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Yu P, Long X, Zhang N, Feng X, Fu J, Zheng S, Ren G, Liu Z, Wang C, Liu X. Charge Distribution on S and Intercluster Bond Evolution in Mo 6S 8 during the Electrochemical Insertion of Small Cations Studied by X-ray Absorption Spectroscopy. J Phys Chem Lett 2019; 10:1159-1166. [PMID: 30789737 DOI: 10.1021/acs.jpclett.8b03622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Mo6S8 is regarded as a promising cathode material in rechargeable Mg batteries. Despite extensive studies, some fundamental questions are still unclarified, including the origination of the chemical stability, key factors inducing the structural evolution, and the factors determining the electrochemical reversibility. Herein Mo L2,3 and S K-edge X-ray absorption spectroscopy are utilized to uncover the underlying mechanism. Two kinds of S with different effective charge are found, indicating the nonuniform charge distribution. With one cation inserted, the charge distribution becomes homogeneous, relevant to the chemical stability and electrochemical reversibility. The structural evolution is attributed to the change of bond length induced by the delocalization of inserted cations. Moreover, the evolution of intercluster Mo-Mo bond length can be revealed by the drastic change of the S K pre-edge and is closely related to the electrochemical reversibility. This study can shed light on the aforementioned questions and guide the development of Mg cathode material.
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Affiliation(s)
- Pengfei Yu
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
- Tianmu Lake Institute of Advanced Energy Storage Technologies , Liyang City , Jiangsu 213300 , China
| | - Xinghui Long
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
| | - Nian Zhang
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
| | - Xuefei Feng
- Advanced Light Source , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Jiamin Fu
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
- School of Physical Science and Technology , Shanghai Tech University , Shanghai 200031 , China
| | - Shun Zheng
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
| | - Guoxi Ren
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
| | - Zhi Liu
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
- School of Physical Science and Technology , Shanghai Tech University , Shanghai 200031 , China
| | - Cheng Wang
- Advanced Light Source , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Xiaosong Liu
- State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai 200050 , China
- Tianmu Lake Institute of Advanced Energy Storage Technologies , Liyang City , Jiangsu 213300 , China
- School of Physical Science and Technology , Shanghai Tech University , Shanghai 200031 , China
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