Abstract: The invention relates to active material for the negative electrode of secondary rechargeable lithium batteries, wherein the active material is based on doped or undoped carbon-bearing lithium titanium ramsdellite oxide with general formula Li2Ti3O7 or Li2.28Ti3.43O8. The active material comprises a carbon substituted ramsdellite phase having a general formula Li2?4cCc—Ti3O7, with 0.1<c<0.5, and more than 0.1 mol % of spinel phase having a general formula Li1+xTi2?xO4 with 0<x<0.33.

Abstract: An active material for a lithium battery electrode comprises a phase having the formula Li2+v?4cCcTi3?wFexMyM?zO7??, in which M and M? are metal ions of groups of 2 to 15 having an ionic radius between 0.5 and 0.8 ? in an octahedral environment, v, w, x, y, z and ? being associated by the relationships: 2?=?v+4w?3x?ny?n?z, with n and n? being the respective formal degrees of oxidation of M and M?; ?0.5?v?0.5; y+z>0; x+y+z=w; and 0<w?0.3; and wherein at least part of the lithium is substituted by carbon according to the relationship 0<c(2+v)/4. The invention also includes a method for synthesizing the active material which comprises mixing and grinding the precursor compounds containing the metal components, carbon and oxygen; heating the mixture in an inert atmosphere at a temperature of 950 to 1050° C. in order to make a ceramic phase; and rapidly cooling the ceramic phase to produce the active material.

Abstract: The present invention relates to lithium cells, accumulators and batteries, and more particularly an active material for the negative electrode of rechargeable batteries. It concerns more particularly a material comprising a phase having a general formula Li2+v?4cCcTi3-wFexMyM?zO7?, in which M and M? are metal ions of groups of 2 to 15 having an ionic radius between 0.5 and 0.8 ? in an octahedral oxygen environment, v, w, x, y, z and ? being associated by the relationships: 2?=?v+4w?3x-ny-n?z, with n and n? the respective formal degrees of oxidation of M and M?; ?0.5?v?+0.5; y+z>0; x+y+z=w; and 0<w?0.3; characterized in that at least part of the lithium is substituted by carbon according to the relationship 0<c?(2+v)/4. The material has improved mass and volume capacities that may reach 190 Ah/kg, while preserving the previously acquired advantages, notably: a small loss of capacity at the first cycle, of 2 to 10 Ah/kg; excellent cyclability; low polarization of 30 to 70 mV in C/15 régime.