Electrochemical hydrogen storage properties of mechanically alloyed Mg0.8Ti0.2-xMnxNi (x 1/4 0, 0.025, 0.05, 0.1) type alloys

Mechanical alloying was used in the synthesis of Mg0.8Ti0.2-xMnxNi (x = 0, 0.025, 0.05, 0.1) quaternary alloys to analyze the effect of Mn substitution for Ti on the electrochemical performance of MgNi alloys. The milling was carried out for 25 h. By adding a small amount of Mn (x = 0.025) to the Mg0.8Ti0.2Ni alloy, a completely amorphous structure was obtained. The maximum discharge capacity of the Mg0.8Ti0.175Mn0.025Ni alloy was observed as 543 mAh g-1at the initial charge/discharge cycle. When x = 0 and x = 0.05, the discharging performances of Mg0.8Ti0.2-xMnxNi alloys were approximately the same. However, when x = 0.1, the lowest initial discharge capacity (401 mAh g-1) and discharge capacity performance were observed. The capacity retention rates of Mg0.8Ti0.175Mn0.025Ni, Mg0.8Ti0.2Ni, Mg0.8Ti0.05Mn0.05Ni, and Mg0.8Ti0.1Mn0.1Ni alloys were 81%, 68%, %67, and 47%, respectively, at the 20th cycle. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Mechanical alloying was used to synthesize Mg0.8Ti0.2-xMnxNi quaternary alloys, with the addition of a small amount of Mn resulting in an amorphous structure and affecting the electrochemical performance. The Mg0.8Ti0.175Mn0.025Ni alloy showed the highest discharge capacity at the initial charge/discharge cycle.