Why Pressure Sensors Outperform Gas and Temperature Sensors in Thermal Runaway Detection
Battery management systems (BMS) increasingly opt for internal pressure sensors over traditional sensing methods for thermal runaway (TR) mitigation due to the following critical performance benchmarks:
Gas Sensors vs. Pressure Sensors:
Although gas sensors provide rapid initial detection, they are highly prone to false positives caused by environmental contamination or aging. Additionally,they suffer from high power draw and require specific customization for different cell chemistries (e.g., LFP vs. NCM).
Temperature Sensors vs. Pressure Sensors:
Temperature sensors exhibit significant thermal lag because cell venting and gas evolution typically occur long before a measurable external temperature rise.
The Pressure Sensing Advantage:
Integrated inside the hermetic battery enclosure, a pressure sensor monitors internal pressure variations in real time. While nominal pack pressure stabilizes around 100 kPa, an early TR event triggers an instantaneous, sharp pressure spike before the pressure relief valve deploys. This allows the system to capture the transient phase immediately, providing a faster, more robust, and chemistry-agnostic safety alert.
