This study systematically analyzed the effects of sintering temperature and compressive stress on the ionic conductivity of β''-alumina pellets. The pellets were prepared at three sintering temperatures: 1500 °C, 1550 °C, and 1600 °C, with some undergoing a separate pre-sintering compression process to induce initial densification. The pellets subjected to the pre-sintering compression process were sintered under 4 MPa pressure, and their ionic conductivity was measured under compressive stresses of 6 N, 8 N, and 10 N after sintering. In contrast, the pellets without the pre-sintering compression process were analyzed under a 10 MPa sintering condition and compressive stresses of 0 N, 1 N, 2 N, and 4 N. At 1550 °C, the pellets exhibited optimal ionic conductivity, reaching a maximum of 3.99766×10⁻⁶ S/cm without the pre-sintering compression process and 2.50621×10⁻⁶ S/cm with it. At 1500 °C, the conductivity was low due to the small grain size, while at 1600 °C, it decreased due to insufficient densification. Compressive stress further enhanced conductivity, with the highest performance observed at stress levels of 4 N and 10 N. These results highlight the importance of optimizing the manufacturing process for β''-alumina and suggest its potential for application in all-solid-state batteries.

Keywords: β''-alumina, Ionic conductivity, Sintering temperature, Compressive stress.