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.