Manganese-cobalt spinel

Linde et al. (138) have studied propene oxidation under static conditions at low pressures over manganese-cobalt spinels. The reaction rate was found to be proportional to coverage of the surface with oxygen and independent of the hydrocarbon concentration. 

Complex compounds of lithium and heavy metal oxides as nickel oxide and cobalt oxide are working more effectively than the lithium/manganese oxide spinel which incorporates lithium ions into its tube like voids whereas the former with their layered structure take up and release lithium ions more easily. 

Fig. 2.10 Challenges in electrode materials for Li-ion batteries. LFP lithium iron phosphates. NMC nickel-manganese-cobalt oxide. NCA nickel-cobalt-aluminum oxide. LMS lithium-manganese spinel. Ranking 1 = worst, 5 = best...

Cobaltites with spinel stractnre have compositions MC02O4, where M is a metal forming divalent cations, snch as zinc, cadminm, magnesinm, nickel, manganese, and divalent cobalt. In contrast to the perovskites, the cobaltites have a rather high catalytic activity already at room temperatnre. Experiments show that the activity increases with increasing spinel structure content (i.e., increasing number of Co ions) of the catalyst snrface. The trivalent cobalt ions promote the withdrawal of... 

Soled S.L., Iglesia E., and Fiato R.A. 1992. Copper-promoted cobalt manganese spinel catalyst and method for making the catalyst for Fischer-Tropsch synthesis. U.S. Patent 5162284. 

Spectra of the mixed spinels are interpretable in terms of X-ray diffraction studies of the same samples by Azdroff (16). Cobalt appears to be in the divalent condition, based upon the location of the principal maximum. Manganese appears in a higher valence state. The extended fine structure, which is supposed to be determined by the lattice, appears identical for all the spectra of Figs. 14 and 15 which are of truly cubic spinels, namely CosOi,... 

Fio. 15. Manganese K-edge spectra of five mixed oxides, including two whose cobalt edge spectra were included in Fig. 14. Mni04 and CojMniOa are tetragonal others are cubic spinels. 

Figure 18. Galvanostatic discharge curves at room temperature and at 0.1 mA cm for layered cobalt and nickel oxides, and spinel manganese oxide in ethylene carbonate-diethyl carbonate-LiN(CF3S02)2 [134] (by permission of Elsevier Seience S.A. S. Megahed, B. Scrosati, J. Power...

Cobalt, copper, chromium and manganese oxides are mainly used for melt coloration. The colorants used are, in the main, those used in the ceramic industry e.g. oxides such as chromium(III) or iron(IIl) oxides spinels such as C0AI2O4 rutile, zirconium and tin colorants. 

While a diversity of active materials are apphed in the positive electrodes of primary lithium cells, the choice of the positive electrode in lithium ion batteries is limited. The positive electrodes of lithium ion batteries are made almost exclusively of lithiated cobalt or nickel oxides and of lithium-manganese spinels. 

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