Ultrawide-temperature-stable high-entropy relaxor ferroelectrics for energy-efficient capacitors.

Area of Science:

• Materials Science
• Solid State Chemistry
• Energy Storage

Background:

• Developing dielectric ceramics with high energy density and broad temperature stability is crucial for advanced electrostatic capacitors.
• Conventional relaxor ferroelectric materials face limitations in achieving simultaneous high energy density and thermal stability.

Purpose of the Study:

• To engineer novel dielectric ceramics using a high-entropy strategy for enhanced electrostatic capacitor performance.
• To investigate the impact of configurational entropy on the structure-property relationships of dielectric ceramics.

Main Methods:

• High-entropy engineering was applied to transform conventional relaxor ferroelectric BT-Bi(Mg0.5Zr0.5)O3 into entropy-stabilized BT-H.
• Dual-phase cationic disorder modulation and maximization of configurational entropy were employed.
• Atomic-scale lattice heterogeneity and temperature-adaptive multiphase coexistence structures were induced.

Main Results:

• The optimized BT-H ceramics demonstrated a recoverable energy density (Wrec) of 8.9 J cm⁻³.
• Near-ideal conversion efficiency (η) of ~97.8% was achieved.
• Superior temperature stability with ΔWrec ~±9% and Δη ~±4.8% over an ultrawide range (-85–220 °C) was observed.

Conclusions:

• The high-entropy engineering strategy effectively decouples polarization configuration from thermal fluctuations.
• The entropy-mediated cocktail effect was validated, showing promise for designing advanced energy storage materials.
• Leveraging high-entropy materials offers a viable pathway for superior integrated energy storage performance in capacitors.