Study the Effects of Mechanical Activation on Li-N-H Systems With 1H and 6Li Solid-State NMR

Journal Article · Tue Jul 10 04:00:00 EDT 2007 · Journal of Power Sources, 170(2):419-424

DOI:https://doi.org/10.1016/j.jpowsour.2007.02.080· OSTI ID:917576

Lu, Chun; Hu, Jian Zhi; Kwak, Ja Hun; Yang, Z Gary; Ren, Ruiming; Markmaitree, Tippawan; Shaw, Leonard D

To gain insight into the effects of mechanical activation (MA) on the hydrogen desorption of the lithium amide (LiNH2) and lithium hydride (LiH) mixture, LiNH2 and LiH+LiNH2 were mechanically activated by high-energy ball milling. The formed products were studied with in situ 1H and 6Li nuclear magic angle spinning (MAS) magnetic resonance (NMR) spectroscopy from ambient temperature to 180 degrees C. Up-field chemical shift was observed in 6Li MAS NMR spectra with increased milling time, indicating that average local electronic structure around Li nuclei was modified during MA. 1H MAS NMR was used to dynamically probe ammonia release from the activated LiNH2 at temperature as low as 50 degrees C. In the case of activated LiH+LiNH2 mixtures, the 1H MAS NMR results implied that MA enhanced the dehydrogenation reaction of LiNH2+LiH=Li2NH+H2 and suppressed ammonia generation as well.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 917576
• Report Number(s): PNNL-SA-53592; EB4202000
• Journal Information: Journal of Power Sources, 170(2):419-424, Journal Name: Journal of Power Sources, 170(2):419-424 Journal Issue: 2 Vol. 170; ISSN JPSODZ; ISSN 0378-7753
• Country of Publication: United States
• Language: English

Related Subjects

1H NMR
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
6Li NMR
Lithium amide and hydride
AMIDES
CHEMICAL SHIFT
DEHYDROGENATION
ELECTRONIC STRUCTURE
Hydrogen storage
LITHIUM COMPOUNDS
LITHIUM HYDRIDES
MILLING
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
ammonia.
chemical shift