Structural Characterization of Li1−z−xNi1+zO2 by Neutron Diffraction

✍ Scribed by C. Pouillerie; E. Suard; C. Delmas

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 465 KB
• Volume: 158
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9092

✦ Synopsis

Li 1؊z Ni 1؉z O 2 (z ‫؍‬ 0.02, 0.07, and 0.25) and deintercalated Li x Ni 1.02 O 2 (x ‫؍‬ 0.82 and 0.63) phases were characterized by neutron di4raction. In all cases, the amount of nickel in the lithium sites was found to be identical to that deduced from X-ray di4raction experiments. The sensitivity of the neutron studies allowed us to show that no lithium ions are in the NiO 2 slabs for z ‫؍‬ 0.02 and 0.07. A Li/ Ni mixing appears only for the most lithium-de5cient phase leading to the [Li 0.73 Ni 0.27 ] 3b [Ni 0.98 Li 0.02 ] 3a O 2 cationic distribution for the Li 0.75 Ni 1.25 O 2 phase. Determination of the anisotropic atomic displacement parameters con5rms the results previously obtained from EXAFS data. The structural characterization of partially deintercalated phases was in good agreement with the XRD analysis. However, in the case of Li 0.63 Ni 1.02 O 2 , it gave evidence for the presence of a small amount of rhombohedral phase due to 6uctuations in the composition of the starting material.