Investigation on the effect of Co doping on structure, electronic, and hydrogen storage properties of Mg2FeH6

Li Ping Ding; Fei Yue Qiao; Hong Yuan Xu; Shao Fei Lei; Peng Shao

doi:10.1016/j.jmgm.2024.108916

Investigation on the effect of Co doping on structure, electronic, and hydrogen storage properties of Mg₂FeH₆

J Mol Graph Model. 2024 Nov 27:135:108916. doi: 10.1016/j.jmgm.2024.108916. Online ahead of print.

Authors

Li Ping Ding¹, Fei Yue Qiao², Hong Yuan Xu², Shao Fei Lei², Peng Shao²

Affiliations

¹ Department of Optoelectronic Science & Technology, School of Electronic Information and Artificial Intelligence, Shaanxi University of Science & Technology, Xi'an, Shaanxi, 710021, China; Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China; National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China. Electronic address: scu_ding@163.com.
² Department of Optoelectronic Science & Technology, School of Electronic Information and Artificial Intelligence, Shaanxi University of Science & Technology, Xi'an, Shaanxi, 710021, China.

PMID: 39626580
DOI: 10.1016/j.jmgm.2024.108916

Abstract

Metal hydrides, particularly magnesium-based materials, exhibit excellent hydrogen storage capabilities. Among these, Mg₂FeH₆ stands out for its high hydrogen storage capacity, but it faces limitations due to low thermodynamic stability and high hydrogen desorption temperature. To overcome these challenges, we investigated the potential of Co doping to improve hydrogen storage properties. Based on first-principles calculations, we systematically explored the structures, electronic properties and hydrogen storage capabilities of a novel Mg-Fe-Co-H alloy. We found that Co doping significantly reduced the band gap by 1.14 eV, promoting electron transitions and accelerating hydrogen desorption kinetics. Additionally, Co doping alters the Fe-H interaction, increasing bond lengths and facilitating the hydrogen dissociation. Although Co doping slightly decreases hydrogen storage capability of Mg₂FeH₆ (from 5.45 wt% to 5.32 wt%), it significantly lowers desorption temperature from 651 K (Mg₂FeH₆) to 543 K (Mg₂Fe_1/8Co_7/8H₆). This study highlights the innovative potential of Co doping to enhance the performance of Mg₂FeH₆-based hydrogen storage materials, offering promising prospects for advancing hydrogen energy technologies.

Keywords: Co doping; Hydrogen storage; Mg(2)FeH(6).