快淬工艺对低钴AB_5型贮氢合金电化学性能的影响

The effect of rapid quenching on the electrochemical performances of low-Co AB5-type hydrogen storage alloys

研究了快淬工艺对稀土基低钴AB5型LaxMm1-x(NiMnSiAlFe)4.7Co0.2(x=0、1)贮氢合金的电化学性能及其微观结构的影响。研究结果表明,快淬改善了两种合金的循环稳定性,其主要原因是快淬使合金的晶胞体积增大,且使合金的晶粒细化;快淬对La含量x=0合金的循环寿命的增加幅度尤其明显,主要是因为快淬使该合金的晶粒更为细小。La替代Mm使合金的放电容量提高,其原因是La替代Mm抑制了第二相Ce2Ni7相的形成,并使合金的晶胞体积增大。

Investigate the effect of rapid quenching on the electrochemical performances and microstructures of the rear-earth-based low-Co AB5-type Lax Mm1-x （NiMnSiA1Fe）4.7 Co0. 2 （x = 0,1） hydrogen storage alloys. The obtained results show that： Rapid quenching improves the cycle stability of the alloys because rapid quenching can make the lattice volume of alloys larger and the grain size smaller,and it is notable to the as-quenched La0 alloys, this was mainly attributed to the smaller grain produced by rapid quenching than Lal alloys. The substitution La for Mm improves the discharge capacity of the alloys because the substitution La for Mm makes the secondary phase disappear and the lattice volume enlarge.