Effect of rapid solidification treatment on structure and electrochemical performance of low-Co AB5-type hydrogen storage alloy

姚青荣^1,2,3，唐莹²，周怀营^2,3，邓健秋^2,3，王仲民^2,3，潘顺康^2,3，饶光辉^2,3，朱其明⁴

1. School of Materials and Engineering, Central South University2. School of Materials Science and Engineering,Guilin University of Electronic Technology3. Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology4. School of Science,Guangxi University for Ationalities

摘 要：The effect of rapid solidification on structure and electrochemical performance of the LaNi4.5Co0.25Al0.25 hydrogen storage alloy was investigated by X-ray powder diffraction and a simulated battery test, including maximum capacity, cycling stability, self-discharge, and high-rate discharge ability（HRD）. All the melt-spun alloys were single-phase with the CaCu5-type structure（space group P6/mmm）. In comparison to the as-cast alloy, the rapidly quenched alloys manifested an improved homogeneity of composition and expanded lattice parameters. The electrochemical measurements showed that the activation property, cycling stability and self-discharge of the alloy electrodes were also improved for the rapid solidified alloys. The HRD of the as-cast alloy was better than those of all the rapidly solidified alloys. As the quenching rate increased, the HRD and exchange current density first decreased and then increased.

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