Researchers at Korea Advanced Institute of Science and Technology (KAIST) have developed a new technology that can diagnose and monitor the state of EV batteries with high precision using only small amounts of current, aiming to maximize long-term stability and efficiency.
The research team, led by Professors Kyeongha Kwon and Sang-Gug Lee from the School of Electrical Engineering, has developed electrochemical impedance spectroscopy (EIS) technology that measures the impedance magnitude and changes in a battery to evaluate battery efficiency and capacity loss. It can assess the state of charge (SOC) and state of health (SOH) of batteries, identify thermal characteristics and chemical/physical changes, predict battery life, and determine the causes of failures.
The EIS system can precisely measure battery impedance with low current disturbances (10 mA), minimizing thermal effects and safety issues during the measurement process. The system minimizes bulky and costly components, making it easy to integrate into vehicles. The researchers demonstrated its effectiveness in identifying the electrochemical properties of batteries under various operating conditions, including different temperatures and SOC levels.
The research, in which Young-Nam Lee, a doctoral student in the School of Electrical Engineering at KAIST participated as the first author, was published in IEEE Transactions on Industrial Electronics.
“This system can be easily integrated into the battery management system (BMS) of electric vehicles and has demonstrated high measurement accuracy while significantly reducing the cost and complexity compared to traditional high-current EIS methods. It can contribute to battery diagnosis and performance improvements not only for electric vehicles but also for energy storage systems (ESS),” Professor Kyeongha Kwon explained.
Source: KAIST
