球磨时间对La_(1.6)Y_(0.4)Mg_(16)Ni合金结构和电化学性能的影响  

Effects of ball milling time on structure and electrochemical properties of La_(1.6)Y_(0.4)Mg_(16)Ni alloy

作　　者：韦世强 蒋超超 张亮玖 周慧荣 李宽 WEI Shi-qiang;JIANG Chao-chao;ZHANG Liang-jiu;ZHOU Hui-rong;LI Kuan(Chinalco Guangxi Nonferrous Rare Earth Development Co.Ltd.,Nanning 530024,China;Guangxi Guosheng Rare Earth New Materials Co.Ltd.,Chongzuo 532200,Guangxi,China)

机构地区：[1]中铝广西有色稀土开发有限公司,南宁530024 [2]广西国盛稀土新材料有限公司,广西崇左532200

出　　处：《矿冶》2021年第5期97-102,共6页Mining And Metallurgy

基　　金：广西科技重大专项(桂科AA19254005,桂科AA18242022)。

摘　　要：先采用真空熔炼技术制备了La_(1.6)Y_(0.4)Mg_(16)Ni合金,然后通过将合金球磨得到了La_(1.6)Y_(0.4)Mg_(16)Ni合金粉末。采用扫描电子显微镜、X射线衍射仪、能谱仪对材料进行了表征。结果表明,经真空熔炼得到的合金为六方La_(1.6)Y_(0.4)Mg_(16)Ni,其空间群为P63/mmc(194)。六方La_(1.6)Y_(0.4)Mg_(16)Ni合金经球磨2 h以上,得到无规则形貌的非晶态合金粉末,其粒子尺寸随球磨时间的延长而减小。合金经10 h球磨后,得到尺寸分布较为均匀的椭球状合金粉末,其粒子尺寸在10~32μm。当将非晶态合金粉末用作储氢材料,经10 h球磨后得到的合金粉末比其他球磨时间的样品具有较高的倍率性能和放电比容量。例如,当电流密度从80 mA/g升高到1500 mA/g时,10 h球磨合金粉末的放电性能从100%仅下降至76.00%。此外,该合金粉末具有较高初始放电比容量(1050 mA·h/g)和长时循环稳定性,510次循环后仍能保持高达63%容量保持率。球磨10 h所得合金粉末的电化学性能显著高于其它球磨时间得到的合金粉末,归因于10 h球磨时间的合金粉末的粒度均匀,可为氢的电化学反应提供更多的活化位点。La_(1.6)Y_(0.4)Mg_(16)Ni alloy was prepared by vacuum melting technology,and then La_(1.6)Y_(0.4)Mg_(16)Ni alloy powder was obtained by ball milling.The materials were characterized by scanning electron microscope(SEM),X-ray diffractometer(XRD)and energy dispersive spectrometer(EDS).The results show that the alloy obtained by vacuum melting is hexagonal La_(1.6)Y_(0.4)Mg_(16)Ni with space group P63/mmc(194).After being ball milled for≥2 h,hexagonal La_(1.6)Y_(0.4)Mg_(16)Ni alloy was changed into amorphous alloy powder with irregular morphology,and its particle size decreases with the increase in milling time.After ball milling for 10 h,the amorphous alloy powder with ellipsoid morphology and uniform particle size distribution is obtained,and the particle size ranges from 10.2 to 31.8μm.When amorphous alloy powder was used as hydrogen storage material,the alloy powder obtained after ball milling for 10 behaved high rate performance and discharge specific capacity than those for other milling time.For example,when the current density increases from 80 mA/g to 1500 mA/g,the discharge performance of the alloy powder decreased from 100%to 78.09%.In addition,the alloy powder has a high initial discharge specific capacity(1050 mA·h/g).After 510 cycles,it can still maintain a capacity retention rate of up to 63%.The electrochemical properties of the alloy powder obtained for 10 h ball milling time are significantly higher than those obtained for other ball milling time,attributed to the uniform particle size of the alloy powder for 10 h milling time,which can provide more activation sites for the electrochemical reaction of hydrogen.

关 键 词：镧钇合金 稀土储氢 微观结构 电化学性能 

分 类 号：TG146.4[一般工业技术—材料科学与工程]