Towards a viable hydrogen storage system for transportation application.
Hydrogen energy may provide the means to an environmentally friendly future. One of the problems related to its application for transportation is 'on-board' storage. Hydrogen storage in solids has long been recognized as one of the most practical approaches for this purpose. The H-capacity in interstitial hydrides of most metals and alloys is limited to below 2.5% by weight and this is unsatisfactory for on-board transportation applications. Magnesium hydride is an exception with hydrogen capacity of {approx}8.2 wt.%, however, its operating temperature, above 350 C, is too high for practical use. Sodium alanate (NaAlH{sub 4}) absorbs hydrogen up to 5.6 wt.% theoretically; however, its reaction kinetics and partial reversibility do not completely meet the new target for transportation application. Recently Chen et al. [1] reported that (Li{sub 3} N + 2H{sub 2} {leftrightarrow} LiNH{sub 2} + 2LiH) provides a storage material with a possible high capacity, up to 11.5 wt.%, although this material is still too stable to meet the operating pressure/temperature requirement. Here we report a new approach to destabilize lithium imide system by partial substitution of lithium by magnesium in the (LiNH{sub 2 + LiH {leftrightarrow} Li2NH + H2}) system with a minimal capacity loss. This Mg-substituted material can reversibly absorb 5.2 wt.% hydrogen at pressure of 30 bar at 200 C. This is a very promising material for on-board hydrogen storage applications. It is interesting to observe that the starting material (2LiNH{sub 2 + MgH2}) converts to (Mg(NH{sub 2}){sub 2} + 2LiH) after a desorption/re-absorption cycle.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 944393
- Report Number(s):
- SAND2004-4375C; TRN: US200902%%744
- Resource Relation:
- Conference: Proposed for presentation at the International Symposium on Metal Hydrogen Systems held September 5-10, 2004 in Kracow, Poland.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Catalyzed alanates for hydrogen storage
Final Report: DE- FC36-05GO15063, Fundamental Studies of Advanced High-Capacity, Reversible Metal Hydrides