Metal hydride alloy

J J. R. Johnson, S. Mukerjee, G. D. Adzic, J. J. Reilly, J. McBreen, In situ XAS studies on AB2 type metal hydride alloys for battery ap-... 

Hydride Compressors using reversible metal hydride alloys offer an economical alternative to traditional mechanical compressors for GH2. The simplicity and passive operation of the hydride compression process offers many advantages over mechanical compressors. Hydride compressors are compact, silent, do not have dynamic seals, require very little maintenance, and can operate unattended for long periods. However, they are a very new and may be difficult to be built at the scale required for GH2 transmission pipeline service. 

Zaluska, A., L. Zaluski, and J.O. Strom-Olsen, Lithium-beryllium hydrides The lightest reversible metal hydrides,. Alloys Compd., 307,157,2000. 

Hydrogen Weight Alloy Weight Fig. 5.7 Hydrogen absorption capacity of metal hydride alloy... 

Fetcenko M.A, Venkatesan S., Ovshinsky S.R. (1992) Selection of metal hydride alloys for electrochemical applications, Proc. Symp. on Hydrogen Storage Materials, Batteries and Electrochemistry, PV 92-5, 141-167. 

Giither, V., Otto, A. (1999). Recent developments in hydrogen storage applications based on metal hydrides. /. Alloys Compounds 293-295, 889-892. 

A new controlled dry cutting method that non-destructively cuts nanotubes without incorporating a metal hydride alloy has been developed. 

Incorporate improved metal hydride alloys and improve heat exchanger design along with additional engine work to increase the range from present 35 kilometers (km) to greater thanlSO km. ... 

In addition to vehicle optimization, we will use higher capacity metal hydride alloys developed at ECD, coupled with improved heat exchangers. This improved metal hydride storage system will be integrated into the vehicle for optimum utilization of waste heat. Detailed performance characteristics under different sets of driving conditions will determine areas of further improvement if necessary. 

Metal Hydride Alloy Titanium Dichloride Titanium Trichloride Titanium Triflouride Titanium Dioxide truncated light-harvesting Chi antenna... 

Metal hydride alloys for distributed storage and transportation Development of hydrogen absorbing alloys for - automobiles - compact stationary storage tank - large-scale storage system Development of alloys for commercial use... 

Fig. 5.35 Nyquist plot of the impedance response of bare and cobalt-coated metal hydride alloy at different charge-discharge cycles [76].

For pyrophoric materials, oxidation of the compound by oxygen or moisture in air proceeds so rapidly that ignition occurs. Many finely divided metals are pyrophoric, and their degree of reactivity depends on particle size, as well as factors such as the presence of moisture and the thermodynamics of metal oxide or metal nitride formation. Many other reducing agents, such as metal hydrides, alloys of reactive metals, low-valent metal salts, and iron sulfides, are also pyrophoric. 

Nickel metal hydride (Ni-MH) batteries have application in hybrid electric vehicles, portable electronic devices such as cameras, shavers, toothbrushes, etc. They offer a higher energy option than Ni-Cd batteries with the hydrogenabsorbing metal hydride alloy (MH) replacing the cadmium electrode in Ni-Cd cell construction. Like Ni-Cd, the Ni-MH also shows the memory effect on repetitive cycle regimes. The nickel metal hydride battery was introduced commercially in 1989. The technology is based on the development of rare earth alloys with nickel that have the ability to reversibly absorb and desorb hydrogen. The... 

NH3 also can be formed catalytically from traces of N2 in H2 when AB5 metal hydride alloys are used for hydrogen storage [88,89]. 

EEI has used both commercially sintered silver powder with 1-mm-thick electrodes and sintered silver powder with in-house electrodes made from an ABj-type metal-hydride alloy (also known as lanthanum-nickel alloy) using rare earth material for initial laboratory cell test evaluations. Introduction of rare earth material improves the oxidation resistance during the alloy manufacturing process. The ABj-type metal-hydride alloy should be widely used in sealed Ni-MH batteries. The use of rare earth metal lanthanum will provide improved electrical performance, enhanced reliability, and ultra-high longevity for the sealed Ni-MH and Ag-MH battery systems. 

TABLE 29.2 Comparison of Metal Hydride Alloys—Electrochemical Equivalents... 

Another aspect of performance is the effect of storage at temperature on life (discussed later). Extended storage over temperatures of about 45°C can reduce life due to degradation of the separator, oxidation and corrosion of the metal hydride alloy, and disruption of the cobalt conductive network in the positive electrode. Each of these mechanisms is highly dependent on the manufacturer s choices of the materials. 

Design factors which the NiMH manufacturer must consider for good shelf life are the oxidation and corrosion resistance of the metal hydride alloy, the amount of precharge on the metal hydride electrode, the nickel hydroxide active material formula, and the quality of the cobalt conductive network in the positive electrode. 

Intensive development of NiMH battery technology is underway in many places worldwide. Widespread activity has been reported on magnesium-based metal hydride alloys for capacity and cost advantages, evaluation of bipolar NiMH designs, satellite NiMH battery development, and a myriad of technical goals too lengthy to list here. However, the most intensive NiMH development at this time involves efforts to raise specific power to new levels and to reduce cost. 

Stoichiometry in LaNis-based metal hydride alloys... 

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