用高频感应熔炼法制备了稀土系La0.8-xGd0.2MgxNi3.3Co0.3Al0.1（x=0～0.4）储氢合金,并在氩气和1273K下对铸态合金进行退火处理,系统研究了用Mg部分替代La元素对合金微观组织和电化学性能的影响规律。合金相结构分析表明,合金组织主要由Pr5Co19型、PuNi3型、Ce2Ni7型和Ca-Cu5型相组成,随Mg含量增加,主相Pr5Co19型相含量先增加后减少,当x=0.15时达到最大值88.23%（质量分数）。电化学测试分析表明,随Mg含量的变化,合金电极最大放电容量和容量保持率均呈先增加后减小的规律,当x=0.15时,合金电极放电容量达到最大值377.9mAh/g,经100次充放电循环后其电极容量的保持率S100为90.2%,具有较好的电化学综合性能。
La0.8-xGd0.2MgxNi3.3Co0.3Al0.1（x = 0-0.4） hydrogen storage alloys were prepared by induction melting followed by annealing treatment for 16 hours at 1273K under high purity argon atmosphere.The effect of Mg on the microstructure and electrochemical properties of La0.8-xGd0.2MgxNi3.3Co0.3Al0.1（x = 0-0.4） were investigated systematically by means of X-ray diffraction（XRD）,electron probe micro-analysis（EPMA） and electrochemical measurements.The results showed that all the annealed alloys mainly consisted of Pr5Co19-type,PuNi3-type,Ce2Ni7-type and CaCu5-type phase.The main phase of Pr5Co19-type abundance first increased and then decreased with increasing Mg contents,and the maximum main phase abundance reached 88.23wt% when x was 0.15.The equilibrium pressures of hydrogen absorption rose gradually and became flatter when x increased.The lowest plateau pressure of the alloys was about 0.02MPa and the hydrogen storage capacity was 1.334wt% when x was 0.15.The electrochemical measurements showed that all the alloys had a superior activation capability and the discharge capacity of the alloys first increased and then decreased with the increase of Mg contents.Among the alloys study,the La0.65Gd0.2Mg0.15Ni3.3Co0.3Al0.1 alloy（x=0.15）possessed the best electrochemical properties,the maximum discharge capacity of the alloy reached 377.9 mAh/g and the discharge capacity retention rate S100 reached 90.2% after 100 charge-discharge cycles.
参考文献
| [1] | Liu Yongfeng;Cao Yanhui;Li Huang et al.[J].Journal of Alloys and Compounds,2011,509(03):675-686. |
| [2] | Yong Hui;Hu Feng;Zhang Yanghuan et al.Cast La0.75 Mg0.25 Ni3.3 Co0.2 Six(x= 0-0.2) electrode alloy electrochemical and dynamic performance[J].Journal of Functional Materials,2011,42(06):1104-1107. |
| [3] | Zhang Faliang;Luo Yongchun;Wang Dahui et al.[J].Journal of Alloys and Compounds,2007,439:181-188. |
| [4] | ZHANG Yang-huan,DONG Xiao-ping,WANG Guo-qing,GUO Shi-hai,REN Jiang-yuan,WANG Xin-lin.Effects of rapid quenching on microstructures and electrochemical properties of La0.7Mg0.3Ni2.55Co0.45Bx(x=0-0.2) hydrogen storage alloy[J].中国有色金属学会会刊（英文版）,2006(04):800-807. |
| [5] | Li F;Young K;Ouchi T et al.[J].Journal of Alloys and Compounds,2009,471:371-377. |
| [6] | Zhang Faliang;Luo Yongchun;Chen Jianping et al.[J].Journal of Power Sources,2005,150:247-254. |
| [7] | 田晓光,孙延伟,周东辉.化学镀镍对A2B7型贮氢合金电极电化学性能的影响[J].金属功能材料,2012(01):11-15. |
| [8] | 师彦春,张羊换,赵小龙,董小平,王新林.La-Mg-Ni系（AB3-3.5型）贮氢合金循环寿命改善途径[J].金属功能材料,2007(06):33-37. |
| [9] | Chen J;Takeshita H T;Tanaka H et al.[J].Journal of Alloys and Compounds,2000,302:304-313. |
| [10] | Denys R V;Yartys V A .[J].Journal of Alloys and Compounds,2011,509:S540-S548. |
| [11] | Nakamura J;Iwase K;Hayakawa H et al.[J].Journal of Physical Chemistry,2009,113:5853-5859. |
| [12] | ZHANG Yang-huan,DONG Xiao-ping,ZHAO Dong-liang,GUO Shi-hai,QI Yan,WANG Xin-lin.Influences of stoichiometric ratio B/A on structures and electrochemical behaviors of La0.75Mg0.25Ni3.5Mx (M=Ni, Co; x=0-0.6) hydrogen storage alloys[J].中国有色金属学会会刊（英文版）,2008(04):857-864. |
| [13] | Ferey A;Cuevas F;Latroche M et al.[J].Electrochimica Acta,2009,54:1710-1714. |
| [14] | 闫小龙,刘增彦,宋秀芹,柴玉俊,侯登录.LaNi3.8-xAlx（0≤x≤0.5）多相储氢合金的结构及电化学性能[J].中国稀土学报,2011(03):360-364. |
| [15] | 罗永春,贾秋荣,吴婷,康龙.稀土元素R对储氢合金（LaRMg）（NiCoAlZn）3.5相结构和电化学性能的影响[J].兰州理工大学学报,2009(04):1-6. |
| [16] | 马礼敦.近代X射线多晶体衍射[M].北京:化学工业出版社,2004:399-408. |
| [17] | 吴辉煌.电化学[M].北京:化学工业出版社,2004:121. |
| [18] | Si T Z;Pang G;Zhang Q A et al.[J].International Journal of Hydrogen Energy,2009,34(03):4833-4837. |
| [19] | Kadir K;Sakai T;Uehara I .[J].Journal of Alloys and Compounds,2000,302:112-117. |
| [20] | Murray J J;Post M L;Taylor J B .[J].Journal of the Less-Common Metals,1981,80(02):201-209. |
| [21] | 高志杰;康龙;罗永春.[J].高等学校化学学报(接收) |
| [22] | Denys, RV;Riabov, AB;Yartys, VA;Sato, M;Delaplane, RG .Mg substitution effect on the hydrogenation behaviour, thermodynamic and structural properties of the La2Ni7-H(D)(2) system[J].Journal of Solid State Chemistry,2008(4):812-821. |
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