Structures and electrochemical performances of as-spun RE-Mg-Ni-Co-Al alloys applied to Ni-MH battery

doi:10.1016/j.jmst.2017.06.016

Abstract

Abstract:

The La-Mg-Ni-Co-Al-based AB₂-type La_0.8-_xCe_0.2Y_xMgNi_3.4Co_0.4Al_0.1 (x = 0, 0.05, 0.1, 0.15, 0.2) alloys were prepared by melt spinning. The effects of Y content on the structures and electrochemical hydrogen storage characters were thoroughly studied. The structures of the experimental samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is shown that there are a main phase LaMgNi₄ and a second phase LaNi₅ in the experimental samples. The variation of Y content incurs obvious changes of the phase abundance without changing phase composition. Namely, with the increase of Y content, the LaMgNi₄ phase increases and LaNi₅ phase decreases. Furthermore, melt spinning and the replacement of Y for La also lead to the grains refinement of the alloy. The electrochemical tests display that the as-spun alloys possess excellent activation properties, and obtain the maximums of discharge capacity at the first cycling. The replacement of Y for La can visibly facilitate the discharge potential characteristics, however,diminish the discharge capacity. The electrochemical kinetics, involving in the high rate discharge ability (HRD), hydrogen diffusion coefficient (D), limiting current density (I_L) and charge transfer rate, increases firstly and then decreases with the increase of Y content. The cyclic stability is greatly improved by melt spinning and the replacement of Y for La, which is derived from the improvement of the anti-corrosion, oxidation-resistance and the anti-pulverization abilities.

Key words: AB₂-type alloy, Melt spinning, Replacement of Y for La, Electrochemical characteristic

Yanghuan Zhang, Songsong Cui, Yaqin Li, Hongwei Shang, Yan Qi, Dongliang Zhao. Structures and electrochemical performances of as-spun RE-Mg-Ni-Co-Al alloys applied to Ni-MH battery[J]. J. Mater. Sci. Technol., 2018, 34(2): 370-378.

Figures/Tables 13

Fig. 1. XRD curves of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys: (a) As-spun (2 m/s), (b) As-spun (20 m/s), (c) Rietveld refinement on the XRD patterns of the as-spun (2 m/s) Y0 alloy.

Table 1 Lattice constants and abundances of LaMgNi4 and LaNi5 phases.

States	Alloys	Phases	Lattice constants (nm)		Cell volume	Phase abundance
			a	c	(nm³)	(wt%)
As-spun (2 m/s)	Y₀	LaMgNi₄	0.7178	-	0.3698	76.3
	Y₀	LaNi₅	0.5069	0.4025	0.0896	23.7
	Y_0.05	LaMgNi₄	0.7173	-	0.3691	77.1
	Y_0.05	LaNi₅	0.5062	0.4024	0.0893	22.9
	Y_0.1	LaMgNi₄	0.7166	-	0.3680	78.2
	Y_0.1	LaNi₅	0.5058	0.4022	0.0891	21.8
	Y_0.15	LaMgNi₄	0.7153	-	0.3660	78.7
	Y_0.15	LaNi₅	0.5053	0.4017	0.0888	21.3
	Y_0.2	LaMgNi₄	0.7148	-	0.3652	79.4
	Y_0.2	LaNi₅	0.5049	0.4013	0.0886	21.6
As-spun (20 m/s)	Y₀	LaMgNi₄	0.7188	-	0.3714	78.6
	Y₀	LaNi₅	0.5081	0.4029	0.0901	21.4
	Y_0.05	LaMgNi₄	0.7182	-	0.3705	79.2
	Y_0.05	LaNi₅	0.5077	0.4028	0.0899	20.8
	Y_0.1	LaMgNi₄	0.7179	-	0.3700	79.8
	Y_0.1	LaNi₅	0.5071	0.4025	0.0896	20.2
	Y_0.15	LaMgNi₄	0.7173	-	0.3691	80.6
	Y_0.15	LaNi₅	0.5067	0.4023	0.0894	19.4
	Y_0.2	LaMgNi₄	0.7165	-	0.3678	81.3
	Y_0.2	LaNi₅	0.5062	0.4021	0.0892	18.7

Fig. 2. SEM morphologies of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys (a), (b) and (c) Y0, Y0.1 and Y0.2 alloys spun at 2 m/s; (d), (e) and (f) Y0, Y0.1 and Y0.2 alloys spun at 20 m/s.

Fig. 3. Evolution of the discharge capacity of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys with cyclic number: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 4. Discharge potential curves of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 5. Evolution of the HRD of the as-spun La0.8-xCe0.2YxMgNi3.4 Co0.4Al0.1 (x = 0-0.2) alloys with current density: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 6. Electrochemical impedance spectra (EIS) of the as-spun (10 m/s) La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys and the equivalent circuit.

Fig. 7. Electrochemical impedance spectra (EIS) of the as-spun Y0.1 alloys at various temperatures: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 8. Evolutions of the activation enthalpy DrH* values of the as-spun (2 and 20 m/s) La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys with Y content.

