Design and Development of AC Impedance Measurement Test Circuit for Lithium-ion Cells

Electrochemical impedance spectroscopy (EIS) is a commonly used method to determine the impedance of the battery, which is a direct indicator of its health. However, the impedance measurement equipment available in the market is very costly and limited to operating points and conditions. To solve this impedance measurement issue, the design and development of a low-cost cell impedance measurement setup at a wide frequency range is proposed. The proposed setup can work at a wide frequency range, from mHz to several kHz, and offers the user a versatile solution for application in conjugation with different environmentally controlled test chambers. The article will present the design approach, analysis, laboratory demonstrator design, and validation results of the innovative test setup proposed.