Presentation Description: This presentation will introduce Electrochemical impedance spectroscopy (EIS) applications on EV batteries. EIS was used in medical fields for disease analysis by detecting changes of organic cells a decade ago. The same principle can be used on battery cells. EIS is a non-destructive tool able to extract internal information about the battery's electrochemistry by applying sinusoidal excitation signals to the batteries. In electric vehicles, many batteries cells are combined to build 400V or 800V power systems. The concerns about the battery reliabilities, life time usage, charge speed, mileage range hamper the consumers from purchasing EVs. How to use EIS technologies is a hot topic. We are studying this technology on the battery pack level, and would like to share our experiences of topology selection, circuit design, EIS data analysis, and so on.
