Comparison of the Chemical Stability of Li1−xCoO2 and Li1−xNi0.85Co0.15O2 Cathodes

✍ Scribed by R.V. Chebiam; F. Prado; A. Manthiram

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 303 KB
• Volume: 163
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9404

✦ Synopsis

The chemical stability of the layered Li 1؊x CoO 2 and Li 1؊x Ni 0.85 Co 0.15 O 2 cathodes is compared by monitoring the oxygen content with lithium content (1؊x) in chemically delithiated samples. The Li 1؊x CoO 2 system tends to lose oxygen from the lattice at deep lithium extraction while the Li 1؊x Ni 0.85 Co 0.15 O 2 system does not lose oxygen at least for (1؊x) 9 0.3. This di4erence seems to result in a lower reversible (practical) capacity (140 mA h/g) for LiCoO 2 compared to that for LiNi 0.85 Co 0.15 O 2 (180 mA h/ g). The loss of signi5cant amount of oxygen leads to a sliding of oxide layers and the formation of a major P3 and a minor O1 phase for the end member CoO 2؊ with ‫؍‬ 0.33. In contrast, Ni 0.85 Co 0.15 O 2؊ with a small amount of ‫؍‬ 0.1 maintains the initial O3 layer structure. 2002 Elsevier Science