IImprove hydrogen sorption kinetics of MgH2 by doping carbon-encapsulated iron-nickel nanoparticles

Journal Article · Mon Nov 30 00:00:00 EST 2020 · Journal of Alloys and Compounds

DOI:https://doi.org/10.1016/j.jallcom.2020.156035· OSTI ID:1668617

Ding, Zhenmin ^[1]; Fu, Yaoku ^[2]; Zhang, Lu ^[3]; Rodriguez Perez, Ismael A. ^[4]; Zhang, Hongming ^[2]; Wang, Wenfeng ^[2]; Li, Yuan ^[2]; Han, Shumin ^[5]

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1. Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineeri
2. Hebei Key Laboratory of Applied Chemistry, Yanshan University, Qinhuangdao, PR China
3. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Q
4. BATTELLE (PACIFIC NW LAB)
5. Yanshan University Qinhuangdao, China

Magnesium hydride (MgH2) with excellent hydrogen storage kinetics is important for the wide application of hydrogen energy. Herein, to accelerate the sorption kinetics of MgH2 and lower its dehydrogenation temperature, we design and prepare a carbon film coated dual transition metal alloy, the Fe0.64Ni0.36@C composite with a coreshell structure, and employ it as an additive to synthesize MgH2–Fe0.64Ni0.36@C system by ball-milling and hydriding combustion method. In contrast to pure MgH2, the initial hydrogen release temperature of the MgH2–Fe0.64Ni0.36@C composite lowers to 250°C from 480°C and the composite can absorb 5.18 wt% H2 within 20 min (150°C, 3 MPa H2). More importantly, the apparent activation energy of the dehydrogenation for decomposition of Fe0.64Ni0.36@C-doped MgH2 reduced from 162.8 ± 8.3 kJ/mol to 86.9 ± 4.6 kJ/mol. It is believed that the Fe@C and Mg2Ni/Mg2NiH4 formed on the surface of Mg/MgH2 act as intermediates of electron transfer between Mg2+ and H–, which synergistically enhanced the hydrogen absorption and desorption kinetics properties of the MgH2. Moreover, the MgH2 co-doped with the multiple in-situ formed active particles shows excellent cycling performance, indicative of potential application in practical hydrogen storage in the near future.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1668617
• Report Number(s): PNNL-SA-153605
• Journal Information: Journal of Alloys and Compounds, Vol. 843
• Country of Publication: United States
• Language: English