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Carbon nanotube reinforced porous carbon having three-dimensionally ordered porosity and method of fabricating the same

This application is a divisional application of commonly-owned patent application Ser. No. 11/190,212, filed Jul. 25, 2005.

The invention described herein was made in part by an employee of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

1. Field of the Invention

This invention relates to porous carbon. More specifically, the invention is a porous carbon having three-dimensionally ordered porosity and carbon nanotube reinforcement, as well as a method of fabricating same.

2. Description of the Related Art

Porous carbon is being considered for use in a variety of applications to include electrochemical energy storage devices, thermal dispersion devices, and electric charge dispersion devices. For example, in terms of electrochemical energy storage devices, porous carbon may provide the requisite storage capacity for hydrogen when hydrogen is to be used as an energy carrier in high-energy density rechargeable batteries or hydrogen-oxygen fuel cells. In particular, micro-porous carbon foams are promising candidates for the hydrogen storage objective since porous carbon foam presents a large surface area for hydrogen absorption. However, porous carbon foams are mechanically weak. Further, the non-uniform nature of the porosity of these carbon foams is a drawback for applications requiring precise porosity control.

The non-uniform porosity problem is addressed in U.S. Pat. No. 6,261,469 where glassy porous carbon structures are constructed by providing an opal-like lattice structure of silicon dioxide spheres, infiltrating a carbon precursor into the lattice structure, carbonizing the carbon precursor, and then dissolving the silicon dioxide spheres. However, the resulting porous structure is mechanically weak.

Accordingly, it is an object of the present invention to provide a porous carbon structure having good mechanical strength.

Another object of the present invention is to provide a porous carbon structure having uniform porosity.

Still another object of the present invention is to provide a method of fabricating a porous carbon structure that will have both good mechanical strength and uniform porosity.

Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.

In accordance with the present invention, a method of fabricating a three-dimensional structure utilizes a template made from spheres arranged and coupled together to form an opal-like lattice having volumetric spaces formed between the spheres. The volumetric spaces are filled with a cured form of a carbon yield material having carbon nanotubes (CNTs) dispersed therein. The carbon yield material is then carbonized and the spheres are eradicated, leaving behind spherical voids. As a result, the three-dimensional structure comprises solid carbon having CNTs dispersed therein. The solid carbon with CNTs dispersed therein is thus formed about three-dimensionally ordered spherical voids arranged in the opal-like lattice.