摘要:
A process for the direct synthesis of high surface area amorphous chalcogenides of transition metals of Group IV, V, VI and VII elements, comprising the steps of:(1) forming a mixture of:(a) a halide of a said transition metal having the formula MY.sub.n where Y is chlorine, bromine, flurorine, or iodine, and n is 3, 4, 5 or 6, and(b) a source of chalcogen selected from compounds having the formula (R).sub.3 Si--X--Si(R).sub.3 wherein R is alkyl having from 1-4 carbon atoms and X is sulfur, selenium or tellurium,(2) reacting said mixture at a temperature of -77.degree. C. to +160.degree. C.;(3) separating the transition metal chalcogenide from the reaction mixture; and(4) washing said chalcogenide with an inert solvent to remove unreacted materials and the byproducts of the reaction.The high surface area amorphous chalcogenides prepared according to the covalent exchange process of the invention are advantageously used in primary or secondary batteries, particularly lithium cells. They are of amorphous chemical structure as shown by X-ray, Raman and infrared analysis. Their small crystal size, high surface area, and freedom from oxygen and water contamination, make them high activity, rechargeable cathodes in lithium cells.
摘要:
An efficient, low-temperature process for the preparation of highly pure, free-flowing aluminum nitride powder without oxygen contamination, comprising the steps of:(1) forming a mixture of ##STR1## and (b) AlCl.sub.3 ;(2) reacting the mixture formed in step (1) at a temperature of from 0.degree. C. to 150.degree. C. and thereby forming ##STR2## (3) maintaining the Cl.sub.2 --Al--NH--Si(CH.sub.3).sub.3 formed in step (2) at a temperature of from 170.degree. C. to 200.degree. C. and thereby forming Cl--Al--NH and (CH.sub.3).sub.3 --SiCl; and(4) maintaining the Cl--Al--NH formed in step (3) at a temperature of at least 450.degree. C. and thereby forming H.sub.2, Cl.sub.2, and AlN.