[Bi0.5(Na0.4-xLixK0.1)]0.96Sr0.04Ti0.975Ta0.025O3 lead-free RELAXOR ceramics with the enhanced recoverable energy density

The high recoverable energy density (W-rec) of 1.83 J/cm(3) was achieved at 120 kV/cm by simply introducing 0.050 mol. % Li+ ions into the A-site of Bi-0.5(Na0.4K0.1)(]0.96)Sr0.04Ti0.975Ta0.025O3 lead-free relaxor ceramics. Bi-0.5(Na0.4-xLixK0.1)](0.96)Sr0.04Ti0.975Ta0.025O3 (BNKSTT-100xLi) ceramic samples were prepared by solid-state reaction method. The influence of Li+ ions on structure and electrical properties was analyzed in detail. XRD patterns and Raman spectra of these samples were revealed a pure perovskite-type structure. BNKSTT-100xLi ceramics exhibited an obvious relaxor characteristic with the downshift of TF-R to ambient temperature. J - E loops confirmed the relaxor ferroelectric like nature. Leakage current density was proved to decrease with the increasing Li+ ions concentration. At the composition x = 0.050, remnant polarization (P-r) kept steady while maximum polarization (P-max) and breakdown strength (DBS) increased obviously, which was beneficial to the enhancement of recoverable energy density.