Effect of beta-Li3N phase, Li2O addition and thermal treatment on the hydrogen sorption behavior of Li3N

LUISA FERNÁNDEZ ALBANESI; P. ARNEODO LAROCHETTE; F.C. GENNARI

JOURNAL OF POWER SOURCES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 197 p. 210 - 217

0378-7753

The hydriding of Li3N to LiNH2 is investigated to clarify the influence of the â-Li3N phase, the addition of Li2O and the thermal treatment of Li3N on the hydrogen storage properties of the Li–N–H system. Asmilled Li3N displays fast initial absorption that is attributed to the formation of â-Li3N nanograins, the increase of the surface area, and the presence of surface defects induced by mechanical milling. However, further hydrogen absorption is retarded in comparison with the as-received sample due to the presence of the â-Li3N phase formed during milling. Thus, commercial Li3N exhibits the highest hydrogen storage capacity in the first cycle in comparison with as-heated Li3N and as-milled samples. In the case of Li2O addition, no interaction with Li3N was detected. The addition of LiH to the commercial Li3N, as-milled Li3N and Li3N–Li2O influences only the stability of the samples under hydrogen cycling. The hydrogen absorption/desorption behavior is mainly controlled by the amount of beta-Li3N formed during milling, while at long times the microstructure has a minor effect.