New pyrochlore La2Zr2O7 ceramics with ultra-high breakdown electric field strength and energy storage efficiency

Abstract

This study investigates the potential of pyrochlore-type La₂Zr₂O₇ (LZO) ceramics as lead-free dielectric energy storage materials. LZO ceramics were synthesized using a traditional solid-phase sintering method and exhibited exceptional energy storage properties. The breakdown field strength of LZO ceramics reached an impressive 1350 kV cm⁻¹, with a maximum polarization strength of 6.29 μC cm⁻² and a minimal residual polarization strength of 0.31 μC cm⁻². The effective energy storage density of LZO was measured at 3.89 J cm⁻³, with an outstanding energy storage efficiency of 89.78%. Furthermore, over-damped pulse discharge experiments revealed that LZO ceramics can release 90% of the energy density in just about 1.1 μs, indicating an extremely fast charge/discharge rate. Temperature and frequency stability tests demonstrated minimal fluctuations in energy storage density and efficiency, highlighting the robustness of LZO ceramics across a wide range of environmental conditions. The comprehensive energy storage characteristics of LZO ceramics, combined with their high breakdown field strength and efficiency, indicate their significant research value and potential for applications in high-pressure resistant and high-efficiency energy storage ceramics. This work lays a solid foundation for future research in the field of pyrochlore-type A₂B₂O₇ energy storage ceramic systems, positioning LZO ceramics as promising candidates for advanced energy storage applications.