陶瓷织构化调控NaNbO3基反铁电体的击穿与极化行为及其储能特性优化

小型化和轻量化是储能电介质电容器的发展趋势，因此开发具有高储能密度的新型电介质材料成为近年关注的焦点。目前，电介质储能材料面临的最大挑战是低的储能密度，而难以同时获得高的击穿强度和极化强度是瓶颈所在。针对上述问题，本项目提出以NaNbO3（NN）基反铁电体为模型体系，研究陶瓷织构化对击穿行为、极化行为和储能密度的影响规律。首先通过掺杂改性提高NN基陶瓷的反铁电稳定性；然后通过陶瓷织构化和界面工程调控“砖块状”晶粒的形貌，以及陶瓷界面特性和缺陷分布；进一步通过取向工程研究织构陶瓷的电击穿行为和反铁电—铁电相变行为，阐明织构陶瓷的击穿机制和极化强度的影响机制；最后对织构陶瓷的储能特性进行评估和优化。通过上述研究，构建反铁电织构陶瓷的击穿强度和极化强度的协同提升模型和方法，为高性能电介质材料的开发提供科学依据和指导。

Miniaturization and lightweight are the trends of dielectric capacitors, which arouse the focus on developing novel dielectric materials with high energy storage density. At present, the state-of-the-art dielectric materials are facing the challenge of low energy storage density, due to the difficulty to simultaneously achieve high breakdown strength and polarization. In view of the above problems, the NaNbO3 (NN) will be selected as the research objects and models in this project, to study he effect of ceramic texturing on breakdown/polarization behavior and energy storage density. Firstly, the antiferroelectric stability of NN-based ceramics will be improved by delicately doping; then, the morphology of "brick like" grains, the interface characteristics and defect distribution will be regulated by ceramic texturing and interface engineering; furthermore, the breakdown behavior and antiferroelectric-ferroelectric (AFE-FE) phase transition behavior of textured ceramics will be study through orientation engineering, to elucidate the mechanism of breakdown and improved polarization of textured ceramics; finally, the energy storage performance will be evaluated and optimized. Through the above research, new model and method of synergistically improving the breakdown strength and polarization of antiferroelectric ceramics will be established, which may provide a good paradigm for developing new high-performance dielectric materials.