Three Electrode Electrochemical Voltage Spectroscopy (TEVS): evaluation of a model lithium ion system

✍ Scribed by J. Barker

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 666 KB
• Volume: 40
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(95)00090-2

✦ Synopsis

Lithium ion cells incorporate two intercalation type electrodes which each demonstrate voltage profiles which are directly dependent on their relative states-of-charge. A new electrochemical technique, Three Electrode Electrochemical Voltage Spectroscopy (TEVS) is described which allows detailed information to be derived for both intercalation electrodes within a single experiment. Only minor modifications to conventional two electrode electrochemical cell designs are necessary for implementation of this technique. During the experimental procedure, both the pseudo-open circuit voltage (ecu) profiles and the corresponding differential capacity plots for the two electrodes can be collected. A model lithium ion cell, namely the Li, _,Mn,O,/Li

, +xMnZO,, system, has been initially investigated using the new technique. This system can be cycled utilizing the approximate 3 V and 4 V vs. Li/Li * voltage ranges. Around x = 0.68 in Li,_,Mn,O, and Li,,, Mn,O, was cycled in the cell under the prevailing TEVS test conditions.

The collected TEVS data is directly compared to previously reported findings on two-electrode cells which utilized lithium counter electrodes.