Silicon lithium metal

Lithium-ion batteries high energy density purified natural graphite carbon coated silicon graphite/metal composites chemical vapor deposition. 

The metals were coprecipitated with lead-ammonium pyrrolidine dithio-carbamate and detected by X-ray spectrometry following neutron activation. Magnetic fields deflect the p rays while the X rays reach the silicon (lithium) detector undeviated. The detectors have low sensitivity to y rays. The concentration of cobalt found by this method was 1.3 xg/l, about one-fifth of that measured previously, while that of copper, 2.0 xg/l, agreed with results obtained by some previous workers. The concentration of mercury was 1.2 xg/l. 

Preparative electrochemical reduction of aryltrimethylsilanes in methyl-amine in the presence of LiCl gives the Birch-type products, 1,4-cyclohexan-dienes (Scheme 34) [6], A mechanism involving the electrochemical formation of lithium metal which chemically reduces the substrate has been suggested. The hydrogen atom is introduced on the carbon adjacent to the silicon preferentially. This regioselectivity is consistent with the spin density of the anion radical determined by ESR spectroscopy (Sect. 2.2.1). 

As discussed in Section 2.2.2, an electron beam incident on a metal gives rise to the emission of characteristic X-rays from the metal. In electron microscopy, the elements present in the sample also emit characteristic X-rays. These are separated by a silicon-lithium detector, and each signal collected, amplified and corrected for... 

The cell operated at 300°C, at which temperature lithium metal is liquid, so that the lithium anode was replaced by a lithium-silicon alloy which is solid and which exhibits a reversible uptake of lithium, as discussed in Chapter 8. 

The reaction of cyclic silane 23 with lithium metal in THF opens an unexpected way to c-(MenSi6)Li (24). Whereas in tri-, tetra- and penta-cyclosilanes a Si—Si bond is cleaved under these conditions (Section VLB.3), 23 reacts with cleavage of a exocyclic Si—C bond (equation 35)85. The reasons for the different behavior of 23 toward lithium remain unclear. It was, however, suggested that the facile formation of 24 is due to its thermodynamic stabilization by electron delocalization into the silicon framework85. 

An interesting silacycloalkane containing silicon-silicon bonds in the ring (XVII) has been obtained by introducing isobutylene into a reaction mixture of dimethyldichlorosilane and lithium metal in tetrahydrofuran at 0°-10° C (137). 

Reduction of 2-chloro-l,3-diaza-2-silacyclopentanes with lithium metal in THF gives the corresponding lithium compound which was shown to be configurationally stable by NMR spectroscopy up to temperatures of 333 K in THF or 388 K in diglyme <20020M1319>. Reaction of the lithium compound with electrophiles can be used to functionalize the silaheterocycle at the silicon atom <20020M1319>. 

LITHIUM IRON SILICON see LHKOOO LITHIUM LACTATE see LHLOOO LITHIUM METAL (DOT) see LGOOOO LITHIUxM METAL, IN CARTRIDGES (DOT) see LGOOOO... 

A remarkable reaction leading to polysilanes in which silicon atoms possess fourfold silicon coordination was pubhshed by Maxka et al. Tetrakis(chlorodi-methylsilyl)silane, which was obtained from SiCl4, Li, HMe2SiCl, and CCI4 was coupled using lithium metal in tetrahydrofuran (THF) solution. [(SiMe2)4Si] was obtained as a waxy orange solid with a yield of approximately 90%. 

The preparation of cyclic polysilanes from dialkylchlorosilanes and lithium metal in tetrahydrofiiran presumably involves a silicon—lithium intermediate (125). 

Compounds containing Silicon-, Germanium-, Tii, and Lead-Nitrogen Bonds.—Molecular nitrogen is reductively silylated by MeaSiCl and lithium metal in the presence of a transition-metal catalyst to give tris(trimethyl-silyl)amine [reaction (101)]. Variable-temperature n.m.r. spectra for a number of compounds containing Si—N bonds in which potentially diastereo-... 

An enlargement of the silicon skeleton is possible by coupling reactions with lithium metal or silyllithium reagents [4-6]. The homocoupling of tris(diethylamino)-l-chloro-l,2-dimethyldisilane results in the linear hexakis(diethylamino)-l,2,3,4-tetramethyltetrasilane [7]. After treatment with HCl the hexachloro compound could be obtained. By the reaction of aminochlorophenylsilanes with... 

Formation of the SEI layer plays an important role on the cycling stability of silicon-based anodes. Kulova and Skundin [109] reported a method used to preform the SEI layer on an electrode surface (prior to initial cathodic polarization) by direct contact of silicon and lithium metal in the electrolyte. The electrolyte was 1-M LiC104 in a mixture of propylene carbonate (PC) and dimethoxyethane. This method effectively reduced the irreversible capacity of the amorphous silicon electrode. Pretreatment of nanometer-sized silicon in ethanol also can form functionalized surfaces on the silicon particles that improve adhesion of silicon-based electrodes. A stable capacity of 2,500 mAh/g after 25 cycles has been reported for ethanol-treated silicon electrodes [110]. 

Kulova TL, Skundin AM (2010) Elimination of irreversible capacity of amorphous silicon direct contact of the silicon and lithium metal. Rus J Electrochem 46 470-475... 

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