Abstract: The invention relates to a method of preparing an oxide of formula Li.sub.x Mn.sub.y O.sub.z, in which x lies in the range 0 to 2, y lies in the range 1 to 3, and z lies in the range 3 to 4.5, x, y, and z being such that the oxide has a composition close to LiMn.sub.2 O.sub.4. According to the invention, the method comprises the following steps:a) a polymer complex of lithium and of manganese is prepared in the form of a gel or of a xerogel by causing a reducing polymer, copolymer or polymer mixture possessing complexing functions for lithium and manganese to react in a common solvent with an oxidizing lithium salt and with an oxidizing manganese salt, and by evaporating off the solvent, partially or in full; andb) the resulting lithium and manganese polymer complex is mineralized by the explosive oxidation-reduction technique to recover fine amorphous particles of the oxide of formula Li.sub.x Mn.sub.y O.sub.z.

Abstract: An electrochromic element useful in an electrochromic glass or mirror device and a process for making such element. The element is a five-layered structure including an electrolyte ion conducting layer interposed between first and second inorganic electrochromic layers which are interposed between a pair of conductive electrodes. The second inorganic electrochromic layer is amorphous. The first and second inorganic electrochromic layers are different and are capable of exhibiting color-forming properties complementary to one another upon the incorporation of at least one H, Li, Na, K, Ag, Cu or Tl ion. The electrolyte ion conducting layer may be a copolymer of ethylene oxide, butylene oxide or methyl glycidyl ether, and optionally a small amount of allyl glycidyl ether, along with an ionizable salt, or may be a polyurethane gel formed by reacting the copolymer with triisocyanate, along with an ionizable salt.

Abstract: There is provided an efficient method of storing hydrogen in materials of small mass and small volume. The products of the present invention comprise intimate mixtures (as opposed to alloys) of magnesium and other metals or alloys capable of forming hydrides. The hydrides are selected so that the hydrides have a substantially lower thermal stability than that of magnesium hydride.