Electrode/Electrolyte Interfaces in High-Voltage Aqueous Alkali-Ion Batteries

以可承受的成本进行能源储存已成为能源部门面临的一个具有挑战性的问题。它对于从电动汽车到可再生能源的电网存储等广泛应用至关重要。与目前使用有机溶剂的锂电池相比，使用水性（水基）电解质的电池可能更耐用，更不容易发生热失控。许多这些储能应用需要高能量密度和安全的热控制系统。水电解质可以解决这一问题，并且由于其低成本和高功率而有利于储能。然而，与使用有机电解质的锂离子电池相比，目前的水电池技术能量密度不够低，电压输出更窄。本研究项目的目的是扩大水电池的电压操作窗口。本研究将使用模型薄膜系统，并结合一套先进的原位同步加速器x射线散射和光谱方法来研究电极/电解质界面，这被认为是在这些系统中实现高电压的关键。除了在科学方面的进步，该项目还通过俄勒冈州立大学的约翰逊奖学金促进本科生参与研究，并通过俄勒冈州立大学青年科学与工程暑期体验项目开展STEM推广，该项目涉及初中和高中的预科学生。碱离子电池（AAIBs）在成本、安全性和功率方面都是大规模电化学储能的理想选择。与使用有机电解质的锂离子电池相比，aaib的主要缺点是有限的1.23电压窗，超过该电压窗会发生水分解反应，从而产生氢气和/或氧气。虽然一些成功的案例表明，使用盐包水电解质可以获得一些含水锂离子化学物质的高压（超过3v），但这些知识尚未转化为其他碱离子化学物质，如钠离子或钾离子。这个项目的目标是使用定义良好的水性锂离子电池薄膜系统和原位同步加速器x射线技术来研究阳极和阴极固体电解质界面的形成、结构和组成。这些知识可以用于设计高压和长循环寿命的水电池。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Energy storage at an affordable cost has emerged as one of the challenging issues for the energy sector. It is critical for a wide range of applications ranging from electric vehicles to grid storage of renewable energies. Batteries that use an aqueous (water-based) electrolyte have the potential to be more durable and less prone to thermal runaways than current lithium batteries that use an organic solvent. Many of these energy storage applications require high energy density with safe, thermal control of the system. The aqueous electrolyte can solve this problem and also be beneficial for energy storage due to its low cost and high power. However, current aqueous battery technology has an insufficiently low energy density and a narrower voltage output compared to lithium-ion batteries using organic electrolyte. The aim of this research project is to expand the voltage operating window of aqueous batteries. This research will use model thin film systems and combine a suite of advanced in-situ synchrotron X-ray scattering and spectroscopy methods to study the electrode/electrolyte interfaces, which is posited to be the key to enable high voltage in these systems. In addition to advancement in science, the project also promotes the participation of undergraduate students in research through Oregon State University’s Johnson Scholarship and conducts STEM outreach through the OSU Summer Experience in Science & Engineering for Youth Program involving pre-college students in middle school and high school.Aqueous alkali-ion batteries (AAIBs) are promising candidates for large-scale electrochemical energy storage in terms of cost, safety, and power capability. Compared to lithium-ion batteries using organic electrolyte, the main drawback of AAIBs is the limited 1.23 voltage window, beyond which the water splitting reaction happens and consequently hydrogen and/or oxygen gases are produced. Although some successful cases have demonstrated that using water-in-salt electrolyte can obtain high-voltage (more than 3 V) for some aqueous lithium-ion chemistries, such knowledge has not been transformed to other alkali ion chemistries such as sodium or potassium-ion. The goal of this project is to use well-defined thin film systems of aqueous lithium-ion batteries and in-situ synchrotron X-ray techniques to study the formation, structure and composition of solid-electrolyte interphases at the anode and cathode. Such knowledge can be used to design aqueous batteries with high-voltage and long cycling life.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.