Method for the Production of Conductive Micro-Wires by Means of Carbonisation for the Production of Electrodes

Abstract

The invention relates to a method for the production of a conductive micro-wire from carbon nanotubes by means of carbonization, and the uses thereof in electro-chemical processes and devices, for example, as electrodes in electrical generators. The invention can be included in the field of manufacturing nanomaterials and carbon nanotubes, as well as electrodes for electro-chemical processes and electrical conductors.

Claims

1. A method for the manufacturing of a conductive micro-wire comprising the following steps (a) unwinding a carbon fiber of a starting material on a winder at a speed of between 16 cm/s and 100 cm/s to obtain a coil fiber; (b) carbonizing the coil fiber at a temperature of between 1000° C. and 2500° C. for a time between 1 s and 50 s to obtain carbon nanotubes; (c) weaving the carbon nanotubes fibers using fiberglass to obtain woven carbon nanotubes; and (d) introducing the woven carbon nanotube fiber in a microporous polymeric sheath of a thermosetting polymer, selected from polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalates and ethylene terephthalate; and wherein the starting material is a sheet material that comprises: 75% thermosetting polymers; the carbon fibers, located next to the polymer; and varnishes located covering the carbon fibers and the polymer.

2. The method according to claim 1, wherein the steps from (a) to (d) are carried out continuously.

3. The method according to claim 1, wherein the carbonization of step (b) is carried out using a carbonization device selected between a gas furnace with multiples flames in series and an electric arc furnace.

4. The method according to claim 3, wherein the carbonization device of step (b) is the gas flame furnace that uses a gas selected from butane, propane and oxyacetylene, and wherein the carbonizing is carried out at a temperature between 2400° C. and 2500° C. and for a time between 1.3 s and 3.5 s.

5. The conductive micro-wire obtained using the method described in claim 1, the conductive micro-wire comprising: unidirectional carbon nanotube fibers, with a longitudinal orientation of the long axis of the nanotubes towards the longitudinal direction of the conductive micro-wire; residue from the carbonization of the coil fiber and the varnish of the starting material, which is located between the sheets, thereby increasing the mechanical strength of the conductive micro-wire; fiberglass, located interlaced in the carbon nanotube fibers configured as a fabric binding element and for increasing the mechanical strength of the micro-wire; and the sheath of a microporous insulating polymer selected from polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalates and ethylene terephthalate, located around the carbon nanotubes fibers encapsulating said fibers in a tubular manner.

6-7. (canceled)

8. An electrode comprising the conductive micro-wire of claim 5.

9. The electrode according to claim 8, wherein the electrode is a cathode in electro-chemical primary electrical generators, an electrode in chlorination cells, an electrode in galvanic cells, an electrode in voltaic cells, electrode in voltaic cells or an electrode for producing metals in electrolytic tanks.

10. An electric conductor comprising the conductive micro-wire of claim 5.

Description

DESCRIPTION OF THE FIGURES

[0032] FIG. 1 shows a diagram of the method for obtaining the micro-wire from carbon nanotube fibres.

EXAMPLES

[0033] The invention will be illustrated below by means of tests performed by the inventors.

Example 1

[0034] Unidirectional carbon fibre coils (1) with a surface area of 50 cm wide and 100 m long are positioned, located in a winder (2) that unwinds said fibre. The unwound carbon fibres will be pulled from the winders towards a built-in gas furnace with multiple flames in series (3), using butane gas, in the inside thereof at a speed of 16 cm/s inside said furnace. The furnace is at a flame temperature of 2450° C., each section of the carbon fibres being heated at that temperature for 3 s. In said furnace the fibres enter from the winder and said fibre exits transformed into carbon nanotube fibres directed towards a fibre weaver (4) for weaving fibres, weaving with fibreglass. Once finished, the fabric obtained is introduced into a microporous polymer in the form of a wire.