The investigation technique differential electrochemical mass spectrom
etry (DEMS) combines cyclic voltammetry with mass spectrometry. DEMS m
easurements enables to detect on-line gaseous products formed by elect
rochemical reactions. A new, simplified experimental set-up is present
ed, which allows to expand this method to high concentrated electrolyt
e solutions. For inorganic electrolyte, elaborated for a rechargeable
Li/LiCoO2 battery system, the usually DEMS cell is improved as compact
thin-layer flow cell. Chlorine evolution - substantial for overcharge
protection in this battery system - is examined at Ni and Au electrod
es.