Layered perovskite-type Nd2Ti2O7 energy-storage ceramics with ultrahigh Eb (∼1.4 MV cm−1) and large Eg (∼3.76 eV)

Abstract

Dielectric ceramic capacitors have garnered extensive attention due to their fast charge–discharge speed, high power density, and thermal stability. This paper investigates Nd₂Ti₂O₇ ceramics, which are characterized by a monoclinic layered perovskite structure exhibiting a relatively uniform charge distribution. This structure can have a quick response to external electric fields. It can lead to an intrinsic energy storage efficiency of 85.6%. Furthermore, the uniform and compact microstructure of the ceramics minimizes internal defects, thereby preventing heat buildup during charging and discharging processes. This characteristic contributes to achieving a high breakdown electric field (∼1.4 MV cm⁻¹). The effective energy-storage density of the Nd₂Ti₂O₇ ceramics was determined to be 6.56 J cm⁻³, and through variations in frequency and temperature during testing, excellent frequency and temperature stability were observed. Meanwhile, the dielectric constant of Nd₂Ti₂O₇ ceramics is approximately 38 at room temperature, and the forbidden bandwidth is estimated to be approximately 3.76 eV through spectroscopic techniques. Further, the average density of the samples was able to reach ∼6.073 g cm⁻³. The perovskite-type Nd₂Ti₂O₇ ceramics present favorable prospects for applications in the development of pulse dielectric capacitors.