Fig. 9. Semilogarithmic curves of anodic current vs. time responses of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 10. Potentiodynamic polarization curves of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 11. Evolution of the capacity retaining rates (Sn) of the as-spun La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1 (x = 0-0.2) alloys with cyclic number: (a) As-spun (2 m/s), (b) As-spun (20 m/s).

Fig. 12. SEM morphologies together with typical XRD pattern of the as-spun alloys before and after electrochemical cycle: (a) As-spun (2 m/s) Y0 alloy before cycling; (b) and (c) As-spun (2 m/s) Y0 and Y0.1 alloys after cycling; (d) XRD of As-spun (10 m/s) Y0 alloy after cycling.

References

[1]	D. Mori, K. Hirose, Int. J. Hydrogen Energy 34 (2009) 4569-4574.
[2]	R. Lan, T.S. Irvine John, S.W. Tao, Int. J. Hydrogen Energy 37 (2012) 1482-1497.
[3]	R.F. Li, P.Z. Xu, Y.M. Zhao, J. Wan, X.F. Liu, R.H. Yu, J. Power Sources 270(2014)21-27.
[4]	K. Kadir, T. Sakai, I. Uehara, J. Alloys Compd. 302(2000) 112-117.
[5]	K. Kadir, D. Noreus, I. Yamashita, J. Alloys Compd. 345(2002) 140-143.
[6]	Z.M. Wang, H.Y. Zhou, Z.F. Gu, G. Cheng, A.B. Yu, J. Alloys Compd. 377(2004)L7-L9.
[7]	L. Guénée, V. Favre-Nicolin, K. Yvon, J. Alloys Compd. 348(2003) 129-137.
[8]	Y.F. Liu, H.G. Pan, M.X. Gao, Q.D. Wang, J. Mater.Chem. 21(2011) 4743-4755.
[9]	Y.F. Liu, Y.H. Cao, L. Huang, M.X. Gao, H.G. Pan, J. Alloys Compd. 509(2011)675-686.
[10]	X. Tian, G.H. Yun, H.Y. Wang, T. Shang, Z.Q. Yao, W. Wei, X.X. Liang, Int. J.Hydrogen Energy 39 (2014) 8474-8481.
[11]	A. Teresiak, M. Uhlemann, J. Thomas, J. Eckert, A. Gebert, J. Alloys Compd. 582(2014) 647-658.
[12]	T. Yang, T.T. Zhai, Z.M. Yuan, W.G. Bu, S. Xu, Y.H. Zhang, J. Alloys Compd. 617(2014) 29-33.
[13]	T.T. Zhai, T. Yang, Z.M. Yuan, Y.H. Zhang, Int. J. Hydrogen Energy 39 (2014)14282-14287.
[14]	T. Yang, Z.M. Yuan, W.G. Bu, Z.C. Jia, Y. Qi, Y.H. Zhang, Mater. Des. 93(2016)46-52.
[15]	Y.H. Zhang, Y. Cai, C. Zhao, T.T. Zhai, G.F. Zhang, D.L. Zhao, Int. J. HydrogenEnergy 37 (2012)14590-14597.
[16]	A. Teresiak, A. Gebert, M. Savyak, M. Uhlemann, Ch. Mickel, N.Mattern, J.Alloys Compd. 398(2005) 156-164.
[17]	Y.H. Zhang, Y.Q. Li, H.W. Shang, Z.M. Yuan, T. Yang, S.H. Guo, J. Solid StateElectrochem. 21(2017) 1015-1025.
[18]	W.H. Lai, C.Z. Yu, Chin. Battery 26 (1996) 189-191.
[19]	Y. Wu, W. Hana, S.X. Zhou, M.V. Lototsky, J.K. Solberg, V.A. Yartys, J.AlloysCompd. 466(2008) 176-181.
[20]	H.G. Pan, N. Chen, M.X. Gao, R. Li, Y.Q. Lei, Q.D. Wang, J. Alloys Compd. 397(2005) 306-312.
[21]	X.Y. Zhao, Y. Ding, L.Q. Ma, L.Y. Wang, M. Yang, X.D. Shen, Int. J. HydrogenEnergy 33 (2008) 6727-6733.
[22]	N. Kuriyama, T. Sakai, H. Miyamura, I. Uehara, H. Ishikawa, T. Iwasaki, J.AlloysCompd. 202(1993) 183-197.
[23]	H.L. Ding, H.M. Han, Y. Liu, J.S. Hao, Y. Li, J.W. Zhang, Int. J. Hydrogen Energy34 (2009) 9402-9408.
[24]	S. Ruggeri, L. Roué, J. Huot, R. Schulz, L. Aymard, J.M. Tarascon, J. PowerSources 112 (2002) 547-556.
[25]	Y.H. Zhang, B.W. Li, H.P. Ren, Y. Cai, X.P. Dong, X.L. Wang, J. Alloys Compd. 458(2008) 340-345.
[26]	G. Zhang, B.N. Popov, R.E. White, J. Electrochem.Soc. 142(1995)2695-2698.
[27]	N. Cui, J.L. Luo, Int. J. Hydrogen Energy 24 (1999) 37-42.
[28]	N. Kuriyama, T. Sakai, H. Miyamura, I. Uehara, H. Ishikawa, T. Iwasaki, J.AlloysCompd. 202(1993) 183-197.