Cobalt-intercalated layered

MnO has been also coated with PANl to improve its electrochemical performance. Shin et al found that the cobalt-intercalated layered manganese oxide (CLMO) displayed the excellent cyclability over 40 cycles, although it exhibited a low discharge capacity (143 mA h g at 40 mA g current density) [51]. After chemical oxidative polymerization of aniline... 

Since the discovery of high temperature superconductivity in cuprates, there has been intense interest in transition metal oxides with strongly layered, (quasi) two-dimensional (2D) crystal structures and electronic properties. For several years now alkali-metal intercalated layered cobaltates, particularly Na CoCL (NxCO)withx 0.50 — 0.75, have been pursued for their thermoelectric properties [1] IAX C0O2 is of course of great interest and importance due to its battery applications. The recent discovery[2] and confirmation[3-5] of superconductivity in this system, for x 0.3 when intercalated with H20, has heightened interest in the NxCO system. 

Robertson AD, Armstrong AR, Bruce PG (2000) Influence of ion exchange conditions on the defect chonistry and performance of cobalt doped layered lithiiun manganese oxide based intercalation compounds. Chem Commun 20 1997-1998... 

Wang X, Chen X, Evans DG, Yang W (2011) A novel biosensor ftn reduced L-glutathione based on cobalt phthalocyaninetetrasulfonate-intercalated layered double hydroxide modified glassy carbon electrodes. Sens Actuators, B 160 1444—1449... 

Anionic complexes can easily be prepared by the sulfonation of the aromatic rings in the complexes. Sulfonated cobalt phthalocyanine intercalated in a layered double hydroxide host was a stable catalyst for the oxidation of thiols162,163 and phenol derivatives.164 It was concluded that the complex has been intercalated with the plane of the phthalocyanine ring perpendicular to the sheet of the host (edge-on orientation) (Fig. 7.2). 

Recently, the cobalt(II)-tetrasulfonatophthalocyanine system was reinvestigated for its catalytic activity while intercalated into a Mg5Al2 -layered double hydroxide. The intercalate exhibited catalytic properties in the activation of atmospheric dioxygen for the oxidation of a thiolate to a disulfide (97a) and for the oxidation of 2,6-di-tert-butylbenzene to (nearly exclusively) the 2,6,2, 6 -tetra-tert-butyldiphe-noquinone (97b). In marked contrast to the results reported for the homogeneous catalyst, this intercalated catalyst remained active for... 

Ukrainczyk, L., Chibwe, M., Pinnavaia, T.J. Boyd, S. A. (1994). ESR study of cobalt(II) tetrakis(N-methyl-4-pyridiniumyl)porphyrin and cobalt(II) tetrasulfophthalocyanine intercalated in layered aluminosilicates and a layered double hydroxide. Journal of Physical Chemistry, 98, 2668-76. 

Perez Bernal, M. E., Ruano Casero, R. and Pinnavaia, T. J. (1991). Catalytic autoxidation of 1-decanethiol by cobalt(II) phthalocyaninetetrasulfonate intercalated in a layered double hydroxide. Catal. Lett. 11, 55. 

Chibwe, M. and Pinnavaia, T. J. (1993). Stabilization of a cobalt(II) phthalocyanine oxidation catalyst by intercalation in a layered double hydroxide host. J. Chem. Soc., Chem. Commun., 278. 

This compound was shown by neutron powder diffraction to adopt an unprecedented structure in which chains of C0O4 squares share comers to form chains that are linked to form a layer by H-bridges. The average cobalt oxidation state is 1.1+ and the C0O2 sheets in the starting material have been replaced with CoOHo,7 sheets in the oxide hydride product, which is consistent with a mechanism in which oxide vacancies created by oxide ion deintercalation are filled by intercalation of hydride ions. 

Cao, G. and Mallouk, T.E., Shape-Selective Intercalation Reactions of Layered Zinc and Cobalt... 

Fig. 3.3 Schematic of a rechargeable lithium battery in discharge/charge mode. The lithium ion is intercalated in the anode during charging and in the cathodes during discharging. The layered host lattice in the cathode and anode is also illustrated, considering a cathode composed of a lithium cobalt host and an anode composed of a crystalhne structure of hexagonal graphite...

It is known that commercialty available LlBs make use of layered LiCo02 in positive electrodes, though cobalt is expensive and poisonous [51, 62]. Hence, developing both environmentally friendty and cheap electrode materials in place of LiCo02 is an important issue in LIBs. The electrode reaction in LIBs depends upon the simultaneous intercalation/extraction of Li ion and electron into the active electrode materials. 

Unlike cobalt and nickel, manganese does not form a stable, pure LiMn02 phase and forms the spinel structure instead, named after the mineral of spinel (Table 1.3) with the composition of Lio.5Mn02, conunonly expressed as LiMn204. Manganese-based cathode materials are attractive mainly due to their low cost compared to cobalt and nickel. A wide variety of the hthiated manganese oxides with multiple structures and compositions (Li Mn 0 ratios) exist and many of these compounds can reversibly intercalate lithium, but amongst these materials, spinel materials and the layered derivatives are the most mature, to the point of commercial availability. Spinel-stractured materials will be discussed separately in the next part of this chapter. 

Immobilized cobalt(II) and zinc(II)phthalocyanine anchored on silica or intercalated in the galleries and cavities of layered double hydroxides (hydrotalcite) and NaX zeoMte catalyze or photocatalyze the oxidation of 2-mercaptoethanol and sodium thiosulfate. The activity of the immobilized catalysts for oxidation and photooxidation is lower than that of the complexes in homogeneous phase. This is due to the hindered diffusion of dioxygen and sulfur-containing compounds to the active catalyst sites. 

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