Multi-objective collaborative design optimized highly efficient energy capacitive lead-free relaxor ferroelectrics

Abstract

Cutting-edge energy storage ceramics as the core components in pulse power capacitors are indispensable for advanced electronic systems. Although improved energy storage performance has been realized to a certain extent, how to effectively address the mutual restriction among different functional parameters to further gain highly efficient performances is still an issue. Here, we show that, via multi-objective collaborative design, a high energy storage density of ∼6.82 J cm⁻³ and efficiency of ∼90%, concurrent with an ultrahigh energy storage potential of ∼0.01624 μC cm⁻², as well as superior temperature/frequency/cycling stabilities and satisfactory charging–discharging performance are achieved in lead-free relaxor ferroelectrics, showing great application potential and performance merits compared with previous investigations. The giant highly efficient energy storage performance can be mainly attributed to multiphase polar nanoregion coexistence with multiple local distortions and tailoring of the grain size and band gap, designed by a multi-objective collaboration strategy. These favorable features enable substantially high polarization, ultralow remnant polarization, delayed polarization saturation, minimized hysteresis, and enhanced breakdown strength. This work demonstrates that multi-objective collaboration design is an adjustable but effective strategy for solving the mutual restriction among different functional parameters to design high-performance capacitive energy storage dielectrics.