How Thermal Shrinkage Concerns Are Influencing Battery Pack Cushion Material Selection

As EV and Energy Storage System (ESS) projects continue to expand in the U.S. market, battery pack protection materials are being evaluated beyond basic cushioning performance. Engineers are increasingly focusing on dimensional stability, compression recovery behavior, and long-term aging performance under real operating conditions.

For Battery Pack Cushioning applications, materials are expected to provide more than impact absorption. They must also maintain structural support during transportation, assembly, and long-term operation.

Why Thermal Shrinkage Is Becoming a Key Consideration

Battery systems often operate under changing temperature conditions.

Typical EV scenarios

• Heat accumulation during fast charging
• High-temperature parking environments
• Temperature rise inside enclosed battery structures

Typical ESS scenarios

• Outdoor container energy storage systems
• Long-duration operation
• Regional temperature fluctuations

When cushioning materials experience shrinkage or deformation under heat exposure, several issues may occur:

• Changes in cell spacing
• Reduced internal support
• Battery movement during transportation
• Reduced cushioning performance after long-term compression

As a result, thermal dimensional stability is becoming an important factor in Battery Protection Material selection.

How EVA Foam Performs Under Thermal Conditions

Based on current material data, Black EVA Foam shows defined performance boundaries:

Key specifications

• Softening begins at 65°C
• Shrinkage begins at 90°C
• Aging may begin after approximately 3 years above 40°C
• Compression set at 85°C: 48–51%
• Compression set at room temperature can be as low as 11%

These figures indicate that EVA Foam is suitable for cushioning, vibration control, and spacing applications rather than continuous high-temperature insulation.

For Battery Accessories EVA Foam Pad applications, engineers typically evaluate:

• Operating temperature
• Compression load
• Cell arrangement structure
• Product lifecycle requirements

How to Select Battery Pack Cushion Materials

Evaluate compression recovery

Compression Set helps assess how well a material maintains support after long-term loading.

Lower compression set values generally indicate more stable structural performance.

Consider temperature limits

Thermal boundaries should align with actual operating conditions.

Material thickness and design structure should also be reviewed near softening or shrinkage temperatures.

Match hardness to support requirements

Black EVA Foam supports Shore C hardness from 25–80.

Lower hardness:

Suitable for impact absorption

Higher hardness:

Suitable for structural support and positioning

Industry Insight: Material Selection Is Moving Toward Condition-Based Design

In the U.S. battery industry, growing attention to transportation safety and system reliability is changing material selection strategies.

For Battery Module Cushioning applications, buyers are increasingly considering:

• Thermal adaptability
• Long-term compression stability
• Structural compatibility
• Internal battery protection requirements

The focus is gradually shifting from cushioning alone toward application-specific material selection.