Annealing treatment of AB2-type hydrogen storage alloys: II. Electrochemical properties

Abstract

Abstract As the second part of a study on the effects of annealing treatment on AB 2 -type hydrogen storage alloys, the effect of annealing treatment on electrochemical properties of two multi-component alloys is reported in this paper. The effects on the electrochemical properties are closely related to the stable Laves phase structure. When the stable phase is C15, annealing treatment leads to an increase of the stability of the alloy hydride, a great decrease of the electrocatalytic activity and a significant decrease of the discharge capacity. When the stable phase is C14 after annealing treatment, the stability of its hydride decreases, the electrocatalytic activity decreases slightly, and the discharge capacity remains almost unchanged. For all AB 2 alloys, annealing treatment also leads to deterioration in the activation property and improvement in the cycle life.