Improved impedance spectroscopy technique for status determinationof production Li/SO₃ batteries

摘要

The authors address the development of a technique to providereliable two-terminal impedance measurements on graduation cells. Thetechnique's value as a quality control tool and field tester werecriteria during its development. Accuracy and measurement time are twoareas of concern. An impedance spectroscopy measurement system was setup using a Hewlett Packard HP9836 computer with hard drive and printer,a Schlumberger I286 electrochemical interface and a Schlumberger I250frequency response analyzer. Since the concentration was on two terminalcells the working electrode of the electrochemical interface wasconnected to reference electrode 2 and the counter electrode wasconnected to reference electrode 1. Routine impedance measurements havebeen made on lithium/sulphur dioxide (Li/SO₂) cells using anequivalent electric circuit approach. The data obtained show thatnetwork analysis for production batteries can be achieved quickly andaccurately