制备工艺对AB_5型高容量贮氢合金电化学性能的影响

Effect of Preparation Process on Electrochemical Performances of AB 5 -Type High Capacity Hydrogen Storage Alloys

研究了快淬、热处理、快淬+热处理制备工艺对铸态(LaCe)1.0(NiCoMnAl)5.0高容量贮氢合金电化学性能的影响。XRD分析表明所有合金均为单相CaCu5型结构,快淬+热处理合金相的成分和结构的均匀性最好。电化学测试结果表明,与铸态合金相比,热处理合金的放电容量和循环性能有所提高,但其倍率性能明显降低;快淬合金的活化性能、放电容量、倍率性能以及循环性能均降低;快淬+热处理合金综合电化学性能最好,具有较好的活化性能、最大的放电容量(344.7mA/g)、最大容量保持率(S100,85.67%)以及较好的倍率性能。

The effects of rapid quenching, heat treatment and rapid quenching followed by heat treatment （rapid quenching＋heat treatment） on the electrochemical performances of （LaCe）l.0（NiCoMnA1）5,0 hydrogen storage alloy were investigated. XRD analyses indicate that all the alloys are of single phase CaCus-type structure, and the alloy of rapid quenching＋heat treatment has the best crystallizability and homogeneity. The results of electrochemical measurement show that compared with the as-cast alloy, the discharge capacity and cycle stability of the heat treated alloy are improved, but the high-rate discharge capability is significantly reduced. The activation performance, discharge capacity, high-rate discharge capability and cycle stability of the quenched alloy are reduced. Rapid quenching＋heat treatment obviously improves comprehensive electrochemical performances of the cast alloy, so the alloy of rapid quenching＋heat treatment has good activation capability, better discharge capacity （344.7 mA/g）, higher capacity retaining rate （S100, 85.67%） and better high-rate discharge capability.