Integrated Sensors Based on Low-Temperature Co-Fired Ceramic Technology for the Inside Pressure and Temperature Monitoring of Lithium-Ion Batteries

Monitoring internal pressure and temperature in lithium-ion batteries is essential for investigating internal chemical reactions, failure mechanisms, and providing early warnings of thermal runaway. The existing sensors face challenges in withstanding the high temperatures and corrosive electrolytes inside lithium-ion batteries. This work develops an integrated sensor with high robustness using low-temperature co-fired ceramic (LTCC) technology, which incorporates a multilayer ceramic circuit board, a digital pulse temperature sensor, a MEMS pressure sensor, and a microcontroller. It offers the real-time monitoring of pressure and temperature with digital output and calibrated accuracy, achieving a pressure resolution of 1 kPa with 0.085% F.S. accuracy and a temperature resolution of 0.1 °C with deviations under 0.5 °C. The pressure and temperature signals are independently output with drift below 0.067 kPa/°C. The integrated sensors were implanted into a pouch and prototype lithium-ion battery, respectively, for charge-discharge cycle monitoring. The results demonstrated that the integrated sensors could detect cyclic variations in pressure and temperature during charging and discharging until battery failure. Furthermore, the integrated sensors showed high stability after being immersed 60 days in the corrosive electrolyte, suggesting their potential as a novel method for monitoring the internal pressure and temperature of lithium-ion batteries.