Sputtered amorphous thin film nanocomposites as an anode for lithium-ion batteries

Abstract In order to overcome the pulverization problem of Ge-based anode materials with high capacity, we use the co-sputtering deposition method to prepare thin film nanocomposites (Ge–TiN), containing amorphous Ge and TiN, as an anode for use in high-performance LIBs. Compilation of the data from XRD, Raman, and TEM suggests that the nanocomposites consist of amorphous Ge and TiN phases in the presence of phase separation. From the XPS and EDX data, the nanocomposites show homogeneous distribution of Ge and TiN both on the surface and in the bulk of the electrodes. In the active–inactive composite, Ge acts as a reactant during the lithiation process, forming Li x Ge, which is surrounded by an inactive TiN matrix. The Ge–TiN nanocomposites demonstrate relatively high reversible capacities, and show good capacity retention ratios and excellent high rate cycling performance even at a high current rate.