High Energy Density Achieved in Novel Lead-Free BiFeO₃–CaTiO₃ Ferroelectric Ceramics for High-Temperature Energy Storage Applications

Abstract

The development of high-performance electrostatic energy storage dielectrics is essential for various applications such as pulsed-power technologies, electric vehicles (EVs), electronic devices, and the high-temperature aviation sector. However, the usage of lead as a crucial component in conventional high-performance dielectric materials has raised severe environmental concerns. As a result of this, there is an urgent need to explore lead-free alternatives. Ferroelectric ceramics offer high energy density but lack stability at high temperatures. Here we present a lead-free (1 − x)BiFeO 3 −xCaTiO 3 (x = 0.6, 0.7, and 0.8; BFO-CTO) ceramic capacitor with low dielectric loss, high thermal stability, and high energy density up to ∼200 °C. The introduction of CTO (x = 0.7) to the BFO matrix triggers a transition from the normal ferroelectrics to the relaxor ferroelectrics state, resulting in a high recoverable energy density of 1.18 J cm −3 at 190 °C with an ultrafast dielectric relaxation time of 44 μs. These results offer a promising, environmentally friendly, high-capacity ceramic capacitor material for high-frequency and high-temperature applications.

Study of Dielectric Relaxation Dynamics and Transport Properties of Nd3+-Substituted Bismuth Ferrite Ceramics for Energy Storage Applications

“…) ,− or BFO-ABO 3 (BTO, CTO, and STO etc.) composites. − In the current study, XPS analysis was employed to determine the valence state of Fe-ions, and the deconvoluted data are shown in Figure (b) (the original XPS data are shown in Figure S2). The photoemission peaks at 709.9 and 711.1 eV correspond to the Fe 2+ and Fe 3+ states of Fe 2 p 3/2 .…”

“…The efficiency exhibited a substantial increase up to 2 kV, beyond which there was only a marginal improvement in efficiency (η) as the applied voltage was raised to 2.5 kV (shown in Figure (c)). The obtained total energy stored, recoverable energy and the efficiency is quite significant compared to similar bulk systems reported in the literature …”