Enhanced Energy Storage Performance of MnO₂-Modified 0.92BaTiO₃–0.08Bi(Mg_0.5Ce_0.5)O₃ Ceramics for Capacitor Applications

Abstract

Composition of ceramics 0.92BaTiO3–0.08Bi­(Mg0.5Ce0.5)­O3 + xwt % MnO2 {designated as BTBMC-x wt % Mn} (0.00 ≤ x ≤ 0.20) was fabricated via a solid-state sintering route for the investigation of phase, microstructure, dielectric, electrical, and energy storage behaviors. X-ray diffraction results indicated a single phase without an impurity phase. The MnO2 additive led to a decrease in the average grain size of BTBMC to ≤0.2 μm (submicron), which decreased the electrical conductivity from ∼10–6 s cm–1 to ∼10–10 s cm–1 when the x value increased from 0.00 to 0.20. This small conductivity is responsible for the enhancement of the dielectric breakdown strength (BDS) up to 315 kV cm–1 with an energy storage density (W s) of ∼2.688 J cm–3 and a recoverable energy density (W rec) of ∼1.684 J cm–3 for x = 0.20. This ceramic system is chosen to be a good candidate for advanced capacitor applications.

Structural, dielectric, electrical, and energy storage properties of Mn‐doped Ba0.55Sr0.45TiO3 ceramics

“…The magnitude of ɛ r was observed to decrease with the increase in temperature and frequency. 15,16 The ɛ r(max) value decreased from 6150 to 1200 for the x = .004-.015 samples at 1 kHz, as shown in Figure 3E. T m is the temperature at which ɛ r observed maximum was observed to shift to the high temperature side with a successive increase in x values except .015, as shown in Table 1.…”

“…which suppress the movement of oxygen vacancies. 16 Figure 5F expresses the σ versus T plots at 1 kHz, exhibiting a very small variation in σ with a rise in temperature (500-575 • C) showing thermal stability. The activation energy (E a ) can be calculated using the Arrhenius Equation ( 7).…”

“…14 Rajan et al investigated the best dielectric response in Fe-Mn-doped BaTiO 3 ceramics. 15 Rehman et al 16 investigated the improved energy storage behaviors of MnO 2 -modified BaTiO 3 -based ceramics via an additive strategy. It has been reported that small amount of Mn doping decreased the grain size and hence improved the energy storage performance of ceramics prominently.…”