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

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 (Ws) of ∼2.688 J cm–3 and a recoverable energy density (Wrec) of ∼1.684 J cm–3 for x = 0.20. This ceramic system is chosen to be a good candidate for advanced capacitor applications.