Lithium ion battery comprising nanomaterials
A lithium ion battery includes a cathode ( 10 ) having a plurality of nanoparticles of lithium doped transition metal alloy oxides represented by the formula Li x Co y Ni z O 2 , an anode ( 20 ) having at least one carbon nanotube array ( 22 ), an electrolyte, and a membrane ( 30 ) separating the anode from the cathode. The carbon nanotube array includes a plurality of multi-walled carbon nanotubes ( 23 ). Preferably, an average diameter of an outermost wall of the multi-walled carbon nanotubes is in the range from 10 to 100 nanometers, and a pitch between adjacent multi-walled carbon nanotubes is in the range from 20 to 500 nanometers. In the carbon nanotube array, the lithium ions are able to intercalate not only inside the multi-walled carbon nanotubes, but also in the interstices between adjacent multi-walled carbon nanotubes. Thus a density of intercalation of the carbon nanotube array is significantly higher than that of graphite.
1. An anode assembly for a lithium ion battery, the anode assembly comprising:
a conductive substrate; and
a plurality of multi-walled carbon nanotubes formed on the substrate, the multi-walled carbon nanotubes being substantially parallel to each other and substantially perpendicular to the substrate.
2. The anode assembly as described in claim 1 , wherein an average diameter of an outermost wall of the multi-walled carbon nanotubes is in a range from 10 to 100 nanometers.
3. The anode assembly as described in claim 1 , wherein a pitch between any two adjacent multi-walled carbon nanotubes is in a range from 20 to 500 nanometers.
4. The anode assembly as described in claim 1 , wherein a plurality of lithium ions are intercalated not only inside the multi-walled carbon nanotubes, but also in interstices between adjacent multi-walled carbon nanotubes.