Solid-Solid Interfacial Chemistry in Energy Storage and Conversion Systems

能源需求的大幅增长需要安全、大规模、可持续的未来能源转换和储存设备，这些设备通常由固体材料制成。定义不清的界面化学很可能是阻碍这些器件的性能和寿命的根源。该提案涉及下一代能源设备--全固态钠离子电池和钙钛矿型太阳能电池--界面的基本过程。我们将电化学与多学科的光谱和显微分析相结合，以询问电极和固体-电解液(或钙钛矿)界面上发生的化学，特别是在器件运行期间。微扰允许在设备运行的不同阶段明确地解释界面化学特性。*我们的长期目标是彻底了解固体-固体电化学界面的结构-性能关系，并最终将材料合成和加工相结合，以实现优化的界面设计，从而提高器件性能。我们通过开发现场测量工具来启动这项研究计划，以实现两个短期目标。*1.控制全固态钠电池(ASSB)电极/电解液界面。ASSB利用丰富的资源，提高电池的安全性。固体电解液(SE)和电极界面的降解阻碍了电池的循环寿命。循环过程中SE/电极界面的识别和转变仍然难以捉摸。我们将研究硫代磷酸钠固体钠离子导体(一种潜在的ASSB固体电解质材料)在电池运行过程中电极表面的(化学和机械)稳定性。这项工作将揭示与电池短路和容量衰减相关的界面分解机制。这些启示将指导稳定的SES或界面保护材料的分子设计，并有助于阐明界面工程方案。2了解钙钛矿型太阳能电池(PSC)的滞后现象。钙钛矿型太阳能电池表现出出色的能量转换效率。设备迟滞的结构起源尚不清楚。对器件稳定性的要求很高。我们将运用我们在原位界面表征方面的专业知识，并探讨导致器件滞后的两个潜在原因：(1)钙钛矿/氧化物相互作用和内建电位导致的界面电荷陷阱，以及(2)钙钛矿结构中的离子在电势下的迁移率。研究结果将为具有优异稳定性的高性能PSC的材料和界面设计提供洞察。*本计划中开发的现场界面测量方法将作为一个可移植的平台，用于研究其他下一代能源设备，如高能固态电池(多价电池)、无铅PSC和其他新兴的能量存储和转换系统。**

The substantial growth of energy demand requires safe, large scale, and sustainable future energy conversion and storage devices, which are often made of solid materials. Poorly defined interfacial chemistries are likely the origins that hinder the performance and lifetime of these devices. This proposal addresses the fundamental processes at interfaces of the next-generation energy devicesall-solid sodium-ion batteries and perovskite solar cells. We combine electrochemistry with multi-disciplinary spectroscopic and microscopic analysis to interrogate chemistry occurring at electrode and solid-electrolyte (or Perovskite) interface, particularly during device operation. Perturbations allow for explicit interpretation of interfacial chemical identity at different stages of device operation. ******The long-term objective is a thorough understanding of the structure-property relationship at the solid-solid electrochemical interfaces, and ultimately combine material synthesis and processing to enable optimized interfacial design for promoted device performances. We initiate this research program by developing in-situ measurement tools to realize two short-term objectives. ******1. Control the electrode/electrolyte interface for All-solid Sodium Battery (ASSB). ASSB utilize abundant resources and improve battery safety. Degradation at the solid electrolyte (SE) and electrode interface hinders the battery cycle life. The identity and transformation of the SE/electrode interface during cycling remain elusive. We will investigate the (chemical and mechanical) stabilities of sodium thiophosphate solid Na-ion conductor a potential solid electrolyte material for ASSBat the electrode surfaces during battery operation. This work will reveal the mechanisms of interfacial decomposition that associated with battery shorting and capacity fade. These implications will guide the molecular design of stable SEs or interfacial protection materials, and shed light on interfacial engineering protocols.******2 Understand Hysteresis of Perovskite Solar Cell (PSC). Perovskite solar cells show outstanding energy conversion efficiencies. Structural origins of device hysteresis remain unclear. Device stabilization is highly desired. We will implement our expertise in in-situ interfacial characterization and interrogate the two potential reasons for the device hysteresis: (1) interfacial charge trapping due to Perovskite/oxide interaction and built-in potentials, and (2) ion mobility in Perovskite structure under electrical potential. Results will provide insights into the material and interface design for high-performance PSCs with excellent stability.******The in-situ interfacial measurement methods developed in this program will serve as a transportable platform to study other next-generation energy devices such as high energy solid state batteries (multivalent batteries), lead-free PSCs, and other emerging energy storage and conversion systems.**