Capacitive energy-storage and electromechanical properties of aerosol-deposited 0.5BaZr0.2Ti0.8O3–0.5Ba0.7Ca0.3TiO3 films

Integrating functional ceramic thick films onto metal substrates for advanced electronic applications is challenging due to the high sintering temperatures. To address this issue, low-temperature processing methods such as aerosol deposition (AD) offer an effective solution. In this study, lead-free 0.5Ba(Zr 0.2 Ti 0.8 )O 3 –0.5(Ba 0.7 Ca 0.3 )TiO 3 (BZT–BCT) thick films were prepared on low-cost stainless-steel substrates using the AD method. The as-deposited films exhibited a dense microstructure and excellent adhesion to the substrate. After deposition, the films were annealed at 500°C and 800°C. The films annealed at 800°C demonstrated enhanced ferroelectric behavior compared to both the as-deposited films and those annealed at 500°C. These films also exhibit a high dielectric breakdown strength exceeding 1400 kV·cm −1 , making them promising for energy storage applications. The recovered energy density and energy efficiency reach 9.5 J·cm −3 and 84%, respectively, at 1500 kV·cm −1 . Moreover, the recovered energy density demonstrated excellent electric-field cycling stability up to 100 million cycles, as well as thermal stability from −50°C to 200°C at 400 kV·cm −1 . The field-induced strain response of the films annealed at 800°C demonstrated an electromechanical performance with a maximum strain of 0.05% at 350 kV·cm −1 , corresponding to a converse effective piezoelectric coefficient of 15.5 pm·V −1 . The dominating factor for such a relatively low value is most likely the fine microstructure. Overall, the results highlight the potential of integrating lead-free ceramic films onto low-cost stainless-steel substrates to form functional structures, especially for energy storage applications, where good thermal and electrical cycling stability is essential.