Energy storage performances of La doped SrBi5Ti4FeO18 films

Developing environment-friendly dielectric film capacitors with excellent energy storage performances is a valuable and challenging task for current electronic devices. This work designs a five-layered lead-free SrBi5-x- LaxTi4FeO18 (SBLTF-x) relaxor ferroelectric films with higher polarization and breakdown genes. Interestingly, high content of La3+ ions substitution for Bi3+ ions in SBLTF-x films enter not only pseudo-perovskite (SrBi3-Ti4FeO16)(2-)layers but also (Bi2O2)(2+) layers. The relaxation behavior and the electric breakdown strength are improved by layer engineering including the inter-layer distortion and interaction between pseudo-perovskite and (Bi2O2)(2+) layers, thus achieving superior energy storage performances. Ultrahigh recoverable energy storage density of 142.8 J/cm(3) and a high efficiency of 80% were obtained simultaneously under 3085 kV/cm in SBLTF-1.00 film. Moreover, the film also behaves excellent stability of temperature (-20-120celcius), frequency (0.05 k-20 kHz) and cycling (10(8) cycles). This work not only develops a promising environmentally benign candidate for dielectric energy storage capacitors, but also provides an effective strategy to regulate energy storage performances by layer engineering in Aurivillius-type bismuth layer-structured ferroelectric films.

Automated summary

This study designs a five-layer lead-free material for dielectric film capacitors, which shows improved relaxation behavior and breakdown strength through layer engineering, achieving superior energy storage performances.