High energy storage performance of BaTiO3-based films via breakdown strength and polarization properties synergistic optimization

Dielectric film capacitors, with remarkable high-power densities, charge-discharge speed, and thermal stability, are promising candidates in advanced power electronics technology. However, the capacitor films still face bottleneck problems of low energy storage density and high energy loss. This study presents a novel modification method designed to synergistically enhance both the breakdown strength and polarization properties of barium carbonate (BaTiO 3 , BTO)-based composite films through Zr 4+ doping and sodium bismuth titanate (Na 0.5 Bi 0.5 TiO 3 , NBT) solid-solution modification. The 0.94BaZr 0.2 Ti 0.8 O 3 -0.06NBT composite films synthesized on Pt/Ti/SiO 2 /Si substrates by sol-gel method exhibit exceptional energy storage performance. Notably, the composite films achieve an impressive recoverable energy density ( W rec ) of 62.08 J/cm 3 and a high charge-discharge efficiency( ղ ) of 85.18 % at the electric field of 6117 kV/cm. The promising results highlight the tremendous potential of the modified BTO-based composite films for transformative applications in advanced energy storage systems.