کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7712350 1497422 2016 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phase structure and cycling stability of A2B7 superlattice La0.60Sm0.15Mg0.25Ni3.4 metal hydride alloy
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Phase structure and cycling stability of A2B7 superlattice La0.60Sm0.15Mg0.25Ni3.4 metal hydride alloy
چکیده انگلیسی
Improvement in cycling stability is a key issue for La-Mg-Ni-based alloys to be widely applied as anode electrode materials of nickel metal hydride batteries. In this paper, we report the phase structure and melioration of cycling stability of a Sm-containing A2B7-type La-Mg-Ni-based alloy. Sm element promotes the Gd2Co7-type phase formation with increasing annealing period, which the Ce5Co19-, CaCu5- and MgCu4Sn-type phases in as-cast La0.60Sm0.15Mg0.25Ni3.4 alloy are successively eliminated as the annealing time increases from 6 to 24 h at 950 °C and forms a single A2B7-type alloy with coexistence of 73.2 wt.% Gd2Co7- and 26.8 wt.% Ce2Ni7-type phases. The single A2B7-type La0.60Sm0.15Mg0.25Ni3.4 alloy is superior in discharge capacity (382 mAh g−1) and high rate dischargeability (40% at a 1500 mA g−1 discharge current density). Especially, the cycling stability of the alloy is enhanced to 87.7% at the 100th cycle. The improved cycling stability of the single A2B7-type alloy is mainly attributed to its slower growth of inner strain during charging/discharging, which improves anti-pulverization/amorphization ability, and drops oxidation degree of the alloy. Therefore, Sm is a positive element in improvement of the cycling stability property of the La-Mg-Ni-based alloys.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Hydrogen Energy - Volume 41, Issue 3, 21 January 2016, Pages 1791-1800
نویسندگان
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