Electrochemical reactivity of In-Pb solid solution as a negative electrode for rechargeable Mg-ion batteries

A composite In-Pb:carbon was successfully synthetized by a two-step mechanochemical synthesis in order to obtain an adequate particles size and structure to investigate the electrochemical reactivity of the In-Pb solid solution towards Mg. A potential synergetic coupling of electroactive elements In and Pb was examined using electrochemical and ex situ X-ray diffraction analyses. The potential profile of the solid solution indicates the formation of Mg2Pb and MgIn. However, the diffraction study suggests a peculiar electrochemically-driven amorphization of MgIn during the magnesiation, in strong contrast to MgIn crystallization in In-based and InBi-based electrodes reported in the literature. Combining In and Pb favors the amorphization of MgIn and a high first magnesiation capacity of about 550 mAh g(-1), but is thereafter detrimental to the material's reversibility. These results emphasize the possible influence of electrochemically-driven amorphization and crystallization processes on electrochemical performance of battery materials. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.