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

本计画主要研究反铁电陶瓷在电与机械负载下的临界力学问题。 与大多数用于电能存储的电容器中的电介质材料相比，特殊的（例如PbZrO 3基）反铁电陶瓷由于可逆的反铁电/铁电相变而显示出高得多的能量密度，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，并形成了储能应用的基本基础。 这种体积变化会导致陶瓷内部产生复杂的应力状态，从而影响电容器的可靠性。 本计画透过实验与理论的结合，致力于建立反铁电陶瓷的相变增韧机制，以开发高效能、高可靠性的储能元件。该项目的成功将为大规模使用高功率/能量密度的反铁电电容器铺平道路。 这种电容器迫切需要用于可再生能源，如风能和太阳能。 其间歇性需要高效的能源存储技术来确保全天候的供应。 此外，该项目旨在对研究生和本科生教育产生广泛影响。 本科生，特别是那些来自代表性不足群体的学生，将通过爱荷华州州立大学现有的各种教育项目接触到这项研究。 此外，参与研究生将在夏季的几个月里在德国进行部分实验工作，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.