Research on a MEMS pressure sensor for fast thermal runaway detection for lithium-ion batteries

An absolute pressure sensor based on SOI (Silicon-on-insulator) substrate for thermal runaway detection of lithium-ion batteries is studied. A simulation and analysis of the stress distribution within the rectangular island-square membrane composite structure and the piezoresistor is conducted. A piezoresistive pressure sensor chip with a planar size of 2.5 × 2.5 mm is selected. Research on fabrication processing and packaging methods for the sensor is carried out. The test results demonstrate that the sensor exhibits an accuracy of ±0.2% FS within a pressure range of 50 to 250 kPa when working in a temperature range of -40~120℃. The sensor meets the demand for thermal runaway monitoring of power batteries.