Ultrahigh energy storage density in (Bi0.5Na0.5)0.65Sr0.35TiO3-based lead-free relaxor ceramics with excellent temperature stability

Simultaneously enhanced energy density and discharge efficiency of (Na0.5Bi0.5)0.7Sr0.3TiO3-La1/3(Ta0.5Nb0.5)O3 lead-free energy storage ceramics via grain inhibition and dielectric peak flattening engineering

“…The negatively charged point defects ( V ′ Na and V ′′ Sr ) and the positively charged point defects will form the neutral defect complexes and , which could inhibit the grain growth, decrease the oxide ion conductivity and further improve the E b . 29,31 (2) In general, the valence of Ti ions fluctuates easily (Ti 4+ ↔ Ti 3+ + e − ), and therefore oxygen vacancies will be generated in order to sustain the overall charge neutrality. 32 As a result, the substitution of high-valence Nb 5+ and Ta 5+ into Ti 4+ can repress the formation of oxygen vacancies with positive charges and further reduce the number of oxygen vacancies, thus playing a role in stabilizing the Ti 4+ ions.…”

Simultaneous Enhancement of Energy Storage and Hardness Performances in (Na0.5Bi0.5)0.7Sr0.3TiO3-Based Relaxor Ferroelectrics Via Multiscale Regulation

“…According to the above equations, it can be deduced that the simultaneous achievement of polarization difference (Δ P = P max – P r ) and breakdown electric field ( E b ) is desirable for enhancing the W rec of capacitors. However, several potential factors, , such as delayed polarization saturation and good hardness characteristics, must also be addressed to obtain high W rec and meet the reliability of practical applications.…”

“…This method is widely adopted to inhibit the forming of the long-range polar order and suppresses the early polarization saturation in NaNbO 3 (NN)-, BaTiO 3 (BT)-, and BNST-based materials with low T m , but it is still difficult to establish the connection between macroscopic energy storage performances and mesoscale domain configuration. (iii) Introducing the full d 10 ions at B-site and inducing highly dynamic PNRs via doping to decrease ferroelectricity (low P r ). , These methods will result in decreased ferroelectricity and polarization saturation, but the physical mechanism and specific process of delayed saturation polarization are still not well understood and remain controversial.…”

“…According to the above equations, it can be deduced that the simultaneous achievement of polarization difference (ΔP = P max − P r ) and breakdown electric field (E b ) is desirable for enhancing the W rec of capacitors. However, several potential factors, 8,9 such as delayed polarization saturation and good hardness characteristics, must also be addressed to obtain high W rec and meet the reliability of practical applications. Bi 0.5 Na 0.5 TiO 3 (BNT), as one of the representative dielectric ceramics, has attracted wonderful attention in the field of highperformance dielectric capacitors due to its strong ferroelectric (large P max > 40.00 μC/cm 2 ) and broad operating temperature range.…”

Realizing high energy density and efficiency simultaneously in (Bi0.5Na0.5)0.7Sr0.3TiO3-based ceramics via introducing linear dielectric CaTiO3

“…Of particular significance, Zhu et al realized an ultrahigh W rec of 8.46 J cm −3 with an excellent η of 85.90% in 0.90(Bi 0.5 Na 0.5 ) 0.65 Sr 0.35 TiO 3 -0.10Bi(Mg 0.5 Zr 0.5 )O 3 bulk ceramics and revealed that the delayed polarization saturation stems from inducing a local random field and increasing the number of highly dynamic PNRs. 16 In addition, introduction of ions with low polarizability or a full d 10 configuration into B-sites in some studies 17 was beneficial to suppress obvious premature saturation polarization in relaxor ferroelectrics with weak ergodicity. Unfortunately, the physical mechanisms behind these macroscopic performance parameters are still not well understood and remain controversial, and it is also difficult to establish the correlation between macroscopic properties and mesoscopic domain configurations.…”