XAS study of the structural and electronic changes in the negative electrode LiNiVO4 during battery discharge
Résumé
2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonate), ABTS, has been studied by X-ray crystallog. and its structure solved from single crystal diffraction data. The title compd. has monoclinic symmetry and belongs to the P21/c space group. Cell parameters are: a=0.8707(1), b=3.6843(7), and c=0.8222(1) nm,α=97.18(3)° with four formula units per cryst. cell. The structure is built of two types of pseudo-planar mols. ABTS crystallizes with two very labile water mols. as demonstrated from the structural detn. and supported by IR and thermogravimetric analyses. From the structural detn. and the calcd. spin d. matrix, it is possible to explain the complex ESR behavior of ABTS and its intercalated derivs. previously obsd. in the solid state. Changes in ESR spectra with temp. mainly arise from water mol. removal, and not from mol. deformations or thermally activated electron transfers.