汽车用La0.79Mg0.21Ni3.95储氢合金的制备与电化学性能研究

doi:10.19964/j.issn.1006-4990.2020-0534

摘要/Abstract

摘要：

为开发出高能量密度镍氢电池负极材料,采用真空感应熔炼的方法制备了La_0.79Mg_0.21Ni_3.95储氢合金,对比分析了铸态和退火态储氢合金的物相组成、显微形貌和电化学性能。结果表明,铸态和800 ℃/24 h退火态La_0.79Mg_0.21Ni_3.95储氢合金中都只含有LaNi₅和（La,Mg）₂Ni₇相;升高温度至900 ℃及以上时,储氢合金中形成了不同含量的（La,Mg）₅Ni₁₉和（La,Mg）₆Ni₂₄相。900 ℃/24 h退火态储氢合金的可逆吸放氢性能要高于950 ℃/48 h退火态储氢合金。铸态和退火态储氢合金都在前3周循环过程中到达了最大放电比容量,950 ℃/48 h退火态储氢合金中主要为（La,Mg）₆Ni₂₄相,其具有较高的循环稳定性。铸态和退火态La_0.79Mg_0.21Ni_3.95储氢合金具有良好的电化学活化性能,高倍率放电性能（HRD₁₅₀₀）从高至低的顺序依次为950 ℃/48 h、950 ℃/24 h、900 ℃/24 h、 800 ℃/24 h、铸态;储氢合金的HRD₁₅₀₀与氢扩散速率（D）和交换电流密度（I₀）的变化趋势相同,950 ℃/48 h退火态储氢合金具有最大的HRD₁₅₀₀,这主要与合金电极中含有61.8%（质量分数）的（La,Mg）₆Ni₂₄相、具有较高的D和I₀有关。

关键词: La_0.79Mg_0.21Ni_3.95储氢合金, 退火温度, 退火时间, 显微形貌, 电化学性能

Abstract:

In order to develop cathode materials for Ni-MH batteries with high energy density,La_0.79Mg_0.21Ni_3.95 hydrogen storage alloy was prepared by vacuum induction melting,and the phase composition,microstructure and electrochemical properties of as cast and annealed hydrogen storage alloys were compared and analyzed.The results showed that there were only LaNi₅ and（La,Mg）₂Ni₇ phases in as cast and 800 ℃/24 h annealed La_0.79Mg_0.21Ni_3.95 hydrogen storage alloys.When the tem-perature was raised to 900 ℃ or above,different contents of（La,Mg）₅Ni₁₉ phase and（La,Mg）₆Ni₂₄ phase were formed in the hydrogen storage alloy.The reversible hydrogen absorption and desorption performance of 900 ℃/24 h annealed hydrogen storage alloy was higher than that of 950 ℃/48 h annealed hydrogen storage alloy.The maximum discharge capacity of as cast and annealed hydrogen storage alloys reached the maximum in the first three cycles,and the hydrogen storage alloy annealed at 950 ℃/48 h mainly consisted of（La,Mg）₆Ni₂₄ phase,which had high cycle stability.As cast and annealed La_0.79Mg_0.21Ni_3.95 hy-drogen storage alloys had good electrochemical activation properties.The order of HRD₁₅₀₀ from high to low was: 950 ℃/48 h>950 ℃/24 h>900 ℃/24 h>800 ℃/24 h>as cast,the results showed that the HRD₁₅₀₀ of hydrogen storage alloy had the same trend with that of hydrogen diffusion rate（D） and exchange current density（I₀）.The maximum HRD₁₅₀₀ of hydrogen storage alloy annealed at 950 ℃/48 h was mainly due to the fact that the alloy electrode contained 61.8% of（La,Mg）₆Ni₂₄ phase and had higher D and I₀.

Key words: La_0.79Mg_0.21Ni_3.95 hydrogen storage alloy, annealing temperature, annealing time, microstructure, electrochemical property

中图分类号:

TM912
TB33

范庆科,孟庆华. 汽车用La_0.79Mg_0.21Ni_3.95储氢合金的制备与电化学性能研究[J]. 无机盐工业, 2022, 54(3): 71-76.

FAN Qingke,MENG Qinghua. Study on preparation and electrochemical properties of La_0.79Mg_0.21Ni_3.95 hydrogen storage alloy for vehicles[J]. Inorganic Chemicals Industry, 2022, 54(3): 71-76.

