摘要
作为第三代镍氢电池负极材料,La⁃Mg⁃Ni系储氢合金具有稳定的晶体结构、良好的吸放氢容量和电化学性能。但其较差的比容量和循环寿命对合金的进一步发展提出了挑战,元素替代被认为是提高La⁃Mg⁃Ni合金性能和循环寿命的重要有效方法之一。研究发现元素替代对La⁃Mg⁃Ni系合金晶体结构、储氢性能及电化学性能均会产生显著的影响。利用Mg或稀土元素替代La会导致合金的各晶体相晶胞体积减小;利用Mg、Ca和Co分别替代La和Ni会有效减少合金氢致非晶化的程度,从而显著提升合金的可逆吸氢量和电化学放电容量;利用Co、Mn、Fe、Al、Cu部分替代Ni会促使合金表面形成致密的钝化膜,有助于改善合金的电化学循环性能;利用Sn、Co、Cu部分替代Ni会提高合金电极的高倍率电流下的电化学放电容量。本文总结了La⁃Mg⁃Ni系合金中La(A位)和Ni(B位)元素进行元素替代的研究成果并展望了La⁃Mg⁃Ni系合金的发展前景,提出了有效改善La⁃Mg⁃Ni合金综合性能的措施和方法,期望研制出高容量和长寿命的镍氢电池负极材料。
Due to the stable super stacking structures,the La⁃Mg⁃Ni alloys show high hydrogen absorption capacity,good high rate discharge and activation performance.Therefore,La⁃Mg⁃Ni alloys are considered as the third⁃generation negative e⁃lectrode material of Ni⁃MH batteries.The partial replacement of La by Mg and rare earth elements will lead to the decrease of unit cell volume of the alloys;Mg,Ca and Co were used to increase the electrochemical discharge capacities by replacing La and Ni,respectively;The substitution of Co,Mn,Fe,Al and Cu for Ni is helpful to improve the cycling stabilities of the al⁃loys,due to the formation of dense passivation film on the surface of the alloys.Partial substitution of Sn,Co and Cu can im⁃prove the high⁃rate discharge capacity of alloy electrodes.This paper summarizes the substitutions effects on crystal structure,hydrogen storage and electrochemical properties in La⁃Mg⁃Ni alloys.The effective solutions are proposed to improve the dis⁃charge capacity and cycle life of La⁃Mg⁃Ni alloys as negative electrode materials for metal hydride batteries.
作者
齐颖
李宏鑫
万初斌
QI Ying;LI Hong-xin;WAN Chu-bin(Laboratory Service Guarantee Center Beijing,Beijing 101100,China;Department of Physics,University of Science and Technology Beijing,Beijing 100083,China)
出处
《稀土》
CAS
CSCD
北大核心
2023年第5期117-126,共10页
Chinese Rare Earths
基金
国家自然科学基金面上项目(11975043)。
关键词
储氢合金
La⁃Mg⁃Ni
元素替代
储氢性能
电化学性能
hydrogen storage alloys
La⁃Mg⁃Ni
element substitution
hydrogen storage performance
electrochemical performance
