Promoting the cycling stability of amorphous MgNi-based alloy electrodes by mitigating hydrogen-induced crystallization

MgNi-based amorphous alloy is a potential candidate to anode material of Nickel-Metal hydride battery because of its high capacity and low cost. However, the poor cycle life hinders its practical application. In this work, the effect of alloying elements (In, Al, Cu, Sc) on the thermal stability of the amorphous structure of MgNi alloy has been investigated by XRD, DSC, and TG methods. It is found that the addition of In and Al could greatly increase the crystallization temperature of the amorphous phase and impede the formation of crystalline hydride during the dis-/charging cycle. Therefore, the cycling performance of MgNi-based amorphous alloy electrodes is much improved. Therefore, it is indispensable to evaluate the role of alloying elements to the thermal stability of the amorphous structure as optimizing the composition of MgNi-based alloys. This work also suggests that the multi-component composition is beneficial to the structural and cyclic stability of MgNi-based alloys. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The addition of In and Al to MgNi-based amorphous alloy can improve the crystallization temperature of the amorphous phase and hinder the formation of crystalline hydride, leading to enhanced cycling performance. Therefore, optimizing the alloy composition is crucial for improving the performance of MgNi-based alloys, and multi-component composition is beneficial for enhancing their structural and cyclic stability.