图/表 12

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参考文献 16

[1]	李通, 史云斌, 刘庆彬, 等. 硒掺杂改性新能源汽车锂电池正极材料的结构与电化学性能[J]. 无机盐工业, 2020, 52(2):17-22.
[2]	杨敬江, 罗峰, 童芳. 新能源汽车用储氢合金的制备与电化学性能研究[J]. 铸造技术, 2018, 39(12):2673-2677.
[3]	周娟英, 赵建有, 王露峰, 等. 新能源车用电池负极材料的开发与性能[J]. 实验室研究与探索, 2020, 39(7):48-52.
[4]	李家丞, 徐凡, 游经纬, 等. La_0.7Mg_0.3-_xLi_xNi_2.8Co_0.5(x=0.00,0.05,0.10,0.15)合金制备与电化学性能的研究[J]. 材料导报, 2016, 30(14):29-33.
[5]	唐成颖, 潘文超, 覃钺迪, 等. La_0.7Mg_0.3Ni_2.8Co_(0.5-_x)Fe_x系列合金的制备及其储氢性能[J]. 中国有色金属学报, 2011(6):181-187.
[6]	黄显吞, 卢照, 卿培林, 等. La_0.7-_xPr_xZr_0.1Mg_0.2Ni_2.75Co_0.45Fe_0.1Al_0.2(x=0.00,0.05,0.10,0.15,0.20)合金储氢及电化学性能研究[J]. 材料导报, 2016, 30(6):33-37.
[7]	LIU Z P, YANG S Q, LI Y, et al. Phase structure and electrochemi-cal performances of Co-free La-Mg-Ni-based alloys with Nd/Sm partial substitution for La[J]. Rare Metals, 2014, 33(6):674-680.
[8]	邓安强, 罗永春, 王浩, 等. 退火处理对A₂B₇型La_0.63Pr_0.1Nd_0.1Y_0.6Sm_0.1Gd_0.1Mg_0.17Ni_3.1Co_0.3Al_0.1储氢合金相结构和电化学性能的影响[J]. 材料导报, 2018, 32(15):2565-2570.
[9]	ZHANG L, CAO S, LI Y, et al. Effect of Nd on subunits structure and electrochemical properties of super-stacking PuNi₃-type La-Mg-Ni-based alloys[J]. Journal of the Electrochemical Society, 2015, 162(10):2218-2226.
[10]	MA P P, ZHU B, LEI N, et al. Effect of Sr substitution on structure and electrochemical properties of perovskite-type LaMn_0.9Ni_0.1O₃ nanofibers[J]. Materials Letters, 2019, 252(1):23-26.
[11]	LIU J, HAN S, LI Y, et al. Effect of Al incorporation on the degradation in discharge capacity and electrochemical kinetics of La-Mg-Ni-based alloys with A₂B₇-type super-stacking structure[J]. Journal of Alloys and Compounds, 2015, 619:778-787.
[12]	LI R, YU R, LIU X, et al. Study on the phase structures and electro-chemical performances of La_0.6Gd_0.2Mg_0.2Ni_3.15-_xCo_0.25Al_0.1Mn_x(x=0~0.3) alloys as negative electrode material for nickel/metal hydride batteries[J]. Electrochimica Acta, 2015, 158:89-95.
[13]	李金, 王利, 闫慧忠, 等. 铸造方法对LaY₂Ni_9.7Al_0.3Mn_0.5储氢合金性能的影响[J]. 电池, 2020, 50(3):242-244.
[14]	闫静, 田晓, 姚占全, 等. 球磨AB₅型储氢合金对BH₄^-的催化性能与其电化学性能的相关性研究[J]. 稀土, 2020, 41(3):44-52.
[15]	赵鑫, 可丹丹, 吉力强, 等. Sm对La_0.5Nd_(0.35-_x)Sm_xMg_0.15Ni_3.5合金晶体结构和储氢性能的影响[J]. 储能科学与技术, 2020, 9(4):1066-1073.
[16]	邓安强, 罗永春, 夏元华, 等. 退火处理对新型无镁Y_0.7La_0.3Ni_3.25Al_0.1Mn_0.15储氢合金结构和电化学性能的影响[J]. 高等学校化学学报, 2020, 41(1):145-154.

