Chemical and electrochemical insertion of Li into the spinel structure of CuCr2Se4: ex situ and in situ observations by X-ray diffraction and scanning electron microscopy.

The chemical and electrochemical insertion of lithium into the spinel structure of CuCr(2)Se(4) was studied and the chemical reaction pathway was followed by ex situ X-ray diffraction on samples with different Li contents. The electrochemical reaction was investigated by in situ X-ray diffraction and in situ scanning electron microscopy. In the early steps of chemical intercalation, two phases with a different Li content coexist and Cu is extruded from the host material.

Study of local structure and Li dynamics in Li(4+x)Ti(5)O(12) (0 ≤ x ≤ 5) using (6)Li and (7)Li NMR spectroscopy.

We studied the local structure and the Li ion dynamics in electrochemically and chemically prepared Li(4+x)Ti(5)O(12) with x = 0…5. We used magic-angle spinning (7)Li NMR on samples with different Li contents to investigate the sites that are occupied/emptied during Li insertion/removal. While the electrochemical measurements show a lithium insertion in two steps, 1D MAS NMR as a function of the lithium content shows that the overall spectral evolution observed during lithium insertion is inverted during lithium removal.