BaTiO₃-Based Multilayers with Outstanding Energy Storage Performance for High Temperature Capacitor Applications

Abstract

With the ultrahigh power density and fast charge–discharge capability, a dielectric capacitor is an important way to meet the fast increase in the demand for an energy storage system such as pulsed power systems (PPS). The BaTiO3-based capacitor is considered as one of the candidates for PPS due to its high permittivity. However, with the continuous miniaturization of PPS, the demand further increases in energy density and thermal stability of BaTiO3-based capacitors. Thus, this work describes a new high performance multilayer ceramic capacitor (MLCC) of BaTiO3–xBi(Li0.5Nb0.5)O3 (BT–xBLN) (0.0 ≤ x ≤ 1.0) for PPS. On the basis of the XRD and dielectric constant of BT–xBLN (0.0 ≤ x ≤ 1.0) ceramics, all compositions exhibited an average perovskite structure (tetragonal phase, 0.0 ≤ x < 0.05; pseudocubic phase, 0.05 ≤ x < 0.4) and multiple phase (0.4 ≤ x < 1.0). For example, the 0.90BaTiO3–0.10Bi(Li0.5Nb0.5)O3 multilayer ceramics capacitors were characterized by charge efficiency (η ≥ 91.5%), discharge energy density (Ue ∼ 4.5 J cm–3), breakdown strength (Eb > 450 kV cm–1), and good thermal stability, demonstrating their potential in PPS. This work makes breakthroughs in BaTiO3-based capacitor materials with high Ue and adds a new member to the BaTiO3-based dielectric capacitor material family for the energy storage field.