A Low-Cost, Small-Size, Low-Power Ultrasonic Embedded Sensor System for In-Situ Monitoring of State-of-Charge and State-of-Health of Lithium-Ion Batteries

D. Xiang
X-waveInnovations.com, MD

Estimation of the battery’s State of Charge (SOC) and State of Health (SOH) is the main focus of a Battery Management System (BMS) to control the charging and discharging limits for the safe use and prevention of thermal runaways of Lithium batteries. Improving battery SOC, SOH, and failure detection accuracy involves new sensors and algorithms to extract more and relevant information from the cells in a battery pack. This new sensor technology should be easy for implementation and low cost. In this work, X-wave Innovations, Inc. developed a unique low-cost, small-size, low-power ultrasonic embedded sensor system that utilizes a set of transducers capable of detecting SOC, SOH and minimizing internal battery failure precursors for SOC, SOH, and early failure detection of Lithium-ion cells. The ultrasonic embedded sensor system can detect abnormalities before the battery starts showing external signs of degradation or possibly before voltage, temperature and current in the cell can indicate abnormalities. By integrating this ultrasonic sensor system with existing SOC, SOH approaches (i.e., voltage, current and temperature) together, a complete BMS with improved accuracy and reliability for in-situ SOC and SOH detection, as well as capability of early warning of cell failure in Lithium batteries can be achieved.