Achieving high comprehensive energy storage properties of BNT-based ceramics via multiscale regulation

It is difficult to obtain high polarization strength and high breakdown strength synchronously, resulting in the drawback of lower energy storage density, which inhibits commercial application of energy storage materials. We have successfully prepared (1-x)(0.93Bi_0.5Na_0.5TiO₃-0.07CaSnO₃)-xSrTiO₃ (BNT–CS–xST) ceramics by solid-state method. The presence of polymorphic nanodomains and the large electric displacement generated by the high charge Sr²⁺-Sr²⁺ ion pairs help to delay saturation polarization (P_m ∼ 48.64 μC/cm² at 315 kV/cm). In addition, the breakdown field strength (E_b) is increased by grain refinement and increasing the band gap. It is noteworthy that a high recoverable energy storage density (W_rec = 4.2 J/cm³) and a great efficiency (η = 88%) were achieved simultaneously in BNT–CS–0.5ST ceramic. Moreover, excellent charge-discharge performance was also achieved, with a discharge energy density W_d of 2.2 J/cm³, a current density C_D of 1724 A/cm² and a power density P_D of 250 MW/cm³. The study demonstrates that the great potential of BNT–CS–xST ceramics in power storage devices and provides an effective strategy for designing ceramics dielectric capacitors with excellent performance.     

Superior energy storage performance of all-inorganic flexible antiferroelectric-insulator multilayer thin films

In this work, we develop an all-inorganic flexible capacitor films that by growing antiferroelectric Pb_0.94(Li_0.5Al_0.5)_0.06ZrO₃ (PLAZO) and insulating Al₂O₃ (AO) layer by layer on the flexible mica substrates. The results show that the low-annealing temperature below 600°C endows the PLAZO films to have low polarization loss and high breakdown strength, conversely, the high-annealing temperature above 650°C gives rise to large maximum polarization at the expense of breakdown strength. The insulating AO layers are introduced to reconcile the polarization and breakdown strength, achieving a remarkable improvement in the energy storage density of 41.78 J/cm³ with an efficiency of 91.2% in the AO/PLAZO/AO/PLAZO/AO (APAPA) multilayer films, which can be attributed to the significant improvement in breakdown strength and suppression of polarization loss by introducing AO insulator layer. Moreover, the energy storage performance of the APAPA flexible thin film capacitors possesses excellent frequency stability as well as bending cyclic endurance.