Characterization of Mg0.5Al0.25Cr0.25Ni0.25A0.25 (A=Nb,Ta,Co) Alloys as Anode Materials for NiMH Batteries

Hydrogen energy is becoming an important part of a viable solution to worldwide climate change and atmospheric pollution. In this regard, hydrogen storage materials direct the research of rechargeable batteries.High entropy alloys containing Mg consist of an attractive system because Mg is light, cheap, and abundant, and has a high absorption capacity. Mg-containing alloys are an attractive candidate for solid-state hydrogen storage and can be further applied in electrochemical systems where the hydrogen atoms occupy the interstitial forming metal hydride (MH). A Ni/MH battery is composed of a Ni(OH) 2 positive electrode, a metal MH negative electrode and an alkaline electrolyte (KOH solution). The family of hydrogen storage alloys based on transition metals (TM) – Mg – Ni has attracted increasing attention in recent years. They can meet the general electrochemical performance requirements by exhibiting high discharge capacity, long durability, good rate capacity, admirable discharge capacity at low temperature and low self-discharge characteristics. In this direction, it is aimed to add these properties to Mg-based alloys by adding transition metals to Mg-based alloys. In this direction, it is aimed to produce Mg0.5Al0.25Cr0.25Ni0.25A0.25 (A=Nb,Ta,Co) alloys.This alloy electrode will be prepared by melting in a vacuum arc melting furnace under argon atmosphere and with the help of SPEX Ball Mill the alloy will be reduced below 45 microns and then The crystallographic properties of the Mg0.5Al0.25Cr0.25Ni0.25A0.25 (A=Nb,Ta,Co) alloy will be examined. The electrochemical results are aimed at performing charge/discharge tests on NiMH batteries using potentiostat/galvanostat and collecting electrochemical impedance spectrum (EIS) data on the cell.<br/>This work was supported by TUBITAK (The Scientific and Technological Research Council of Turkey) with project Number 121N774, which the authors gratefully acknowledge.