1999 Volume 67 Issue 1 Pages 68-71
LiCo0.5Ni0.5O2, LiAl0.25Ni0.75O2 and Li4Mn5O12 films were prepared by electrostatic spray deposition (ESD) onto gold substrates, and thelr stabilities in (62+38) mol% (Li+K) CO3 at 923K under an oxidant gas condition were investigated by XRD and EDX techniques. XRD measurements revealed that after immersion in the melt, the LiCo0.5Ni0.5O2 maintained the hexagonal structure, while the cubic phase of Li4Mn5O12 changed to a monoclinic of Li2MnO3. The XRD pattern of LiAl0.25Ni0.75O2 showed low crystallinity. The atomic ratios of Co/Ni and Al/Ni in the Ni-containing oxide films were found to be increased after immersion in the melt by EDX analysis, indicating that the nickel partly dissolved into the melt. The oxygen reduction currents at all the films were observed by cyclic voltammetry. It showed that the use of manganese is also hopeful as a cathode material of MCFC.