序号	退火温度/℃	退火时间/h	冷却方式
1	800、900	24	随炉冷却
2	950	24、48、60	随炉冷却
3	975	24	随炉冷却

试样	相组成	晶胞参数		w（相）/ %
试样	相组成	a/nm	b/nm	w（相）/ %
铸态	LaNi₅	0.503 4	0.399 5	50.9
铸态	（La,Mg）₂Ni₇	0.503 2	3.615 1	49.1
800 ℃/24 h	LaNi₅	0.503 7	0.400 6	45.1
800 ℃/24 h	（La,Mg）₂Ni₇	0.502 6	3.625 4	54.9
900 ℃/24 h	LaNi₅	0.504 1	0.400 0	35.2
900 ℃/24 h	（La,Mg）₅Ni₁₉	0.503 1	4.817 5	64.8
950 ℃/24 h	LaNi₅	0.503 0	0.4010	22.8
	（La,Mg）₅Ni₁₉	0.503 5	4.814 8	43.6
	（La,Mg）₆Ni₂₄	0.503 5	5.979 1	33.6
950 ℃/48 h	LaNi₅	0.502 2	0.400 3	20.1
	（La,Mg）₅Ni₁₉	0.503 6	4.814 6	18.1
	（La,Mg）₆Ni₂₄	0.496 4	6.108 8	61.8
950 ℃/60 h	LaNi₅	0.503 4	0.401 7	49.4
	（La,Mg）₂Ni₇	0.505 3	2.527 3	28.3
	（La,Mg）₆Ni₂₄	0.504 0	6.014 7	22.6
975 ℃/24 h	LaNi₅	0.499 6	0.402 8	68.1
	（La,Mg）₂Ni₇	0.499 8	2.528 3	22.1
	（La,Mg）₅Ni₁₉	0.512 1	3.207 0	10.1

试样	区域	相组成	质量分数/%			x（La）: x（Mg）:x（Ni）
试样	区域	相组成	La	Mg	Ni	x（La）: x（Mg）:x（Ni）
铸态	α	LaNi₅	33.74	—	66.26	1:0:4.73
铸态	β	（La,Mg）₂Ni₇	33.43	1.88	64.69	0.76:0.24:3.49
900 ℃/24 h	α	LaNi₅	33.68	—	66.32	1:0:4.69
900 ℃/24 h	γ	（La,Mg）₅Ni₁₉	33.49	1.26	65.25	0.81:0.17:3.80
950 ℃/24 h	α	LaNi₅	33.67	—	66.33	1:0:4.65
	γ	（La,Mg）₅Ni₁₉	33.35	1.20	65.45	0.81:0.18:3.79
	δ	（La,Mg）₆Ni₂₄	33.34	1.07	65.59	0.85:0.15:3.99
950 ℃/48 h	α	LaNi₅	33.64	—	66.36	1:0:4.76
	γ	（La,Mg）₅Ni₁₉	33.84	1.20	64.96	0.83:0.17:3.91
	δ	（La,Mg）₆Ni₂₄	33.65	0.80	65.55	0.87:0.13:4.13
950 ℃/60 h	α	LaNi₅	33.39	—	66.61	1:0:4.82
	δ	（La,Mg）₆Ni₂₄	33.21	0.89	65.90	0.86:0.12:4.12
	ε	（La,Mg）₂Ni₇	33.88	1.59	64.53	0.75:0.20:3.63
975 ℃/24 h	α	LaNi₅	32.64	—	67.36	1:0:4.90
	ε	（La,Mg）₂Ni₇	34.23	1.60	64.98	0.79:0.21:3.65
	η	（La,Mg）₅Ni₁₉	34.17	1.00	64.83	0.84:0.16:3.90

试样	C_max/ （mA·h·g^-1）	S₁₀₀/ %	HRD₁₅₀₀/ %	D/ （10^-11 cm²·s^-1）	I₀/ （mA·g^-1）
铸态	343	73.7	47.1	1.16	280.9
800 ℃/24 h	367	74.4	52.5	1.61	291.6
900 ℃/24 h	358	77.2	56.0	1.89	314.0
950 ℃/24 h	359	76.1	63.2	2.29	334.7
950 ℃/48 h	355	81.3	69.1	2.56	361.4

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