Porous Nanostructured Semiconductor Materials/LLNL/Hydrogen storage
United States Patent Application 20050208376
Kind Code A1
Williamson, Andrew J. ; et al. September 22, 2005
Nanostructured materials for hydrogen storage
Abstract
A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.
Inventors: Williamson, Andrew J.; (Pleasanton, CA) ; Reboredo, Fernando A.; (Pleasanton, CA)
Correspondence Name and Address: Eddie E. Scott
Assistant Laboratory Counsel
Lawrence Livermore National Laboratory
BACKGROUND
[0003] Field of Endeavor
[0004] The present invention relates to nanostructured materials and more particularly to nanostructured materials for hydrogen storage.
[0005] State of Technology
[0006] U.S. Patent Application No. 2001/0016283 by Masashi Shiraishi et al for a carbonaceous material for hydrogen storage, production method thereof, and electrochemical device and fuel cell using the same, published Aug. 23, 2001, provides the following state of technology information, "In recent years, a recognition has been promptly spread that hydrogen is an ideal clean, inexhaustible energy source because it has a large chemical energy amount per unit mass and does not release toxic substances and earth warming gases upon use of hydrogen as fuel. In particular, fuel cells capable of converting a hydrogen energy into an electric energy has been actively developed. Such fuel cells are expected to be used, typically, as thermal sources for large-scale power generation and on-site private power generation, and as power sources for electric cars. The use of hydrogen as fuel, however, presents the following problems: namely, (1) since hydrogen is in a gaseous state at standard temperature and pressure, it is relatively difficult to handle as compared with coal or petroleum; (2) since the density of hydrogen is much smaller than that of coal or petroleum, the chemical energy per unit volume thereof becomes smaller (that is, the volume per unit chemical energy thereof becomes larger), to cause a problem with storage and transportation thereof; and (3) since hydrogen has possibilities of leakage and explosion, it is difficult to keep safety upon use of hydrogen as fuel. For utilization of hydrogen as fuel, therefore, it becomes a key-point how to store a large amount of hydrogen in a state transportable with safety, and studies have been made to establish a new practical hydrogen storage technology."
[0007] U.S. Patent Application No. 20030167778 by Keith Bradley et al for hydrogen storage in nanostructures with physisorption published Sep. 11, 2003, provides the following state of technology information, "Hydrogen storage is the key unsolved problem of producing fuel cells for hydrogen-powered automobiles or portable energy devices. In particular, storing hydrogen in large quantities safely and in a light container has proved prohibitively difficult so far."
SUMMARY
[0008] Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
[0009] The present invention provides a system for hydrogen storage. The system comprises a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material. The system is predicted to store between 1.6 and 3.2 weight % hydrogen, at STP. Adjusting the temperature from below to above the operating temperature of approximately 340-350K switches the material from storing to emitting hydrogen. The present invention has uses in vehicular applications. In addition to vehicular applications, another application of the present invention is in portable consumer electronic devices. In these devices the benchmark for energy storage is Lithium ion batteries. Hydrogen stored in Applicants' nano-material and combined with oxygen in a PEM fuel cell has an energy density of 4.3 MJ kg-1. This is approximately an order of magnitude higher than Li batteries (0.5 MJ kg-1), while the two media have similar weights and volumes.
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