摘要
用真空电弧熔炼方法制备了Zr1-xScxMn0.6V0.2Ni1.2Co0.1(x=0～1)AB2型储氢合金,研究了Sc元素替代Zr对合金的微观组织结构、气态储氢及电化学性能的影响。研究结果表明,Zr1-xScxMn0.6V0.2Ni1.2Co0.1合金主要是由FCC型C15相、CsCl型结构的(ScZr)Ni相和少量的Ni10Zr7相组成,随Sc含量的增加,C15相丰度逐渐减小,(ScZr)Ni相丰度逐渐增加,当x=0.2时Ni10Zr7相基本消失;Sc元素对合金的首次气态吸氢动力学行为影响较大,随Sc含量的增加,合金吸氢动力学性能逐渐变缓,但吸氢容量逐渐提高,直至达x=1.0时的最大吸氢量1.87%;Sc元素对合金吸氢PCT曲线平衡氢压的影响规律不明显,随Sc含量增加,合金氢化物的形成焓ΔH从-26.66 kJ.mol-1逐渐减小到-8.14 kJ.mol-1。Sc元素的加入可明显改善合金电极的活化性能,提高放电容量,随Sc含量的增加,合金电极最大放电容量从x=0时的350.3 mAh.g-1增加到x=1时的429.8 mAh.g-1,呈先减小后增大的趋势,但电极容量的保持率S100随Sc含量增加而快速下降。
The Zr1-xScxMn0.6V0.2Ni1.2Co0.1（x=0~1） AB2-type hydrogen storage alloys were prepared by arc melting.The microstructure,gaseous hydrogen storage and electrochemical properties of Zr1-xScxMn0.6V0.2Ni1.2Co0.1（x=0~1） were investigated.The results showed that the AB2 alloys mainly consisted of FCC-type C15 phase structure,BCC-type（ScZr）Ni phase structure and minor Ni10Zr7 phase.With increasing the content of Sc,the phase abundance of C15 decreased and that of（ScZr）Ni phase gradually increased,and the Ni10Zr7 phase disappeared when x rose to 0.2.The addition of Sc had a significant effect on the kinetics of the first time hydrogen absorption behavior.As Sc content increasing,the hydrogen absorption kinetics of the alloys slowed down,however,hydrogen absorption capacity gradually increased to 1.87%（x=1.0）,the formation enthalpy of hydride was significantly reduced from-26.66 to-8.14 kJ · mol-1.With increasing the content of Sc,the discharge capacity of the alloys first decreased from 350.3 mAh · g-1（x=0） to 293.2 mAh · g-1（x=0.3） then increased to 429.8 mAh · g-1（x=1.0）,but the capacity retention rate of the alloys were gradually reduced.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2013年第4期442-449,共8页
Journal of the Chinese Society of Rare Earths
