The Phase Structure and Electrochemical Properties of La₄MgNi₁₇M₂(M=Ni,Co,Mn) Hydrogen Storage Alloys

Abstract:

The phase structure and electrochemical properties of La4MgNi17M2(M=Ni,Co,Mn) alloys were investigated in detail. The XRD analysis revealed that the main phases in the alloys are LaNi5 and La4MgNi19 phases (Ce5Co19+Pr5Co19 structure). When the Ni element in the alloy was substituted by Mn or Co, the abundant of La4MgNi19 phase increased, and especially in the La4MgNi17Mn2 alloy, that increased to 70.7%. The electrochemical measurement showed that the activation of La4MgNi17M2(M=Ni,Co,Mn) alloy electrodes were improved, and it only needed 1-2 cycles.what’s more, with the elements substitution for Ni ,the maximum discharge capacity gradually increased to 386.10 mA·h/g (Co) and 375.18 mA·h/g (Mn), but high-rate dischargeability (HRD) decreased somewhat (Co, HRD900=86.2%). It is found that the HRD was mainly controlled by the electrocatalytic activity on the alloy electrode surface, and the decline of cyclic stability was due to the appearance of A5B19 type phase with larger hydrogen storage capacity, which lead to bigger volume expansion or intercrystalline stress, then easier pulverization during charging/discharging. In addition, the cyclic stability (S100) was improved with Co substitution, and worsened with Mn substitution, because Mn element was easily corroded and Co improved the ability of Corrosion resistance.

• Periodical: Advanced Materials Research (Volumes 875-877)
• Pages: 282-287
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.875-877.282
• Online since: February 2014
• Authors: Fan Song Wei, Fan Na Wei, Huan Huan Lu, Hong Fu Xiang
• Keywords: Crystal Structure, Electrochemical Property, Hydrogen Storage Alloy, La-Mg-Ni System

References

[1] LEI Y Q. New energy materials[M]. Tianjin: Tianjin University Press, 2000: 44-45.

[2] KADIR K, SAKAI T, UEHARA I. J Alloys Comp., 1999, 287: 264-270.

[3] KADIR K, SAKAI T, UEHARA I. J Alloys Comp., 2000, 302: 112-117.

[4] CHEN J, KURIYAMA N, TAKESHITA H T, TANAKA H, SAKA T and HARUTA M. Electrochem. Solid-State Lett., 2000, 3(6): 249-252.

[5] KOHNO T, YOSHIDA H, KAWASHIMA F, INDABA T, SAKAI I, YAMAMOTO M. J Alloys Comp., 2000, 311: L5-L7.

[6] PAN H G, LIU Y F, GAO M X, LEI Y Q, WANG Q D. J Electrochem Soc, 2003, 150: A565-A570.

[7] LIU Y F, PAN H G, GAO M X, LI R, LEI Y Q. J. Alloys Comp., 2005, 389(1-2): 281-289.

[8] LIAO B, LEI Y Q, CHEN L X, LU G L, PAN H G, WANG Q D. J Power Source, 2004, 129: 358-367.

[9] TANG R, LIU L Q, LIU Y N, YU G, ZHU J W, LIU X D. The Chinese Journal of Nonferrous Metals, 2005, 15(7): 1057−1061.

[10] LIAO B, LEI Y Q, CHEN L X, LÜ G L, PAN H G, WANG Q D. Journal of Alloys and Compounds, 2004, 376(1/2): 186−195.

[11] ZHANG X B, SUN D Z, YIN W Y, CHAI Y J, ZHAO M S. J Power Sources, 2006, 154: 290-297.

[12] ZHANG F L, LUO Y C, SUN K, KANG L, CHEN J H. Functional Materials, 2006, 37(2): 265−268.

[13] LIU Y F, PAN H G, GAO M X, ZHU Y F, LEI Y Q, WANG Q D. J Electrochem. Soc., 2004, 151(3): A374-A380.

[14] JIANG B J, WANG J, MU D B, CHEN S, WU B R, WU F. the Chinese Journal of Nonferrous Metals, 2008, 18 (11): 2036-(2043).

[15] LIU Y F, PAN H G, GAO M X, ZHU Y F, LEI Y Q. Transactions of Nonferrous Metals Society of China, 2003, 13: 25-28.

[16] ZHOU Z L, SONG Y Q, CUI S, LIN C G, GUO Z M, QU X H. Rare Metal Materials and Engineering, 2008, 37 (6)：964-969.

[17] ZHANG Y H, DONG X P, WANG G Q, GUO S H, REN J Y. the Chinese Journal of Nonferrous Metals, 2005, 15 (5): 705-710.

[18] ZHANG Y H, ZHAO D L, DONG X P, QI Y. Transactions of Nonferrous Metals Society of China, 2009, 19 (2): 364-371.

[19] PAN H G，MA J X，WANG C S，CHEN S A，WANG X H，CHENC P，WANG Q D. J Alloys Compd., 1999, 293-295: 648.