| 摘要 |
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′zO7α, in which M and M′are metal ions of groups of 2 to 15 having an ionic radius between 0.5 and 0.8Åin an octahedral oxygen environment, v, w, x, y, z andαbeing associated by the relationships: 2α=−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.
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