Electrochemical lithiation of Ti₅M₃, Ti₃M and Zr₃M (M = Sn, Sb) binary intermetallics

Chem. Met. Alloys 9 (2016) 84-91

https://doi.org/10.30970/cma9.0327

Vasyl KORDAN, Oksana ZELINSKA, Volodymyr PAVLYUK, Igor OSHCHAPOVSKY, Roman SERKIZ

The binary phases Ti₅M₃, Ti₃M and Zr₃M (M = Sn, Sb) were studied for electrochemical lithiation, using powder X-ray diffraction, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The investigation showed that the morphology of the cathode and the anode surfaces undergo changes, and the grain size of the materials decreases. The phase analysis of the anode materials revealed that the Ti₅Sn₃ (structure type Mn₅Si₃) and Ti₃Sn (structure type Mg₃Cd) phases form solid solutions by insertion of Li atoms into the initial structure. The insertion is reversible. The phases Ti₅Sb₃ (structure type Y₅Bi₃), Ti₃Sb, Zr₃Sn (structure type Cr₃Si), and Zr₃Sb (structure type Ni₃P) form solid solutions by substitution of Li for Sn or Sb atoms. Only the Zr₃Sb phase showed weakly reversible substitution. Among the investigated compounds, the most suitable structure types for intercalation of lithium appeared to be the Mn₅Si₃- and Mg₃Cd-types, where the Li atoms occupy octahedral voids. The intermetallic compounds containing tin showed better ability for electrochemical lithiation than the compounds containing antimony. This can be explained by the easier interaction of antimony and lithium with the formation of binary compounds.

Projection of the unit cells of Ti₅Sn₃Li_x (a) and Ti₃SnLi_x (b).

Keywords

Intermetallic compound / Electrochemical lithiation / Li-ion battery