抄録
To develop the high-volume energy storage device based on ceramic capacitors, we attempted that Ti metal particles working as internal electrodes were distributed in barium titanate (BT) layers. We compared two kinds of the metal particles; uncoated Ti metal particles and Ti-BT core-shell particles (Ti metal particles with thin BT coating layers). The green compacts consisting of the metal particles, titanium oxide precursor particles, and barium titanate fillers were successfully converted into the Ti/BT composite compacts by the hydrothermal method without heating procedure. The effective dielectric constant of these composites tends to increase with a metal content, and then drastically increases up to over 103 near the percolation threshold (insulator-metal transition point). These dielectric constant behaviors can be explained by the percolation theory. By using the core-shell particles, the percolation threshold increases from 0.609 to 0.734, suggesting that the BT shell layers were effective to suppress the current leakage.
