Design to Control a Thermal Runaway in Battery Electric Vehicles (BEVs)

Abstract: The rapid electrification of vehicles has neccessitated advancements in battery technology, impacting various components within the car battery pack. This project focuses on the development of thermal barriers, which serve as crucial components that prevent potential fires from thermal runaway incidents in the battery pack from reaching the vehicle's interior compartment. Currently, thermal barriers are predominantly composed of mica. The objective of this project is to identify a more sustainable alternative material to mica that possesses similar properties while considering economic, social, and environmental factors.  Following the product development process, a comprehensive background study and benchmark analysis were conducted. Subsequently, the specific requirements for the new material were defined, and potential suppliers providing alternative materials were identified. Torch tests and dielectric strength tests were performed to assess thermal conductivity, fire resistance, and dielectric properties, which were deemed critical attributes. The test results unveiled a novel material comprised of a combination of two distinct materials from different suppliers. One material was a composite consisting of glass fiber and carbon, exhibiting exceptional thermal properties. The other material was an electrical-grade paper boasting excellent electrical properties. When combined, these materials formed a composite that paralleled the properties of mica. The composite material had a total thickness of 2 mm, slightly thicker than the current implementation of mica. To explore the feasibility of a thinner alternative, an estimation was conducted, suggesting that a thinner sheet of the composite material could be possible. In conclusion, this study demonstrates the feasibility of replacing mica with an alternative material. Further testing and investigation are required to determine the optimal implementation and minimum thickness of the new material. However, based on the successful test results and similarity in properties, it can be affirmed that the new material has the potential to replace mica as a sustainable thermal barrier in the battery pack.