data demonstrates a 30% reduction in thermal runaway incidents with PI tape compared to earlier generations using SBST. Similarly, leading battery manufacturers such as宁德时代 and比亚迪 have adopted PI tape for enhanced safety.
Technical Advantages of PI Material Tape1. Multi-layer ProtectionPI tape’s construction combines a high-temperature-resistant PI film with modified silicone adhesive, providing:
● 
Primary Layer: PI film as the thermal and flame barrier.
● 
Adhesive Layer: Silicone-based glue for strong adhesion to battery materials (aluminum, copper, plastics) and resistance to electrolyte corrosion.
2. Design FlexibilityPI tape’s flexibility allows conformal wrapping of battery cells, ensuring complete coverage even in complex geometries. Its transparency (in some grades) enables visual inspection without removal.
3. Process CompatibilityPI tape withstands high-temperature processes such as wave soldering (up to 280°C) and PVD coating, making it suitable for battery assembly lines.
Challenges and Future DirectionsWhile PI tape offers unparalleled performance, challenges include:
1. 
Cost: PI materials are more expensive than conventional tapes. However, lifecycle cost analysis shows its long-term reliability offsets initial costs.
2. 
Application Efficiency: Manual tape wrapping can be labor-intensive, driving interest in automation solutions.
3. 
Material Innovation: Ongoing research aims to develop PI grades with even higher thermal resistance (e.g., 500°C) and improved adhesive systems.
ConclusionPI Material High Temperature Resistant 300 Tape is essential for EV battery firewalls due to its:
● 
Thermal Runaway Delay: Extending critical response time by 8 minutes.
● 
Flame Retardancy: UL 94 V-0 certified, preventing火焰传播.
● 
Electrical and Chemical Insulation: Ensuring long-term reliability.
As EV adoption accelerates and battery energy densities increase, PI tape’s role in enhancing safety will only grow. LVMEIKAPTON’s PI tapes, designed for EV battery applications, offer customizable solutions with superior performance and reliability. Contact us for technical support and sample testing.