Analysis of Different Battery Cells In Series Using Electrochemical Impedance Spectroscopy in Quality Testing of Starter Batteries

摘要

Electrochemical impedance spectroscopy is mainly used in this master thesis to estimate the effects of different states of a cell within a cell package in series (e.g. Lead acid battery). On of the six cells of the Battery was intentionally manipulated to study his reflection on the whole battery represented by impedance curves. Each cell of the battery has been excited and measured through separate measurement points, so each cell can be examined independently of others. Hundreds of FLA batteries from a production line with 5 most common defects have been prepared and tested. The whole failure cases have been meaningful through a specific test sequence detected. The test process used was in combination with an HRD End of line test machine, which discharges the batteries with high rate currents. In order to integrate the impedance analysis method in the quality control in a battery production line and still suitable for production takt time, the impedance will be measured just at certain frequencies to reduce the test time.