High-efficiency lead-free BNT-CTT perovskite energy storage ceramics under high electric field

The energy issue is currently a highly significant topic of concern, and the development of environmentally friendly and high-performance lead-free energy storage devices is fundamental to solving energy problems, but it also poses challenges. Lead-free environmentally friendly (Bi 0.5 Na 0.5 )TiO 3 [BNT] has attracted widespread attention due to its high polarization, but its low efficiency greatly affects its practical application. In this study, 1- x (Bi 0.5 Na 0.5 )TiO 3 - x Ca(Ti 0.8 Ta 0.16 )O 3 [1- x BNT- x CTT]ceramics were prepared to investigate the relationship between their microstructure and macro energy storage properties. With the introduction of CTT, the long-range order was broken, reducing the grain size; the introduction of high bandgap energy Ta 2 O 5 reduced residual polarization and improved the energy storage efficiency of the ceramics. Finally, high energy storage ( W rec  = 3.01 J/cm 3 ) and high energy storage efficiency ( ƞ  = 90 %) were achieved in the 0.7BNT-0.3CTT ceramics, and the breakdown field strength was increased to 350 kV/cm, with excellent discharge performance ( P D of 28.97 MW/cm 3 , t 0.9 of 1.9 μs). This study explores lead-free relaxor ferroelectric energy storage capacitors with high efficiency under high electric fields, providing a new approach to optimize the energy storage performance of ceramic energy storage devices.