CAREER:Understanding Interfaces in Sulfide-based All-Solid-State Na Batteries

钠离子电池比锂离子电池具有经济优势，因为它们可以使用天然丰富的钠（Na）实现类似的性能。此外，使用固体钠离子导体而不是液体电解质的固态钠电池（SSNB）提高了设备安全性，适用于电动汽车和公用电网等中型和大型储能系统。硫化物固体电解质具有上级离子导电性，因此本计画将研究硫化物固体电解质。然而，对于基于硫化物的SSNB，高界面电阻仍然是最大化性能和商业化的挑战。该研究项目将系统地研究硫化物基SSNB中两个主要界面的结构变化，以从根本上了解钠离子在这些界面上的传输。研究人员旨在解决阻碍电池高性能的关键接口问题。这项研究将与推广和教育工作相结合，如创建妇女工程网络计划和与肯塔基州科学中心的合作。这些举措将鼓励更多来自代表性不足的少数群体的学生，如K-12女孩，参加科学，技术，工程和数学（STEM）专业，并提高公众对电化学储能及其在使用清洁能源中的作用的科学意识。本项目的技术目标是从根本上了解钠阳极/硫化物SE和阴极/硫化物SE界面处的界面电阻的来源。研究人员将利用这些基础知识来设计硫化物SE，降低界面电阻，并实现具有高能量密度和稳定性的先进SSNB。第一个目的是研究卤化物掺杂的硫化物固体电解质与电极（钠阳极和阴极）的相容性，以阐明卤化物掺杂对界面电阻的影响。第二个目标旨在了解钠离子在硫化物-聚合物复合固体电解质（CSE）中的传输机制，以及在钠对称电池和SSNB中跨CSE/电极界面的传输机制。第三个目标是研究使用具有不同体积变化水平的金属硫化物阴极的硫化物基SSNB的循环性能，旨在确定SSNB在重复充电/放电循环过程中体积膨胀/收缩对界面电阻的影响。从该项目中获得的基础知识将为工程界面设计提供见解，以降低界面电阻，克服实现高容量和长寿命的先进固态钠电池的重要障碍。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Sodium-ion batteries offer an economic advantage over Li-ion batteries, as they can achieve similar performance using naturally abundant sodium (Na). Additionally, solid-state Na batteries (SSNBs) that use solid Na-ion conductors instead of liquid electrolytes improve device safety and are applicable to mid- and large-scale energy storage systems such as electric vehicles and utility grids. In this project, sulfide solid electrolytes (SEs) will be investigated for their superior ionic conductivity. However, for sulfide-based SSNBs, high interfacial resistance remains a challenge to maximizing performance and commercialization. This research project will systematically investigate structural changes at the two main interfaces in sulfide-based SSNBs to fundamentally understand the sodium ion transport across those interfaces. The investigators aim to address critical interface issues preventing high battery performance. This research will be integrated with outreach and education efforts such as creating Women Engineering Network program and a collaboration with Kentucky Science Center. These initiatives will encourage more students from underrepresented minority groups such as K-12 Girls to enroll in the science, technology, engineering and mathematics (STEM) majors, as well as increase the public’s scientific awareness on electrochemical energy storage and its role in using clean energy sources. The technical goal of this project is to fundamentally understand the origins of interfacial resistance at both Na anode/sulfide SEs and cathode/sulfide SEs interfaces. The investigators will use this fundamental knowledge to engineer sulfide SEs with reduced resistance across interface and achieve advanced SSNBs with high energy density and stability. The first objective is to investigate the compatibility of halide doped sulfide solid electrolyte with electrodes (both Na anode and cathodes) to elucidate the halide doping effects on interface resistance. The second objective aims to understand Na-ion transport mechanisms in sulfide-polymer composite solid electrolytes (CSEs) as well as across the interfaces of CSE/electrodes in Na symmetric cells and SSNBs. The third objective focuses on study the cycling performance of sulfide based SSNBs that use metal-sulfide cathodes with different levels of volume change, aiming to determine the volume expansion /contraction effects on the interface resistance in SSNBs during their repeated charge/discharge cycling process. The fundamental knowledge obtained from this project will give insights into engineering interface design to reduce the interfacial resistance, overcome an important roadblock to achieve advanced solid-state Na batteries with high capacities and long lifetimes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.