Global-optimized energy storage performance in multilayer ferroelectric ceramic capacitors

Abstract

Multilayer ceramic capacitor as a vital core-component for various applications is always in the spotlight. Next-generation electrical and electronic systems elaborate further requirements of multilayer ceramic capacitors in terms of higher energy storage capabilities, better stabilities, environmental-friendly lead-free, etc., where these major obstacles may restrict each other. An effective strategy for energy storage performance global optimization is put up here by constructing local polymorphic polarization configuration integrated with prototype device manufacturing. A large energy density of 20.0 J·cm^-3 along with a high efficiency of 86.5%, and remarkable high-temperature stability, are achieved in lead-free multilayer ceramic capacitors. The strategy provides a feasible routine from nano, micro to macro regions in manipulating local polarizations, domain-switching barriers and breakdown strength, illustrating its great potential to be generally applicable in the design of high-performance energy storage multilayer ceramic capacitors.

Fig. 1. Reasonable composition design of BNT-NN-ST ternary solid solutions via phase field simulation.

a Phase-field simulated bipolar P–E loops of (100-x-y)BNT-xNN-yST solid solutions. Only P–E loops with x and y being multiples of 10 are shown for clarity. b An enlarged P–E loop with a 50-0-50 composition as an example. Contour plots of the simulated (c) η and (d) W_rec of BNT-NN-ST solid solutions.

Fig. 2. Phase and domain structures of (1-x)BNT-0.20NN-xST ceramics.

a XRD patterns of (1-x)BNT-0.20NN-xST ceramics. b The enlarged (200) peaks. SEM images of (c) 65-20-15 ceramics and (d) 55-20-25 ceramics. e Grain size distribution of ceramics. Atomic-resolution HAADF STEM polarization vector images of 55-20-25 ceramics along (f) [100]c and (i) [110]c. (g, h, j, k) Enlarged images corresponding to the marked area.

Fig. 3. Dielectric performances, energy storage properties, breakdown characteristics, and evolution of polar structures for BNT-NN-ST ceramics.

a Dielectric constant and dielectric loss as a function of temperature for 55-20-25 ceramics. P–E loops measured at (b) 300 kV·cm⁻¹ and (c) their respective E_b for (1-x)BNT-0.20NN-xST ceramics. d W_rec and η, e Weibull plots of E_b, f AGS and E_b for (1-x)BNT-0.20NN-xST ceramics. g The Landau energy profiles, h Random field distribution, and i, simulated domain structures of 55-20-25-Mn ceramics. Different phases and various polar directions in the same phase are denoted by different colors.

Fig. 4. Energy storage properties of the 55-20-25-Mn MLCC devices.

a Digital images of the MLCCs and SEM images of the cross-section area with corresponding element distribution. b P–E loops of 55-20-25-Mn MLCC under various electric fields. Comparison of the energy storage properties for 55-20-25-Mn MLCC and state-of-the-art other MLCCs at (c) room temperature and (d) 100–150 °C. e cycle number-dependent W_rec and η under 900 kV·cm⁻¹. f Calculated W_dis and t_0.9.