TiSnSb a new efficient negative electrode for Li-ion batteries: mechanism investigations by operando-XRD and Mossbauer techniques

Moulay Tahar Sougrati (1, 2) , Fullenwarth Julien (3) , Aurore Debenedetti (3) , Bernard Fraisse (1) , Jean-Claude Jumas (1) , Laure Monconduit (1, 3)

1 ICGM ICMMM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 LAMMI - Laboratoire des Agrégats Moléculaires et Matériaux Inorganiques

We report the electrochemical study of TiSnSb towards Li, as a negative electrode for Li-ion batteries. TiSnSb can reversibly take up more than 5 lithiums per formula unit leading to reversible capacities of 540 mA h g−1 and 4070 mA h cm−3 at 2 C rate. From complementary operando XRD and Mössbauer spectroscopy measurements, it was shown that during the first discharge the TiSnSb undergoes a conversion process leading simultaneously to the formation of Li-Sb and Li-Sn alloys. At the end of the discharge, Li3Sb and Li7Sn2 were identified. Once the first discharge is achieved, both phases were shown to form Ti-Sn or Ti-Sb or Ti-Sn-Sb nanocomposites. The cycling performance of TiSnSb was shown to be excellent with maintaining 90% of the specific capacity during 60 cycles at 2 C rate. The good electrochemical performance of TiSnSb (compared to Sn and Sb) seems to be a consequence of the presence of the non-active metal. The comparative study of Ti/Sn/Sb composite demonstrated that the structural feature of the pristine material clearly impacts both the mechanism involved during the cycling and the corresponding performance.

Mots clés: TiSnSb; Li-ion; conversion; In situ; operando; Mössbauer

Domaines: Matériaux

Moulay Tahar Sougrati, Fullenwarth Julien, Aurore Debenedetti, Bernard Fraisse, Jean-Claude Jumas, et al.. TiSnSb a new efficient negative electrode for Li-ion batteries: mechanism investigations by operando-XRD and Mossbauer techniques. Journal of Materials Chemistry, 2011, 21, pp.10069-10076. ⟨10.1039/C1JM10710K⟩. ⟨hal-00606312⟩