High-energy storage performance in lead-free (0.8-x)SrTiO3-0.2Na0.5Bi0.5TiO3-xBaTiO3 relaxor ferroelectric ceramics

Progress, Outlook, and Challenges in Lead‐Free Energy‐Storage Ferroelectrics

“…Based on this, systematic work has been first set about by adding BT to form a series of (0.8‐ x )SrTiO 3 0.2Na 0.5 Bi 0.5 TiO 3 ‐ x BaTiO 3 ((0.8‐ x )ST‐0.2NBT‐ x BT) ceramics, then by B‐site substitution to form (1− x )(0.45SrTiO 3 0.2Na 0.5 Bi 0.5 TiO 3 0.35BaTiO 3 )‐ x SnO 2 (STNBTBT‐Sn x ) ceramics. Consequently, ESD of 1.78 J cm −3 has been reached for enhanced ε in the first step and a higher value of 2.25 J cm −3 with much slimmer P – E loops has been finally achieved for lower tanδ and higher E B due to more homogeneous grain size . The dielectric properties' variation with the ESD's increasing process has all been illustrated in Figure , and the improvement of polarization and E B can be clearly observed, respectively, judging from the P – E loop by the addition of BT and SnO 2 .…”

“…Consequently, ESD of 1.78 J cm −3 has been reached for enhanced ε in the first step and a higher value of 2.25 J cm −3 with much slimmer P-E loops has been finally achieved for lower tanδ and higher E B due to more homogeneous grain size. [39,40] The dielectric properties' variation with the ESD's increasing process has all been illustrated in Figure 7, and the improvement of polarization and E B can be clearly observed, respectively, judging from the P-E loop by the addition of BT and SnO 2 . To optimize η of ST-NBT-BT system, which is the same important parameter as ESD in energy materials, favorable solid solution of (1−x) SrTiO 3 -x(0.65BaTiO 3 0.35Bi 0.5 Na0.5TiO 3 ) ((1−x)ST-x(0.65BT-0.35BNT)) with η over 90% caused by enhanced saturated polarization has been reported by Yang et al [41] Na + , Bi 3+ , and Ti 4+ in ST-NBT-BT system have been all partly substituted by Li + , La 3+ , and Zr 4+ , respectively, in the further work to increasing relaxation degree and T c , and this has worked.…”

“…Reproduced with permission. [39] Copyright 2018, Elsevier. e) Temperature-dependent permittivity and dielectric loss and f) P-E loops of ST-NBT-BT-0.07Sn ceramic.…”

“…Better performances of RFE and AFE than normal FE have been revealed of shrinkage of E c and stretch of P m −P r and sometimes delayed polarization saturation in P-E loops, resulting in both increasing ESD and η. [23,25,[38][39][40][64][65][66][67][68][69]71] In the process of development for studying energy storage dielectrics/ferroelectrics, computer simulation has played an increasing important role, especially in analyzing the effects of interface engineering. Despite the FES techniques, phase field simulation and first principles calculation have both provided evidence for experimental data and made predictions for discovering new materials.…”

Grain‐size–dependent dielectric properties in nanograin ferroelectrics

“…It has been reported that the dielectric breakdown strength dominates the energy performance in ferroelectric materials compared to the dielectric permittivity, especially under an ultrahigh electric field from the experimental aspect . Furthermore, the energy storage efficiency is considered one of the most important indicators of ferroelectric energy storage ceramics, which is why relaxor ferroelectric ceramics are attracting increasingly more attention in applications of energy storage devices . Such energy storage densities can be easily calculated from electric hysteresis loops.…”