American Chemical Society
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Potential Application of MgCu2 Alloy as a High-Performance Electrode Material for Mg-Ion Batteries: A Computational Study

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journal contribution
posted on 2023-12-05, 21:14 authored by Rong Li, Junhan Wu, Zhongting Wang, Yumei Wang, Jingdong Yang, Rongrui Deng, Guangsheng Huang, Xiaoyuan Zhou, Jingfeng Wang, Fusheng Pan
Alloyed electrode materials are considered as potential high-performance anodes for Mg-ion batteries (MIBs). Herein, employing first-principles calculations, we reveal the feasibility of MgCu2 alloys as anode materials for MIBs. This work shows that the inherent metallicity, excellent electrical conductivity, and thermal, dynamic, and mechanical stability of MgCu2 can contribute to the high-rate performance and stability in batteries. It is found that the volume expansion rate from MgCu2 to Mg2Cu is only 107.37%, which avoids the failure caused by the large volume change. Besides, MgCu2 possesses small Young’s moduli, regulating the volume change during charging/discharging. Especially, MgCu2 not only has a low open-circuit voltage (0.221 V) but also a theoretical capacity as high as 1688 mA h/g when forming Mg2Cu. In addition, both MgCu2 and the final product Mg2Cu have low diffusion energy barriers of Mg ions (0.318 and 0.307 eV), which implies the high cycle rate potential. The transformation mechanism investigation during the formation of Mg2Cu from MgCu2 indicates that Mg ions are first adsorbed on the (1 0 0) surface of MgCu2 before conversion and then directly convert to the final Mg2Cu. In conclusion, MgCu2 shows strong suitability as an ideal anode material for MIBs.