Compounds with spinal related structure are interesting as insertion electrodes because of the large number of vacant sites available to insertion and the possibilities for varying the oxidation state and nature of elements, the degree of vacant sites and the distribution of the into the structure.
For this study the spinel host systems has been selected . The nominal composition of the compounds to be studied is: (Cu)[M0.5Snl.5]S4 with M = Mn, Fe, Co and Ni. The aims are:
- the analysis of the inserted Li and electrons in the lattice.
- the modelization of insertion in such materials.
This will be performed by simultaneous X-ray powder diffraction, high resolution NMR, X-ray absorption, Mossbauer measurements and tight binding calculations.
The novelty of this approach is also the attempt to relate physical concepts as may arise in a fundamentally-based model with chemical notions of ionicity and covalence which are of use in finding better routes to synthesis.