METAL-HYDROGEN SYSTEMS

Summary of Databases

Overview

The field of metal-hydrogen systems R&D has been active for more than a century, and especially so since the middle of the 20th century. Discoveries of easily rechargeable metal hydrides based on alloys and intermetallic compounds started about 1970 and led to a hydride renaissance and several proposed and commercial applications. A commonly used applications example is the nickel metal hydride (NiMH) battery that uses a metal hydride for the negative energy storage electrode.

A second potentially important application area is the storage of hydrogen fuel for vehicular propulsion and stationary power generation, e.g., in both cases fuel cells. We are rapidly reaching an era when we must seek alternatives to fossil fuels. The most promising alternative is hydrogen and we must continue metal hydride R&D as a potential way of safely and efficiently storing and transporting that hydrogen. These databases were created to aid the researchers and application engineers who are following that quest.

We offer a series of databases in varying content and detail:

Comprehensive Hydride Material Listings
Properties Database for selected hydriding materials
Hydride Applications
References
M-H Meetings Calendar

The Metal-Hydrogen Systems databases are based largely on hydride forming alloys, although some M-H systems that form H solid solutions are also included. Elemental hydrides are generally omitted (except for a few important elements included in the Hydride Properties database). Most of the alloys covered are nominally single phase, although many exceptions probably exist. Amorphous, nanocrystalline and multiphase alloys will be subjects of future databases. A brief description of each database is given below. See the introductory page for each database for more detail and search hints.

Hydride Alloy Listings

These databases are presented as a series of eight comprehensive historical listings of alloys that have been reported to form hydrides or H solid solutions (currently 2706 records). Each is based on a metallurgical or crystallographic class of alloy or intermetallic compound. Unlike the Hydride Properties Database (below), the Hydride Alloy Listings include only a few representative properties, mainly in the area of hydrogen-capacity and representative PCT (pressure - composition - temperature) thermodynamic properties.

Hydride Properties

This database contains more detailed engineering information on a limited number of alloys (currently 47 records). The alloys represented are those that have been used for applications or have special historical and scientific interest. Properties include composition, detailed PCT, H-capacity, enthalpy and entropy of hydriding, plateau slope and hysteresis, metallurgy and synthesis, activation, kinetics, cyclic stability, morphology, gas impurity effects, commercial suppliers, known applications and selected literature citations.

Applications

This database lists more than 350 specific hydride applications or application-related studies and reviews in the general areas of H-storage, H-processing, thermal, electrochemical, materials processing and others.

References

The references used in all the hydride databases (more than 1600) are located in a separate database. The Reference database can also be used in a self-standing mode, i.e., independently of the hydride databases. It is searchable either by using the usual bibliographic fields (author, co-author, year, journal, organization, etc.) or by keywords.

M-H Meetings Calendar

This is a compilation of world-wide conferences and symposia in the field of metal-hydrogen systems. It includes information on the basic parameters of the meetings (date, place, organization, abstract submission, etc.), as well as Internet or other address for obtaining further information. Anyone interested in having a meeting listed should forward the basic information to Gary Sandrock (gary.sandrock@sbcglobal.net).

Updating of the Databases

We will periodically update the Hydride databases as time and funding permit, hopefully at least once per year. The M-H Meetings database will be updated as often as new information becomes available. We urge the users of these databases to inform us of any perceived missing data. We welcome reprints of any published papers of your own you think applicable for inclusion. All inclusions of data must be reflected in publicly available documents. Suggested inclusions for the Hydride and Meeting databases should be sent to Gary Sandrock.

Prudent Use of the Data

The users of these databases should fully understand they represent only a door to the published literature. They are not meant to be be used for the design of hydride devices. The user should carefully read the background information associated with each database and the disclaimers. The original reference sources for each datum of interest should be read before it is utilized. As always with the published literature, be wary of erroneous data. In addition to errors in the original publications, occasional errors in reading graphs or converting units are possible. You would be wise to repeat the experiment if it is critical to your application or if any doubt exists. In general, no attempt has been made to filter the data, with the possible exception of the Hydride Properties database where some limited degree of selectivity has been made relative to our own personal experience.

We believe the information presented is a reasonably accurate representation of the data published; however, the International Energy Agency, U.S. DOE and Sandia National Laboratories can offer no warranty, expressed or implied, as to the accuracy, applicability or use of the information for the users' intended purposes.

Gary Sandrock
gary.sandrock@sbcglobal.net

George Thomas, Sandia National Laboratories
george.thomas@sbcglobal.net

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Last Updated May 2, 2002