Mechanical Modulation of Antiferroelectric Na1+xNbO3 for Energy Storage Systems

能量存储是一项关键的工程挑战，需要一套可能的技术解决方案来满足各种应用的不同要求，包括能量和功率密度、热稳定性和疲劳响应等。在这里，无铅反铁电材料因其特殊的功率密度和可调谐电场诱导的fe - fe相变而成为高能量密度固态储能系统的有希望的候选者。然而，尽管如此，仍有许多限制，包括相对较低的能量密度和通过Na挥发引起的a位非化学计量的电位处理。重要的是，这类材料的机械本构行为仍然没有得到很好的理解，特别是观察到的机械性能的多长度尺度物理起源，这是在各种应用中使用的关键问题，例如薄膜，在操作过程中施加显著的应力。因此，拟建项目的主要目的是实验研究NaNbO3的力学行为作为a位化学计量学的函数，其中应力对铁弹性响应、相边界和能量存储能力的影响将直接表征。使用尖端的应力依赖光谱和衍射技术，将获得对观察到的性质的微观起源的独特见解。

The storage of energy is a critical engineering challenge that requires a suite of possible technological solutions to meet the varied requirements of numerous applications, including energy and power density as well as thermal stability and fatigue response, amongst others. Here, lead-free antiferroelectric materials are promising candidates in high energy density solid-state energy storage systems for their exceptional power density and tunable electric field induced AFE-FE phase transition. Despite this, however, there are a number of limitations, including the relatively low energy density and potential processing induced A-site nonstoichiometry through Na volatilization. Importantly, the mechanical constitutive behavior of this material class remains not well understood, in particular the multi-length scale physical origins of the observed mechanical properties, which is a critical issue for utilization in various applications, such as thin films, that apply significant stresses during operation. As such, the primary aim of the proposed project is the experimental investigation of the mechanical behavior of NaNbO3 as a function of A-site stoichiometry, where the influence of stress on the ferroelastic response, phase boundaries, and energy storage capabilities will be directly characterized. Using cutting edge stress-dependent spectroscopy and diffraction techniques, a unique insight into the microscopic origins of the observed properties will be obtained.