Durable MCFC electrolyte plate consisting of alpha- and beta-LiAlO2

The stability of rod-shaped beta-phase lithium aluminate was tested to evaluate its suitability for use as a reinforcing material for alpha-phase lithium aluminate electrolyte plates. In contrast to previous reports, the beta-phase which was added to the alpha-phase remained stable at 750 degrees C. Our study confirmed that there was a difference in allotropic transformation between beta-phase with alpha-phase and beta-phase with gamma-phase. The electrolyte plate consisting of beta-phase with alpha-phase showed an obvious improvement of the rate of pore coarsening at 650 degrees C in an atmosphere containing steam. This suggests that a combination of alpha-phase and beta-phase will be an effective substitute for currently used MCFC electrolyte plate materials.