Reactions of Intercalates

The particle size of the cathode material plays a very important role in their electrochemical behavior [113]. Smaller particles provide the performance of the heterogeneous reaction of intercalation/deintercalation in the kinetic regime. One of the problem is to enhance electronic conductivity of cathode materials. In this case, electronic additives (e.g., carbon) could be excluded. 

In the particular case of lithiation or delithiation of cathode materials used in lithium secondary batteries, the calculation of the electrochemical equivalent involves an additional parameter related to the reaction of intercalation of lithium cations into the crystal lattice of the host cathode materials. Consider the theoretical reversible reaction of intercalation of lithium into a crystal lattice of a solid host material (e.g., oxide, sulfide) ... 

The combination of the heat generation by two reactions, the decomposition of the metastable components of the SEI and the reaction of intercalated Li with electrolyte to form stable SEI, caused the cell temperature to increase. They can be expressed as a heat generating function as follows [52] ... 

The similarity of M0S2 to graphite has been noted. Like elemental carbon, which has been found to form nanotubular stmctures, M0S2 has also been found to form nested stmctures upon exposure to the electron beam in an electron microscope (23). Moreover, M0S2 displays a variety of intercalation reactions typical of layered materials. Single-layer M0S2 has been successfully prepared and manipulated (22). 

The most important rechargeable lithium batteries are those using a soHd positive electrode within which the lithium ion is capable of intercalating. These intercalation, or insertion, electrodes function by allowing the interstitial introduction of the LE ion into a host lattice (16,17). The general reaction can be represented by the equation ... 

The reaction of iodine heptafluoride is accompanied by reduction to the pentavalent state (S15). The intercalation process can thus be described in terms of the reaction... 

Perhaps the most convincing argument in favor of intercalant ionization derives from the analogous reaction of graphite with OsFg (B22). The product, formulated as CJOsFs, obeys the Curie-Weiss law, and has a magnetic moment characteristic of OsFs(V) salts. 

The reactions of hexafluorides with graphite may thus involve both intercalation and oxidation, a phenomenon that has been encountered to a greater or lesser degree with other fluorides, depending on their reactivities. 

Hie reactions of 4-chloropyridines and quinolines 17 with benzotriazoles 18 in a modified Graebe-Ullman synthesis give excellent yields of Y arbolines and their benzo-fused derivatives 20. Excellent yields for preparation of the penultimate benzotriazole precursors 19 are reported as well. In the optimized one-pot conditions, the combined neat substrates are heated with microwave irradiation (MW) for short (7-10 min) durations. The crude 19 is treated with H4P2O7 and irradiated futher (4-6 min). The resultant y-carbolines 20 were methylated to form the quaternary salts. These were tested and found to lack DNA intercalation properties <96JOC5587>. 

This i>aper describes two broad types of intercalation conpomds which are based on graphite on the one hand and sheet aluminosilicate (clay) hosts on the other. Taken together these provide a rich veiriety of examples of heterogeneously catalysed reactions. Appropriately cation exchanged clays, for example, act as efficient catalysts for a number of commercially important proton catalysed reactions (10-13) (see Table I). Graphite intercalates, whilst also capable of... 

Palladium hydride is a unique model system for fundamental studies of electrochemical intercalation. It is precisely in work on cold fusion that a balanced materials science approach based on the concepts of crystal chemistry, crystallography, and solid-state chemistry was developed in order to characterize the intercalation products. Very striking examples were obtained in attempts to understand the nature of the sporadic manifestations of nuclear reactions, true or imaginary. In the case of palladium, the elfects of intercalation on the state of grain boundaries, the orientation of the crystals, reversible and irreversible deformations of the lattice, and the like have been demonstrated. 

Insertion (intercalation) compounds. Insertion compounds are defined as products of a reversible reaction of suitable crystalline host materials with guest molecules (ions). Guests are introduced into the host lattice, whose structure is virtually intact except for a possible increase of some lattice constants. This reaction is called topotactic. A special case of topotactic insertion is reaction with host crystals possessing stacked layered structure. In this case, we speak about intercalation (from the Latin verb intercalare, used originally for inserting an extra month, mensis intercalarius, into the calendar). 

Intercalation of some guest species, such as alkali metals, can simply be performed via a chemical reaction of a gaseous reactant with graphite. 

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