The importance of insulting materials in battery system design

Key Takeaways:

• Electrical Isolation: Insulating materials prevent short circuits by electrically separating components within the battery system.
• Thermal Management: Effective thermal insulation ensures heat dissipation, maintaining optimal operating temperatures and preventing overheating.
• Vibration Damping: Insulators absorb vibrations and impacts, enhancing the durability and reliability of the battery system.
• Compliance with Standards: Adherence to industry standards, such as UL 94, ensures the safety and market readiness of insulating materials.

What are insulating materials in battery systems?

Insulators are mainly used to separate electrical components within a battery system. To perform this role effectively, the insulating material must have high electrical resistance, plus it must have high strength. The gaps also need plugging to avoid empty spaces where dust and other substances can gather, which could affect the battery’s operation and safety.

Proper insulation prevents internal short circuits, which could otherwise lead to catastrophic failures such as thermal runaway or fire hazards. The insulating materials must also maintain their performance over the battery’s full lifecycle, as changes in environmental conditions (e.g., temperature fluctuations) could otherwise compromise the system’s integrity.

Insulators also act as dampers, meaning that they suppress vibrations and impacts, making the battery system more robust and able to withstand the rigours of use. Material must also have some flexibility – Young’s Modulus tells designers which materials are suitable. Protection from impact and vibrations is particularly important with e-bike batteries, which can undergo significant impact at times.

Vibration damping is especially critical in high-energy applications like electric vehicles and e-bikes, where constant movement and road impacts expose the battery system to substantial mechanical stress. Over time, excessive vibrations can cause the battery cells or components to degrade, reducing overall system performance.

The insulator’s flexibility ensures that the battery system can absorb and dissipate impacts without damaging sensitive components or reducing energy storage capacity.

Thermal insulation for batteries

The insulation in a battery system should also act as a thermal conductor, allowing heat to dissipate from cells and FETS on BMS. Silicone pads are highly effective at this, thanks to their thermal properties.

Efficient thermal management is crucial for high-performance battery systems to maintain consistent efficiency, safety, and longevity. Poor thermal management can lead to overheating, which in turn shortens battery life, reduces efficiency, and could trigger thermal runaway under extreme conditions.

It must also be remembered that critical insulators must meet certain guidelines in order to be sold in specific markets. For example, in the US, there are specific requirements regarding flammability, with critical insulators required to be rated or tested according to UL 94.

Adhering to international standards for flammability and thermal resistance ensures that the battery system is both safe and market-ready. Failure to comply with these standards can prevent products from being certified for sale in certain regions and may expose manufacturers to legal and reputational risks.

Compliance with standards such as UL 94 is particularly important for applications in sectors like automotive and aerospace, where safety is paramount and product recalls are costly and detrimental to brand reputation.

Overall, insulating material is very important within a battery system and can’t be overlooked during the design process. At EMBS, our designers understand the importance of insulation and can ensure the correct insulation is used to meet the requirements of any target market.

By selecting the right insulating material based on the specific application, environmental factors, and safety standards, the overall efficiency and longevity of the battery system are maximised.

Read also: Are Electric Bike Batteries Safe?

FAQ

What are insulating materials in battery systems?

Insulating materials are components used to electrically separate various parts within a battery system. They must possess high electrical resistance and mechanical strength to prevent short circuits and ensure the safety and efficiency of the battery.

Why is thermal insulation important in battery systems?

Thermal insulation helps dissipate heat generated during battery operation, preventing overheating and potential thermal runaway. Materials like silicone pads are effective in transferring heat from cells and Battery Management System (BMS) components.

What role do insulating materials play in vibration damping?

Insulating materials act as dampers, suppressing vibrations and impacts. This function enhances the battery system’s robustness, allowing it to withstand the rigors of use, which is particularly crucial for applications like e-bike batteries that may experience significant impacts.

Are there specific standards for insulating materials?

Yes, certain markets have specific requirements for insulating materials. For instance, in the U.S., insulators must meet flammability standards and be rated or tested according to UL 94 to ensure safety and compliance.

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Sources

Quan, T., Xia, Q., Wei, X., & Zhu, Y. (2024). Recent development of thermal insulating materials for Li-ion batteries. Energies, 17(17), 4412.

Sun, X., Dong, Y., Sun, P., & Zheng, B. (2024). Effects of thermal insulation layer material on thermal runaway of energy storage lithium battery pack. Journal of Energy Storage, 76, 109812.

Ouyang, D., He, Y., Weng, J., Liu, J., Chen, M., & Wang, J. (2019). Influence of low temperature conditions on lithium-ion batteries and the application of an insulation material. RSC advances, 9(16), 9053-9066.

Bai, Q., Li, K., Zan, J., Liu, J., Ou, J., & Liu, J. (2023). Influence of insulation material thickness on spread of thermal runaway in battery packs. Processes, 11(5), 1321.