铸态和快淬态Mm(NiCoMnAl)_5B_x(x=0~0.2)贮氢合金的相结构与电化学性能

Microstructure and Electrochemical Characteristics of Mm(NiCoMnAl)_5B_x(x=0~0.2) Hydrogen Storage Alloys Prepared by Casting and Rapidly Quenching

摘要:

用铸造及快淬工艺制备了低钴AB5型Mm(NiCoMnAl)5Bx(x=0~0.2)贮氢合金,测试了合金的微观结构及电化学性能,研究了B含量及快淬工艺的变化对合金晶格常数、热力学参数、微观结构及电化学性能的影响。结果表明:合金的晶格常数、晶胞体积及标准生成焓均随B含量的增加而增大;在一定的淬速范围内,快淬处理可以提高合金的放电容量,但淬速超过某一临界淬速时,快淬合金的容量低于铸态合金;合金的循环寿命随淬速的增加而单调增加。

Abstract:

Low Co AB5-type Mm(NiCoMnAl)5Bx (x=0~0.2) hydrogen storage alloys were prepared by casting and rapidly quenching. The microstructures and electrochemical characteristics of the alloys were analyzed and measured. The effects of boron content and rapidly quenched technique on the lattice constants, thermodynamic parameters, microstructures and electrochemical properties of the alloys were investigated in detail. The obtained results show that the lattice constants, cell volume and standard enthalpy increased with the increase of boron content. When quenching rate is in a specifically range, the rapidly quenched treatment could enhance the discharge capacity of the alloys. When quenching rate is more than a certain critical value, The discharge capacity of the as-quenched alloy is less than that of the as-cast alloys. The cycle life of the alloys monotonously increased with the increase of quenching rate.