Computational and experimental investigations into the Li+, Mg2+, and Mg2+/Li+ dual-cation transport properties within the Chevrel phase Mo6S8 have been performed. Five representative paths were selected for 3D diffusion, and their corresponding energy barriers were determined. Based on density functional theory calculation results, we reveal phenomena of the cation trapping, sluggishness of Mg2+ ion transport, and synchronized movement of inserted cations induced by repulsive interactions. The computational results were further validated by cyclic voltammetry carried out at ambient to high temperatures, from which apparent diffusion constants and activation energies for each case were determined. We found broad agreement between the theoretical and experimental results and suggest an optimum scenario for charge-discharge processes within the dual-cation hybrid system. (Chemical Equation Presented).
Bibliographical noteFunding Information:
This work was supported by the Energy Efficiency & Resources Program of the Korea Institute of Energy Technology Evaluation and Planning (Project No. 20142020103090) grant funded by the Korean government Ministry of Trade, Industry & Energy and the KIST institutional program (Project No. 2E26292). We also acknowledge the support of Materials Design (www.materialsdesign.com/medea) and Kyungwon Enc. (www.kwenc.kr) for granting us the use of the MedeAVASP program.
© 2017 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films