CAREER: SusChEM: Structure-property relationships in bi-functional battery materials

非技术描述：虽然锂离子电池一直是便携式电子产品的主要电源，但其在运输和固定市场的大规模应用可能受到有限的锂丰度的阻碍。另一方面，钠元素比锂丰富1000多倍，钠资源在国内和国际上都被认为是充足的。钠基电池化学的发展对于确保人类能源的可持续发展至关重要。这个CAREER项目研究了一种独特的双功能（阴极或阳极）钠电极材料的结构-性能关系，以阐明可能导致增强材料性能和合理设计和发现新材料的基本机制。该项目还使一个名为“电池：为过去、现在和未来提供动力”的博物馆展览能够提高公众对日常生活中无处不在的电池设备的科学和工程原理的认识，并激发公众的兴趣。技术细节：钛酸镍钠是一种独特的材料家族，可以作为阳极或阴极，由于共存的高和低氧化还原电位过渡金属。然而，这些材料的结构-性能关系仍然难以捉摸。该项目旨在发展对钛酸镍钠家族模型材料的原子和电子结构及其对离子和电子导电性的影响的基本理解。本项目通过中子/ x射线散射探针、原子模拟和电性能测量相结合的实验与计算相结合的方法，研究了钠原子的局部分布、迁移路径、离子电导率以及局部电子分布及其对电子电导率的影响。从这项工作中获得的知识对这个技术上重要和科学上有趣的材料家族有直接的影响，也有助于阐明一般混合离子-电子导体的结构-性质关系，从而导致合理的设计和发现具有优越性能的新材料。

NON-TECHNICAL DESCRIPTION: While lithium-ion batteries have been the dominant power sources for portable electronics, their large-scale applications in the transportation and stationary markets are likely to be hindered by the limited lithium abundance. On the other hand, the element sodium is more than 1000 times more abundant than lithium and sodium resources are considered adequate nationally and internationally. Development of sodium-based battery chemistry is essential in ensuring a sustainable energy future for human kind. This CAREER project studies the structure-property relationships of a unique family of bi-functional (as either cathode or anode) sodium electrode materials, in order to shed light on the fundamental mechanisms that could lead to enhanced materials performance and rational design and discovery of new materials. This project also enables a museum exhibition named "Batteries: Powering the Past, Present, and Future" to raise awareness and inspire interests of the public in the science and engineering principles of ubiquitous battery devices in our daily lives.TECHNICAL DETAILS: Sodium nickel titanates are a unique family of materials that can function either as anode or cathode due to coexistence of both high and low redox-potential transition metals. However, the structure-property relationship of these materials remains elusive. This project seeks to develop a fundamental understanding of the atomic and electronic structures and their effects on the ionic and electronic conductivity of model materials in the sodium nickel titanate family. Through an integrated experimental and computational approach combining neutron/X-ray scattering probes, atomistic simulation, and electrical property measurement, the project studies the local distribution, migration pathways, and ionic conductivity of sodium atoms, as well as the local electron distribution and its effect on the electronic conductivity. Knowledge garnered from this work has an immediate impact on this family of technologically important and scientifically intriguing materials, and also helps to shed light on the structure-property relationships in general mixed ionic-electronic conductors, thus leading to rational design and discovery of new materials with superior performance.