Researchers have unveiled a groundbreaking technology that allows for the accurate diagnosis and monitoring of battery conditions using minimal current. This innovation aims to enhance the long-term stability and performance of batteries.
Proper diagnosis of electric vehicle (EV) batteries is crucial for their effective management and safe operation. A team from KAIST has created a new technology that can assess and monitor the condition of batteries with great accuracy while utilizing only small amounts of current, which is expected to improve both the stability and efficiency of the batteries over time.
On October 17, KAIST, under the leadership of President Kwang Hyung Lee, announced that a research group led by Professors Kyeongha Kwon and Sang-Gug Lee from the School of Electrical Engineering has developed a form of electrochemical impedance spectroscopy (EIS) technology designed to enhance the stability and performance of large-capacity batteries used in electric vehicles.
EIS is an effective technique for measuring the impedance* of a battery, which helps evaluate its efficiency and any losses. It plays a critical role in determining the state of charge (SOC) and the state of health (SOH) of batteries. Additionally, EIS can provide insights into thermal features, changes in chemical/physical properties, predict battery lifespan, and identify potential causes of failures. *Battery Impedance refers to the resistance encountered by current flow within the battery, which is essential for assessing its performance and condition.
However, conventional EIS equipment tends to be costly and complicated, complicating its installation, operation, and upkeep. Furthermore, the application of current disturbances in the range of several amperes (A) to a battery can lead to considerable electrical stress, heightening the risk of battery failures or fires, thus complicating practical usage.
To overcome these challenges, the KAIST research team created and validated a low-current EIS system capable of diagnosing the health and condition of high-capacity EV batteries. This new EIS system accurately measures battery impedance using low current disturbances (10mA), which reduces thermal effects and safety concerns during the measurement process.
The system also eliminates the need for large and expensive components, making it easier to incorporate into vehicles. It has been validated as effective in identifying the electrochemical properties of batteries across varying operating conditions, including different temperatures and SOC levels.
Professor Kyeongha Kwon, the lead author of the study, stated, “This system can be seamlessly integrated into the battery management system (BMS) of electric vehicles and has shown high measurement accuracy while substantially lowering both the costs and complexity compared to traditional high-current EIS methods. It has the potential to advance battery diagnosis and enhance performance not only for electric vehicles but also for energy storage systems (ESS).”
