The faradaic impedance of the lithium-sulphur dioxide system. A further examination of commercial cells

Impedance measurements have been made on Li/SO sub(2) (C) cells at various states of charge. The individual electrode impedances have been measured against a lithium reference electrode using a transfer function analyser. A model for the cathode behaviour is presented. From the values of the analogue circuit elements it is shown that there is a film on the undischarged cathode which initially impairs the behaviour. Over a large range of residual capacities the charge transfer resistance is relatively constant. There is evidence for the presence of absorbed intermediates at the carbon matrix.