Material based on carbon and silicon nanotubes that can be used in negative electrodes for lithium batteries
The invention relates to a material comprising carbon nanotubes, deposited at the surface of each of which is a substantially continuous film of nanoscale silicon particles, that can be used in negative electrodes for a lithium battery.
1. A lithium battery comprising at least one electrochemical cell comprising:
a negative electrode comprising a material comprising carbon nanotubes, wherein a substantially continuous film forming a sheath of nanoscale silicon particles is deposited on the surface of each nanotube in the form of a sheath around each nanotube;
a positive electrode; and
a separator placed between said negative electrode and said positive electrode,
wherein the separator comprises a lithium-ion conductive electrolyte.
2. The lithium battery according to claim 1 , in which the positive electrode comprises a material selected from the group consisting of lithiated transition metal phosphates, lithiated transition metal oxides, and mixtures thereof.
3. The lithium battery according to claim 1 in which the positive electrode comprises at least one material selected from the group consisting of LiFe x 1 Mn 1−x 1 PO 4 with 0≦x 1 ≦1, and LiCoO 2 , LiNiO 2 , LiMnO 2 , and LiAlO 2 .
4. The lithium battery according to claim 1 , in which the separator is in the form of a porous component containing a lithium-ion conductive liquid electrolyte.
5. The lithium battery according to claim 4 , in which the lithium-ion conductive liquid electrolyte comprises an aprotic liquid solvent in which a lithium salt is dissolved.
6. The lithium battery according to claim 5 , in which the aprotic liquid solvent is a carbonated solvent.
7. The lithium battery according to claim 6 , in which the carbonated solvent is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate.
8. The lithium battery according to claim 5 , in which the lithium salt is at least one selected from the group consisting of LiPF 6 , LiClO 4 , LiBF 4 , LiAsF 6 , LiCF 3 SO 3 , LiN(CF 3 SO 2 ) 3 , and LiN(C 2 F 6 SO 2 ).
9. The lithium battery according to claim 1 , in which the film has a thickness ranging from 1 to 50 nm.
10. The lithium battery according to claim 1 , in which the carbon nanotubes are positioned substantially parallel to one another.
11. The lithium battery according to claim 1 , in which the carbon nanotubes are attached to a substrate via one of their ends.
12. The lithium battery according to claim 11 , in which the carbon nanotubes are positioned substantially perpendicular relative to the substrate.
13. The lithium battery according to claim 11 , in which the substrate is electrically conductive.