Lithium Alanates as Negative Electrodes in Lithium-Ion Batteries

Hydride conversion reactions have been recently proposed and verified experimentally on simple binary and ternary H-containing materials. Herein, we show for the first time the incorporation of lithium alanates, that is, LiAlH4 and Li3AlH6, as active materials in negative electrodes in rechargeable lithium cells. Samples were prepared by mechanochemical treatment. Characterization of the samples was performed by X-ray diffraction, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Analysis of the electrochemical features of the conversion process was performed by potentiodynamic cycling with galvanostatic acceleration in close comparison with computational data obtained by density functional theory with the use of pseudopotentials and planewaves. The occurrence of the conversion reactions was proved by ex situ synchrotron radiation diffraction experiments. As a final point, the stability of the electrolyte/electrode interface over time was evaluated by impendence spectroscopy and attenuated total reflectance Fourier-transform infrared spectroscopy.