CAJ | 학술논문

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。
용고빈감응용련법제비료희토계La0.8-xGd0.2MgxNi3.3Co0.3Al0.1（x=0～0.4）저경합금,병재아기화1273K하대주태합금진행퇴화처리,계통연구료용Mg부분체대La원소대합금미관조직화전화학성능적영향규률。합금상결구분석표명,합금조직주요유Pr5Co19형、PuNi3형、Ce2Ni7형화Ca-Cu5형상조성,수Mg함량증가,주상Pr5Co19형상함량선증가후감소,당x=0.15시체도최대치88.23%（질량분수）。전화학측시분석표명,수Mg함량적변화,합금전겁최대방전용량화용량보지솔균정선증가후감소적규률,당x=0.15시,합금전겁방전용량체도최대치377.9mAh/g,경100차충방전순배후기전겁용량적보지솔S100위90.2%,구유교호적전화학종합성능。
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.