TY - JOUR
T1 - In-Depth Analysis of the Conversion Mechanism of TiSnSb vs Li by Operando Triple-Edge X-ray Absorption Spectroscopy
T2 - A Chemometric Approach
AU - Fehse, Marcus
AU - Darwiche, Ali
AU - Sougrati, Moulay T.
AU - Kelder, Erik M.
AU - Chadwick, Alan V.
AU - Alfredsson, Maria
AU - Monconduit, Laure
AU - Stievano, Lorenzo
PY - 2017/12/26
Y1 - 2017/12/26
N2 - The electrochemical cycling mechanism of the ternary intermetallic TiSnSb, a promising conversion-type negative electrode material for lithium batteries, was thoroughly studied by operando X-ray absorption spectroscopy (XAS) at three different absorption edges, i.e., Ti, Sn, and Sb K-edge. Chemometric tools such as principal component analysis and multivariate curve resolution-alternating least squares were applied on the extensive data set to extract the maximum contained information in the whole set of operando data. The evolution of the near-edge (XANES) fingerprint and of the extended fine-structure (EXAFS) of the XAS spectra confirms the reversibility of the conversion mechanism, revealing that Ti forms metallic nanoparticles upon lithiation and binds back to both Sn and Sb upon the following delithiation. The formation of both Li7Sn2 and Li3Sb upon lithiation was also clearly confirmed. The application of chemometric tools allowed the identification of a time shift between the reaction processes of Sn and Sb lithiation, indicating that the two metals do not react at the same time, in spite of a certain overlap between their respective reaction. Furthermore, XANES and EXAFS fingerprint show that the Ti-Sn-Sb species formed after one complete lithiation/delithiation cycle is distinct from the starting material TiSnSb.
AB - The electrochemical cycling mechanism of the ternary intermetallic TiSnSb, a promising conversion-type negative electrode material for lithium batteries, was thoroughly studied by operando X-ray absorption spectroscopy (XAS) at three different absorption edges, i.e., Ti, Sn, and Sb K-edge. Chemometric tools such as principal component analysis and multivariate curve resolution-alternating least squares were applied on the extensive data set to extract the maximum contained information in the whole set of operando data. The evolution of the near-edge (XANES) fingerprint and of the extended fine-structure (EXAFS) of the XAS spectra confirms the reversibility of the conversion mechanism, revealing that Ti forms metallic nanoparticles upon lithiation and binds back to both Sn and Sb upon the following delithiation. The formation of both Li7Sn2 and Li3Sb upon lithiation was also clearly confirmed. The application of chemometric tools allowed the identification of a time shift between the reaction processes of Sn and Sb lithiation, indicating that the two metals do not react at the same time, in spite of a certain overlap between their respective reaction. Furthermore, XANES and EXAFS fingerprint show that the Ti-Sn-Sb species formed after one complete lithiation/delithiation cycle is distinct from the starting material TiSnSb.
UR - http://resolver.tudelft.nl/uuid:0ba04e58-35f5-48fe-ae60-23390ce359ce
UR - http://www.scopus.com/inward/record.url?scp=85040084832&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.7b04088
DO - 10.1021/acs.chemmater.7b04088
M3 - Article
AN - SCOPUS:85040084832
SN - 0897-4756
VL - 29
SP - 10446
EP - 10454
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 24
ER -