Some Aspects of LiMn2 O 4 Electrochemistry in the 4 Volt Range
| Autor: | G. Pistoia, Daniela Zane, Y. Zhang |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Range (particle radiation)
Renewable Energy Sustainability and the Environment business.industry Chemistry Inorganic chemistry Spinel Analytical chemistry Electrolyte engineering.material Condensed Matter Physics Electrochemistry Cathode Surfaces Coatings and Films Electronic Optical and Magnetic Materials Ion law.invention Semiconductor Electrical resistivity and conductivity law Materials Chemistry engineering business |
| Zdroj: | Journal of The Electrochemical Society. 142:2551-2557 |
| ISSN: | 1945-7111 0013-4651 |
| DOI: | 10.1149/1.2050052 |
| Popis: | LiMn 2 O 4 is a hopping semiconductor ( = 2 x 10 -6 Ω -1 cm -1 ) as is λ-MnO 2 obtained by full delithiation. A semiconductor-metal transition is not observed by Li + extraction because the critical Mn-Mn distance for this transition (2.743 A) is shorter than those observed for λ-MnO 2 and LiMn 2 O 4 (2.803 and 2.913 A, respectively). However, on Li + removal the charge-transfer resistance of the spinel decreases, perhaps as a consequence of enhanced Li + crossing of the electrolyte/cathode interface. A full charge/discharge cycle does not allow one to reinsert the same amount of Li + extracted as a consequence of a structural alteration. The abrupt voltage drop at the end of the cycle coincides with a unit cell parameter of ∼8.24 A, i.e., the same value of the original spinel. Spinels prepared at 700-750°C have electrochemical features different from those of spinels made at 800-900°C.In particular, Li + is more easily extracted from the former in a process which seems to create Li + ordering for x = 2/3 and x = 1/3 ion Li x Mn 2 O 4 . The self-discharge characteristics of fully oxidized spinels in different electrolytes have been examined. |
| Databáze: | OpenAIRE |
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