APPLICATION OF NEUTRON RADIOGRAPHY TO VISUALIZE THE MOTION OF LITHIUMIONS IN LITHIUM-ION CONDUCTING MATERIALS

Neutron radiography (NR) has been applied to a lithium in conducting s pinel-type oxide Li1.33Ti1.57O4 in order to visualize the movement of lithium ions. After dc current was passed for electrolysis through spe cially prepared oxides with different isotope ratios (Li-6/Li-7), a se t of NR images was obtained that illustrate the lithium ion conduction in the oxide. Analysts of the NR images determined that the transport number of lithium ions in the spinel-type Li1.33Ti1.67O4 is 0.99 at 9 00 degrees C, which is almost the same as that measured by the oxygen concentration cell method. Further detailed analysis was carried out t o investigate which kind of lithium ion in the oxide ion array of the spinel-type structure contributes to the electric conduction, the tetr ahedral A site lithium, the octahedral B site, or both of these. As a result, the contribution of A site lithium to ionic conduction was con firmed.