Method of making self-standing electrodes supported by carbon nanostructured filaments
The present disclosure is directed to methods for production of composites of carbon nanotubes and electrode active material from liquid dispersions. Composites thusly produced may be used as self-standing electrodes without binder or collector. Moreover, the method of the present disclosure may allow more cost-efficient production while simultaneously affording control over nanotube loading and composite thickness.
1. A method of making a self-standing electrode, the method comprising:
providing a liquid dispersion comprising carbon nanotubes or carbon fibers, and a liquid medium;
wet-depositing the carbon nanotubes or the carbon fibers from the liquid dispersion to a moving substrate, which is pre-deposited with an electrode active material, to form a composite comprising both the carbon nanotubes or the carbon fibers and the electrode active material; and
removing the composite from the substrate to form a self-standing electrode,
wherein the electrode active material is not mixed with carbon nanotubes or carbon fibers prior to wet-depositing the carbon nanotubes or the carbon fibers from the liquid dispersion to the moving substrate.
2. The method of claim 1 , further comprising compressing the composite.
3. The method of claim 1 , wherein the carbon nanotubes are selected from single-walled carbon nanotubes, multi-walled nanotubes, and a mixture thereof.
4. The method of claim 3 , wherein the carbon nanotubes comprise single-walled carbon nanotubes.
5. The method of claim 1 , wherein the liquid medium comprises a solvent selected from water, ethanol, alcohol, NMH, and mixtures thereof.
6. The method of claim 1 , wherein the liquid dispersion further comprises a surfactant.
7. The method of claim 1 , wherein the electrode active material is selected from oxides of Ni, Mn, Co, Al, Mg, Ti, Li, and mixtures thereof.
8. The method of claim 1 , wherein the electrode active material comprises lithium nickel manganese cobalt oxide.
9. The method of claim 1 , wherein the carbon nanotubes are produced in a synthesis reactor coupled with a collector,
the collector containing the liquid medium to capture the floating carbon nanotubes produced in the synthesis reactor, and
the synthesis reactor comprising a metal catalyst precursor, a carbon source, and nanotube growth promoter, and a carrier gas.
10. The method of claim 9 , wherein the carbon source is selected from hydrocarbon, carbon monoxide, carbon dioxide, and mixtures thereof; wherein the nanotube growth promoter is selected from thiophene and hydrogen gas; and wherein the carrier gas is selected from argon, hydrogen, nitrogen, and mixtures thereof.