| Autor: |
Pedro Amorós, Ismael Saadoune, A. Almaggoussi, Mohamed Labrini, Helmut Ehrenberg, Joachim Brötz, Jamal Elhaskouri, Frieder Scheiba |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Electrochimica Acta. 111:567-574 |
| ISSN: |
0013-4686 |
| DOI: |
10.1016/j.electacta.2013.08.051 |
| Popis: |
A systematic study has been performed to investigate the structural and magnetic changes in LiNi 0.33 Mn 0.33 Co 0.33 O 2 , a member of the LiNi y Mn y Co 1–2 y O 2 series, upon chemical lithium deintercalation. Structural characterization of the chemically delithiated Li x Ni 0.33 Mn 0.33 Co 0.33 O 2 samples indicates that the initial rhombohedral symmetry (α-NaFeO 2 type structure) is maintained in the whole 0.3 ≤ x ≤ 1.0 composition range. Less than 1% variation in the hexagonal unit cell volume was evidenced showing a good structural stability of this sample. SEM pictures of the delithiated phases confirm this stability. Indeed, the particle size average undergoes a small decrease (from 180 nm at x = 1.0–130 nm for x = 0.3). The magnetic properties (SQUID and EPR) of Li x Ni 0.33 Mn 0.33 Co 0.33 O 2 compounds were also investigated. A simultaneous oxidation of Ni 2+ to Ni 4+ via Ni 3+ and Co 3+ to Co 4+ was observed upon lithium removal. EPR signals registered at 100 K, coupled to SQUID measurements, revealed strong antiferromagnetic interactions within the structure of this sample which became more pronounced by the delithiation process. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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