Decarbonization of the Ce₂Mn₁₇C_1.77 compound upon lithiation

Chem. Met. Alloys 10 (2017) 45-49

https://doi.org/10.30970/cma10.0352

Mykola HEMBARA, Vasyl KORDAN, Volodymyr PAVLYUK, Bogdan KOTUR

The ternary compound Ce₂Mn₁₇C_1.77 was investigated by means of X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray analysis. The structure type Pr₂Mn₁₇C_1.77 was confirmed using the Rietveld method. Electrochemical lithiation of Ce₂Mn₁₇C_1.77 was carried out in Swagelok-type cells with a positive electrode containing LiCoO₂ over 30 cycles. Decarbonization of the Ce₂Mn₁₇C_1.77 ternary carbide upon lithiation was accompanied by a decrease of the cell volume (from 847.9(2) Å³ to 842.7(5) Å³) and formation of α-Li₂C₂, Li_xC_y carbides, and amorphization of the Ce₂Mn₁₇ subcell. The morphology of the anode surface underwent changes and the grain size of the material decreased.

Crystal structure of Ce₂Mn₁₇C_1.77.

Keywords

Carbides / Crystal structure / Isostructural compounds / Electrochemical lithiation