Mechanics of Multi-responsive Ceramics for Electrical Capacitors with High power/Energy density

本项目主要研究受电和/或机械载荷影响的反铁电陶瓷的关键力学问题。与大多数用于储能电容器的介电材料相比，特殊的（例如pbzro3基）反铁电陶瓷由于可逆的反铁电/铁电相变而显示出更高的能量密度，这表现为大量电荷和体积应变的突然发展。因此，相变使这些陶瓷对电场和机械应力都有响应，并为储能应用奠定了基础。伴随的体积变化引起陶瓷内部复杂的内应力状态，从而影响电容器的可靠性。通过实验和理论相结合的方法，本项目旨在严格建立反铁电陶瓷的新型相变增韧机制，这将导致高效、高可靠的储能器件。该项目的成功将为大规模使用具有高功率/能量密度的反铁电电容器铺平道路。可再生能源急需这种电容器，如风能和太阳能。它们的间歇性需要高效的储能技术来确保全天候的输送。此外，该项目旨在对研究生和本科教育产生广泛的影响。本科生，特别是那些来自代表性不足群体的学生，将通过爱荷华州立大学现有的各种教育项目接触到这项研究。此外，参与的研究生将在德国度过几个月的夏季，进行部分实验工作，从而获得国际经验。

This project is focused on the critical mechanics issues in antiferroelectric ceramics subjected to electrical and/or mechanical loads. Compared to most dielectric materials used in capacitors for electrical energy storage, special (e.g. PbZrO3-based) antiferroelectric ceramics display a much higher energy density due to the reversible antiferroelectric\ferroelectric phase transition, which is manifested by an abrupt development of large amounts of electrical charge and volume strain. As such, the phase transition makes these ceramics responsive to both electric fields and mechanical stresses and forms the fundamental basis for energy-storage applications. The associated volume change induces complicated internal stress states in the ceramic and thus influences the reliability of capacitors. Through an integrated experimental and theoretical approach, this project aims to rigorously establish the novel phase-transition-toughening mechanism in antiferroelectric ceramics, which will lead to highly efficient and highly reliable energy-storage devices. The success of this project will pave the way to the large-scale usage of antiferroelectric capacitors with high power/energy density. Such capacitors are urgently needed for renewable energy sources, such as wind and solar. Their intermittent nature requires efficient energy-storage technologies to ensure around-the-clock delivery. Furthermore, this project is designed to have a broad impact on both graduate and undergraduate education. Undergraduate students, especially those from underrepresented groups, will be exposed to this research through various existing educational programs at Iowa State University. In addition, participating graduate students will spend some summer months in Germany for part of the experimental work, thus acquiring international experiences.