Aerogel Thermal Insulation Pads for EV Battery Packs: Everything You Need to Know

What Is an Aerogel Thermal Insulation Pad?

Aerogel is one of the lightest and most thermally insulating solid materials known to science. In its raw form, it's fragile — but when composited with flexible base materials like glass fiber, pre-oxidized fiber (POF), or ceramic fiber, it becomes a highly practical engineering material.

An aerogel battery thermal pad is made by combining nano-aerogel with a flexible substrate, then encapsulating it with polymer films (PET or PI) or flame-retardant coatings through hot-press or coating lamination processes. The result: a thin, lightweight pad that sits between battery cells and does two critical jobs:

• Blocks heat from spreading between cells
• Cushions cells as they expand and contract during charge/discharge cycles

---

Why Does This Matter? The Thermal Runaway Problem

Thermal runaway is one of the most serious failure modes in lithium battery packs. When a single cell overheats — due to overcharge, physical damage, or manufacturing defects — it can trigger a chain reaction that spreads to neighboring cells, potentially causing fire or explosion.

The aerogel pad acts as a thermal firewall between cells. When one cell enters thermal runaway, the pad blocks heat transfer to adjacent cells, interrupting the domino effect before it starts. This is why aerogel pads have become a standard component in EV battery pack design, particularly as pack energy density increases and cell-to-cell spacing decreases.

---

Key Performance Advantages

• Ultra-low thermal conductivity — outperforms conventional foam, mica, and fiberglass insulation
• Lightweight & thin profile — minimal impact on pack weight and volumetric efficiency
• Flame retardant — inherently non-combustible, meets Class A fire protection requirements
• Compressible — accommodates cell swelling (typically 2–5% volume change per cycle)
• Long service life — stable performance across thousands of charge/discharge cycles

---

Three Substrate Options: Which One Is Right for You?

Not all aerogel pads are the same. The base material determines the temperature rating, flexibility, and best-fit application. Here's how the three main options compare:

1. Glass Fiber Aerogel Pad | Max Temperature: 650°C

Glass fiber is one of the most well-studied reinforcement materials for SiO₂ aerogel composites. It provides excellent mechanical support, reduces volume shrinkage after heat treatment, and improves compressive strength.

Manufacturing process: Impregnation with silica sol → gelation → solvent exchange → supercritical drying → silicone frame embedding → film lamination

Key properties:

• Low thermal conductivity
• High hydrophobicity
• Good shock absorption
• Natural fire resistance
• Available in both flexible and rigid forms

Best for: Commercial EVs and electric buses, industrial pipeline insulation, building envelope insulation, high-temperature equipment insulation

---

2. Pre-Oxidized Fiber (POF) Aerogel Pad | Max Temperature: 450°C

Pre-oxidized fiber — the precursor material for carbon fiber production — combines good flexibility with inherent flame resistance. It does not sustain combustion and maintains structural integrity at temperatures up to 450°C.

Manufacturing process: Impregnation with silica sol → gelation → surface modification → supercritical drying → silicone frame embedding or direct flame-retardant adhesive coating

Key properties:

• Low thermal conductivity
• Excellent flexibility
• Strong burn-through resistance
• High tensile strength
• Natural fire resistance

Best for: Passenger EV battery packs (cell-to-cell and module-to-module insulation), 3C electronics thermal management

---

3. Ceramic Fiber Aerogel Pad | Max Temperature: 1050°C

Ceramic fiber brings ultra-high temperature resistance to the aerogel composite system. With low density, excellent fire resistance, and low thermal conductivity, it's the choice for the most demanding thermal protection applications.

Manufacturing process: Impregnation with silica sol → gelation → solvent exchange → supercritical drying → silicone frame embedding → film lamination

Key properties:

• Ultra-high temperature resistance (up to 1050°C)
• Very low thermal conductivity
• Low density

Best for: Premium passenger EVs, high-end battery pack applications requiring maximum thermal runaway protection

---

Other Aerogel Variants

Beyond the three main substrate types, aerogel technology continues to evolve. Other variants include:

• Foam aerogel — enhanced cushioning properties
• Basalt fiber aerogel — natural volcanic fiber base, good cost-performance ratio
• Melamine aerogel — organic aerogel with excellent sound absorption

---

Lamination & Stack Structure Options

Aerogel pads are typically delivered as finished composite assemblies, ready for integration into battery pack production lines. Common stack structures include:

• PET + Silicone Frame + Treatment Agent + Aerogel Pad + PET — Standard encapsulated pad with silicone edge seal
• PET + PPO + Aerogel Pad + PET — Enhanced surface treatment variant
• PET + Aerogel Pad + PET — Basic laminated structure

Double-sided tape application is available for flat and slightly curved surfaces, supporting centered tape bonding on 1–5mm thick sheet products using vacuum hot press equipment.

---

Application Industries

Aerogel thermal pads are used across a wide range of industries where thermal insulation in confined spaces is critical:

• Electric passenger vehicles
• Electric buses (Class A fire protection)
• Stationary energy storage systems (ESS)
• Aerospace & defense electronics
• Home appliances (thermal storage heaters, refrigerators)
• Electronic communication equipment
• Precision instrumentation

---

About Geson Supply

Geson Supply is a professional one-stop supplier of battery pack assembly materials and industrial auxiliary materials, serving small and medium-sized manufacturers worldwide.

We provide tapes & adhesives, insulation & protection materials, thermal management solutions, foam & sealing, structural bonding and labeling materials — all customizable to your pack specifications. Our materials are also widely used in EV electronics, telecom base stations and industrial equipment manufacturing.

Email: kyle@gesonco.com

WhatsApp: +86 188 5766 5584

Website: www.gesonco.com