The Electrochemical Sodiation of Sb Investigated by Operando X-ray Absorption and 121Sb Mössbauer Spectroscopy: What Does One Really Learn?

Batteries

Marcus Fehse¹  Lorenzo Stievano¹  Abdelfattah Mahmoud²  Mouna Ben Yahia³  Bernard Fraisse³  Laure Monconduit³  MoulayT. Sougrati³  Marie-Liesse Doublet³  Ali Darwiche³  RaphaelP. Hermann⁴  Camille La Fontaine⁵ 

[1] Dutch-Belgian (DUBBLE), ESRF-The European Synchrotron, 38043 Grenoble, France;GreenMat, CESAM, Institute of Chemistry B6, University of Liège, 4000 Liège, Belgium;ICGM, Université de Montpellier, CNRS, 34095 Montpellier, France;Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37813, USA;Synchrotron Soleil, Saint-Aubin, 91192 Gif-sur-Yvette, France;

关键词: X-ray absorption spectroscopy;    Mössbauer spectroscopy;    DFT calculations;    chemometrics;    MCR-ALS;    Na-ion batteries;    alloy reaction;    Sb;   

DOI  :  10.3390/batteries4020025

来源: DOAJ

【 摘 要 】

In this study, we want to highlight the assets and restrictions of X-ray absorption spectroscopy (XAS) and Mössbauer spectroscopy for investigating the mechanism of the electrochemical reaction of antimony electrode materials vs. Na. For this, operando XAS was carried out during the first one and a half cycles, and the whole set of measured data was analysed using a statistical-chemometric approach, while low temperature Mössbauer spectroscopy measurements were carried out ex situ on selected samples stopped at different points of the electrochemical reaction. Complementary ab initio calculations were performed to support the experimental findings. Both techniques show that, upon the first sodiation, most Sb reacts with Na to form disordered Na 3Sb. This step is accompanied by the formation of amorphous Sb as an intermediate. Upon inversion of the current Na 3Sb is desodiated and an amorphous Sb phase, distinct from the pristine bulk Sb state, is gradually formed. However, both XAS and Mössbauer spectroscopy were unable to spot the formation of intermediate Na xSb phases, which were evinced in previous works by operando Pair Distribution Function analyses. The results shown here clearly assign such failure to the intrinsic inability of both techniques to identify these intermediates.

【 授权许可】

Unknown