The Electronic and Electrochemical Properties of the LaNi_5-Based Alloys

• Authors: A. Szajek , A. Jezierski , M. Nowak , M. Jurczyk
• Languages of publication: EN

Abstracts

EN

Mechanical alloying was used to synthesize LaNi_5-type hydrogen storage materials. X-ray diffraction analysis showed that, after 30 h milling, the starting mixture of the elements was decomposed into an amorphous phase. Following the annealing in high purity argon at 700°C for 0.5 h, X-ray diffraction confirmed the formation of the CaCu_5-type structures. The nanocrystalline materials were used as negative electrodes for a Ni-MH_x battery. A partial substitution o Ni by Al or Mn in LaNi_{5-x}M_x alloy leads to an increase in discharge capacity. On the other hand, the alloying elements such as Al, Mn and Co greatly improved the cycle life of LaNi_5 material. For example, in the nanocrystalline LaNi_{3.75}Mn_{0.75}Al_{0.25}Co_{0.25} powder, discharge capacities of up to 258 mA h g^{-1} (at 40 mA g^{-1} discharge current) were measured. The band structure ab initio calculations showed that 3g sites are preferred by Al, Co, and Mn atoms in the unit cell.

Keywords

EN

71.20.-b; 81.20.Ev

Discipline

• 71.20.-b: Electron density of states and band structure of crystalline solids
• 81.20.Ev: Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2009
• Volume: 115
• Issue: 1
• Pages: 247-250

Dates

published

2009-01

Contributors

author

A. Szajek

• Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland.

author

A. Jezierski

• Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland.

author

M. Nowak

• Institute of Materials Science and Engineering, Poznań University of Technology, M. Skłodowska-Curie Sq. 5, 60-965 Poznań, Poland

author

M. Jurczyk

• Institute of Materials Science and Engineering, Poznań University of Technology, M. Skłodowska-Curie Sq. 5, 60-965 Poznań, Poland

References

• 1. T. Sakai, M. Matsuoka, C. Iwakura, in: Handbook on the Physics and Chemistry of Rare Earth, Vol. 21, Ed. K.A. Gschneider, Jr., L. Eyring, Elsevier Sci. B.V., Amsterdam 1995, Ch. 142, p. 135
• 2. M. Jurczyk, M. Nowak, in: Nanostructured Materials in Electrochemistry, Ed. Eftekhari Ali, Wiley, Weinheim 2008
• 3. L. Smardz, M. Jurczyk, K. Smardz, M. Nowak, M. Makowiecka, I. Okonska, Renewable Energy 33, 201 (2008)
• 4. Y. Nakamura, H. Nakamura, S. Fujitani, I. Yonezu, J. Alloys Comp. 210, 299 (1994)
• 5. J.J.G. Willems, K.H.J. Buschow, J. Less-Common Met. 129, 13 (1987)
• 6. L. Zaluski, A. Zaluska, J.O. Ström-Olsen, J. Alloys Comp. 253-254, 70 (1997)
• 7. K. Köpernik, H. Eschrig, Phys. Rev. B 59, 1743 (1999)
• 8. I. Opahle, K. Köpernik, H. Eschrig, Phys. Rev. B 60, 14035 (1999)
• 9. K. Köpernik, B. Velicky, R. Hayn, H. Eschrig, Phys. Rev. B 55, 5717 (1997)
• 10. P. Blöchl, O. Jepsen, O.K. Andersen, Phys. Rev. B 49, 16223 (1994)
• 11. J.P. Perdew, Y. Wang, Phys. Rev. B 45, 13244 (1992)
• 12. J.-M. Joubert, R. Érny, M. Latroche, A. Percheron-Guégan, K. Yvon, J. Appl. Crystallogr. 31, 327 (1998)

Identifiers

DOI

10.12693/APhysPolA.115.247