TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation: (I) is produced by treating a hydrolyzable Ti(IV) compound (a covalent compound, hydrolyzable salt or mixture of such compounds with a hydrolyzable compound of the dopant) with aqueous sodium hydroxide under hydrothermal conditions, for 2 hours to 5 days, especially 4-24 hours.Preferred Materials: (X) comprises crystalline regions (A) of (un)doped TiO2 material having the anatase structure and other regions (B) of oxidic, (un)doped TiO2 material having a structure other than that of anatase, rutile or brookite. Particularly (A) represents 1-80, best 10-70, wt.% of (X) and (B) 20-99 wt.%, and (X) has BET surface at least 40, best 50-200, m2/g. Suitable dopants are hafnium, zirconium, tin, germanium, aluminum or niobium, and the particles of (X) are agglomerates of primary particles, where 90% of these particles have diameter 5-500, preferably 20-100, nm. Not more than 10% of the fibers are longer than 100, preferably 60, microns, and the length:diameter ratio is at least 10:1, preferably 20:1. Dopants are present at 0.1-25, best 1-10, mole% and, for use in batteries or accumulators, they are particularly zirconium or tin. EXAMPLE - Titanium tetrachloride (8 ml) was hydrolyzed with deionized water (20 ml) then made up to 150 ml with 10 N sodium hydroxide solution, and heated for 6 hours at 250 degrees C to form sodium titanate fibers. These were washed several times with 5 N hydrochloric acid to form a fibrous titanium oxide hydrate, and this suspended in 0.1 N hydrochloric acid, then heated for 6 hours in an autoclave at 200 degrees C. The final product was a Ti(IV) oxide material with BET surface 80 m2/g, comprising 50% each of anatase and a phase that was none of anatase, rutile or brookite. This material was tested in a lithium battery and the cyclic voltammogram included two peaks, at 1.52 and 1.59 V relative to a lithium/lithium cation reference electrode, that were not present when anatase was used instead. These peaks provide an increase in charge capacity.