Positive electrode materials with high operating voltage for lithium batteries: LiCryMn2 − yO4 (0 ≤ y ≤ 1)

Sigala, Catherine; Guyomard, Dominique; Verbaere, A.; Piffard, Y.; Tournoux, M.

doi:10.1016/0167-2738(95)00163-z

Cited by 312 publications

(158 citation statements)

References 7 publications

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“…The precursors used for the Ni-substituted spinels were Mn(ac) 3 • 2H 2 O and Ni͑ac) 2 • 4H 2 O (ac ϭ acetate). The starting materials were thoroughly mixed and heated in air at 500°C for 4 h or at 800°C for 6 h. Samples were reground by hand and annealed at 500 or 800°C for 24 h. The three sample series were designated M500 or M800, depending on their synthesis temperature, M being the substituting transition metal.…”

Section: Methodsmentioning

confidence: 99%

“…Three series of cation-substituted lithium manganese spinels of nominal composition LiM 0.2 Mn 1.8 O 4 (M ϭ Cr,Ni,Cu) were prepared from appropriate amounts of Li 2 CO 3 ͑Merck͒ and freshly prepared Mn͑acac) 3 , Cr͑acac) 3 , or Cu͑acac) 2 (acac ϭ acetylacetonate) by using a conventional ceramic method at two different temperatures ͑500 and 800°C͒. The precursors used for the Ni-substituted spinels were Mn(ac) 3 • 2H 2 O and Ni͑ac) 2 • 4H 2 O (ac ϭ acetate).…”

Section: Methodsmentioning

confidence: 99%

“…1 LiM x Mn 2Ϫx O 4 spinels (M ϭ V 5ϩ , 2 Cr 3ϩ , 3 Fe 3ϩ , 4 Co 3ϩ , 5 Ni 2ϩ , 6 Cu 2ϩ , 7 and Al 3ϩ 8 ͒, in addition to LiMn 2 O 4 itself, 9 have been found to exhibit this peculiar behavior. While the oxidation of M may account for the electrochemical reaction yielding the plateau, that of V 5ϩ , Al 3ϩ , or even LiMn 2 O 4 is not so clearly associated with this phenomenon.…”

mentioning

confidence: 99%

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Oxygen Lattice Instability as a Capacity Fading Mechanism for 5 V Cathode Materials

Caballero

Hernán

Melero

et al. 2005

J. Electrochem. Soc.

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The origin of the overcharge in the 5 V region observed in lithium-substituted LiM x Mn 2Ϫx O 4ϩ␦ spinels (M ϭ Cr, Ni, Cu; x Ϸ 0.2) prepared at 500°C was analyzed by using accurate analytical spectroscopic techniques ͑mass spectroscopy, nuclear magnetic resonance͒ to examine the electrolyte behavior. The spectra revealed organic solvents to be stable as no decomposition products were detected, thus excluding the electrolyte oxidation as a side reaction accounting for the cell overcharge. However, these spinels contain excess oxygen in an amount that was quantified from thermogravimetric data. The excess oxygen plays a prominent role in the electrochemical response of the spinel. The cyclic voltammetry and galvanostatic results support the assumption that the excess oxygen can be released above 4.5 V. The additional capacity obtained and that required to release the oxygen were quite consistent. This must be the origin of both the overcharge and the poor performance of the cells compared with spinels of similar composition but synthesized at higher temperatures ͑800°C͒, the excess of oxygen in which was smaller. The ability of some Li-Mn based spinels to exhibit high-voltage plateaus at about 5 V has opened up new prospects for lithium batteries such as the possibility of manufacturing high-voltage batteries capable of supplying highly specific energy.1 LiM to Mn 5ϩ or Mn 6ϩ hypothesized for the undoped spinel has not yet been confirmed. Two alternative side reactions can be considered: ͑i͒ electrolyte oxidation above 4.6 V and (ii) a redox process undergone by the oxygen lattice of the spinel framework involving release of oxygen. This latter model can be related with theoretical computations based on either first-principles calculations 10 or the DV-X␣ molecular orbital model.11 Based on such models, when M is substituted by Mn ions, a new O 2p band at a low energy is responsible for the high electrochemical cell voltage observed. Simultaneously, evolved oxygen may oxidize organic solvents. These unwanted side reactions can lead to a premature cell capacity loss. Three recent reports 12-14 have insisted on the origin of the electrochemical activity above 4.5 V. Thus, Wang et al. 12 claim that the high voltage capacity of Li 1ϩx Mn 2Ϫx O 4Ϯz originates from the extraction of Li ϩ at 16d sites, whereas Shin and Manthiram 13,14 ascribe it to the involvement of O 2Ϫ -2p in the redox process. The aim of this work was to help clarify the processes taking place in the high-potential region of 5 V in cation-substituted lithium manganese spinels. For this purpose, Cr-, Ni-, and Cusubstituted spinels containing the doping elements in various oxidation states and prepared at two different temperatures ͑500 and 800°C͒ were examined. The electrolyte decomposition was analyzed using mass spectrometry ͑MS͒ and nuclear magnetic resonance ͑NMR͒ measurements. These measurements, together with thermogravimetric ͑TG͒ data, confirmed the central role played by the excess oxygen ion in the spinel lattice. ExperimentalThree series ...

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Oxygen Lattice Instability as a Capacity Fading Mechanism for 5 V Cathode Materials

Caballero

Hernán

Melero

et al. 2005

J. Electrochem. Soc.

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“…Based on the results obtained with the systems LiMn 2−y Ni y O 4 and LiCr y Mn 2-y O 4 , Dahn and Sigala [18,19] previously pointed out that the high voltage originated from the oxidation of nickel and chromium ion. The 4.1 V plateau was related to the oxidation of Mn 3+ to Mn 4+ and the 4.7 V plateau to the oxidation of Ni 2+ to Ni 4+ .…”

Section: Mechanism Of High Voltage and Insertion/deinsertionmentioning

confidence: 99%

LiNi0.5Mn1.5O4 Spinel and Its Derivatives as Cathodes for Li-Ion Batteries

Liu¹

2012

Lithium Ion Batteries - New Developments

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“…Then, on cycling, the spinel structure is destroyed due to a cubic-tetragonal phase transition induced by Jahn-Teller distortion (David et al, 1987;Gummow et al, 1993;Gummow and Thackeray, 1994). For this reason, batteries with LiMn 2 O 4 cathodes show capacity loss and poor cyclability Myung et al, 2000 (Sigala et al, 1995). It can be assumed that Mn plays an important role to stabilize the structure of the chromium oxide.…”

Section: Lithium Manganese Oxide (Limn 2 O 4 )mentioning

confidence: 99%