Publish Time: 2026-09-10 Origin: Site
Choosing a battery insulation material from thermal conductivity alone can create a pack that performs well on a datasheet but fails to manage compression, electrical isolation or thermal runaway.
For thin cell-to-cell thermal insulation, aerogel is one of the strongest options available, but there is no single best material for every location inside an EV battery pack. Mica, silicone foam and aerogel perform different functions, and advanced packs may use them together.
Using a bulky insulation layer between cells can consume valuable battery-pack volume and reduce the space available for active material.
Aerogel is particularly attractive where engineers need high thermal resistance in a thin and lightweight cell-to-cell barrier. Commercial automotive aerogel barriers are designed for pouch and prismatic battery architectures and can combine thermal and mechanical functions.[1]
Material |
Main Strength |
Typical EV Battery Role |
|---|---|---|
Aerogel |
High thermal resistance at low thickness |
Cell-to-cell thermal barrier |
Mica |
Electrical insulation and high-temperature barrier |
Modules, busbars, pack barriers |
Silicone Foam |
Compression, cushioning and sealing |
Cell pads, enclosure sealing and gap management |
Replacing mica with aerogel everywhere can weaken electrical or structural insulation functions, while using mica everywhere may not deliver the desired cell-to-cell thermal performance per unit thickness.
Use aerogel when thin thermal resistance is the priority and mica when electrical insulation, dimensional stability and high-temperature barrier performance dominate. In many EV packs, the engineering answer is not aerogel versus mica—it is deciding where each material belongs.
Confusing thermal barriers with compression pads can cause poor cell support or inadequate thermal protection.
Aerogel is generally selected primarily for thermal-barrier performance, while silicone foam is widely used for compression, cushioning, gap management and sealing. Specialized products can combine multiple functions, so the final comparison must use actual material data and battery conditions.
Thermal runaway protection also requires system-level validation. UL 2596 material screening considers severe thermal and mechanical effects associated with battery thermal runaway rather than relying on a normal temperature rating alone.[2]
Not Sure Whether to Use Aerogel, Mica or Silicone Foam?
Send Fuqiang your EV battery drawing, cell format, available gap, temperature requirements and assembly conditions. We can help review where aerogel, mica and silicone foam should be positioned and prepare custom samples for evaluation.
There is no universal best material. For EV battery cell-to-cell barriers where low thickness and high thermal resistance are critical, aerogel is a strong candidate.
Aerogel can provide high thermal resistance at much lower thickness in specialized applications, but cost, mechanical construction and application requirements are different.
Aerogel thermal barriers are increasingly used between pouch and prismatic cells, but the correct material and thickness must be validated against the specific cell and pack design.
Mica does not stop the electrochemical thermal runaway process inside a failing cell. It can serve as a high-temperature and electrical barrier that helps manage heat and flame exposure in the surrounding system.
Yes. A battery pack can use aerogel for cell-to-cell thermal resistance and mica in locations requiring additional electrical isolation or high-temperature barrier performance.
800V battery packs can use multiple insulation technologies, including aerogel, mica, films, foams and engineered polymers. Material selection depends on both thermal and high-voltage electrical requirements.
15-Year Automotive Wire Harness Engineering Perspective
After 15 years working around automotive electrical systems and EV components, I rarely recommend asking for the “best insulation material” without first defining its location. Aerogel, mica and silicone foam solve different problems inside the battery pack. Good EV design puts each material where its properties create the most value.