动力型贮氢合金的研究

Study on High-Rate Dischargeability Hydrogen Storage Alloy

摘要:

研制了5个LaNi5型贮氢合金试样，分别对5种合金试样电极的电化学放电容量、高倍率充放电和宽温度范围内充放电性能、循环稳定性及其相结构进行了测试和分析。结果表明：Sn及Si的搀杂增加了合金的非化学计量比，稳定了合金的循环稳定性并改善了合金的高倍率充放性能；合金样(Ml0．90Nd0.10)Ni3.60Co0.50Mn0.40Al0.18Si0.42的容量较高，5C充电效率大于95％，5C放电效率大于90％，400次充放循环后容量保持率大于70％；所设计合金晶型均为CaCu5相，充放电循环后合金主相仍是CaCu5相，同时发生氧化和粉化现象。

Abstract:

Five LaNi5-type hydrogen storage alloys were prepared. Their electrodes?discharge capacity,high rate charge-discharge ability, temperature effect,crystal structure and cycling stability were investigated. The XRD results indicated that alloys examined in this work seem to be of single phase with the hexagonal CaCu5-type crystal structure. After 400 charge-discharge cycles, the same crystal structure remained, for some of oxides, for instance, Mm(OH)3 and La(OH)3;The composition of stannum or silicon stabilizes the cycle life and improves the high rate charge-discharge abilities of their electrodes;The electrochemical capacity of sample (Ml0.90Nd0.10)Ni3.60Co0.50Mn0.40Al0.18Si0.42 is above 290.72 mAh.g-1, with capacity preserving being above 70% after 400 charge-discharge cycles. Its 5C rate charge efficiency is higher than 95%,and 5C rate discharge efficiency higher than 90%. It also performs well at various operating temperatures.