Application of X-ray and Neutron Scattering Techniques in Materials Research: Lithium Batteries and Electronic Ceramics

摘要

X-ray and neutron powder diffraction provide complementary information on the structures of inorganic complex oxides, primarily because of the different dependence of atomic scattering power, or scattering length, on atomic number. Neutron diffraction is particularly useful for characterising novel lithium transition metal oxides which have applications in prototype advanced lithium battery systems. Thus, it is possible to establish conduction pathways for mobile Li+ ions and to distinguish between transition metal ions in ordered spinel structures such as Li2NiMn3O8, which has a charge-discharge potential of 4.7V. An additional feature of such materials is oxygen non-stoichiometry in which their oxygen content depends on sample preparation conditions and temperature. This oxygen non-stoichiometry may be analysed by thermogravimetry and the transition metal oxidation states determined, in the solid state, by the X-ray absorption technique, XANES. Structural changes as a function of temperature may be followed by high temperature diffraction methods and as a function of lithium content during charging/discharging of lithium batteries by in situ synchrotron XRD. A range of examples of the applications of these techniques will be presented.