摘要:
The invention relates to a nanostructured material. Said material is a nanostructured carbon material consisting of agglomerates of small needles of Li1+aV3O8 and ßLixV2O5 (0,l≤ α ≤ 0,25 et 0,03 ≤ x ≤ 0,667 surrounded by a discontinuous coating of spherical carbon particles. It is obtained by means of a process consisting in preparing a carbon precursor gel by bringing carbon, V2O5- α an a Li precursor into contact with each other, the amounts thereof being such that the ratio of concentrations [V2O5]/[Li] ranges from 1.15 to 1.5, and the mass ratio (carbon)/ (carbon + V2O5+ Li precursor) is 10 to 15, and in subjecting the gel to heat treatment including a first stage at 8O0C - 15O0C pendant 3-12 h, and a second stage between 3000C and 35O0C, during 10 mins to 1 hour, in a nitrogen or argon atmosphere. n. Applications: positive-electrode active material.
摘要:
The invention relates to a nanostructured material. Said material is a nanostructured carbon material consisting of agglomerates of small needles of Li1+aV3O8 and ßLixV2O5 (0,l≤ α ≤ 0,25 et 0,03 ≤ x ≤ 0,667 surrounded by a discontinuous coating of spherical carbon particles. It is obtained by means of a process consisting in preparing a carbon precursor gel by bringing carbon, V2O5- α an a Li precursor into contact with each other, the amounts thereof being such that the ratio of concentrations [V2O5]/[Li] ranges from 1.15 to 1.5, and the mass ratio (carbon)/ (carbon + V2O5+ Li precursor) is 10 to 15, and in subjecting the gel to heat treatment including a first stage at 8O0C - 15O0C pendant 3-12 h, and a second stage between 3000C and 35O0C, during 10 mins to 1 hour, in a nitrogen or argon atmosphere. n. Applications: positive-electrode active material.
摘要:
The invention relates to a method for preparing a lithium and vanadium oxide and the thus obtained products consisting in preparing a precursor gel by reacting hydrogen peroxide with V2O5-α in an aqueous medium in the presence of a lithium precursor and in exposing said gel to a heat treatment in an oxidant atmosphere at a temperature ranging from 260 °C to 580 °C. A compound of a formula Li1+α V3O8, (0,1=α= 0,25) consists of needle-shaped grains having a bimodal distribution, wherein the length (L) of the first distribution needles ranges from 10 to 50 νm and the length (L) of the second distribution needles ranges from 1 to 10 νm. When l is the grain width, L the length and e the thickness thereof, said dimensions are such as 4
摘要:
The invention relates to a lithium and vanadium oxide. The oxide corresponds to formula Li1+α V3O8 (0,1≤ α ≤0,25) and is made up of agglomerates of small needles whose length L is 400 - 1000 nm, whose width is such that 10
摘要:
The invention relates to the preparation of a Ϝ-LiV2O5 optionally carbon material. The method consists in preparing a composition consisting of carbon and Li and V precursors, and in subjecting it to thermal treatment. The composition is prepared by bringing carbon, V2O5-α and a Li precursor into contact, the quantities thereof being such that the ratio of concentrations [V2O5]/[Li] is 0.95 1.05, carbon exceeding by at least 25 % in relation to the stoichiometry. Thermal treatment is carried out in two stages: a first stage at a temperature of 90 °C -150 °C during 1 -12 hours; a second stage at a temperature of 420 °C - 500 °C, during 10 mins - 1 hour, in a nitrogen or argon atmosphere or in a vacuum. Applications: positive-electrode active matter.