Collaborative Research: Zeolite Thin Films as Efficient and Robust Ion Exchange Membranes in Redox Flow Batteries for Renewable Energy Storage

董，君航/ Murad， sohail缺乏经济高效的储能设备是可再生太阳能和风能广泛利用的主要障碍之一。氧化还原液流电池（RFB）因其出色的安全性、高容量、高效率、模块化和小环境足迹而成为一个有吸引力的选择；然而，在目前的发展状态下，由于离子交换膜（IEM）的效率低下，它在商业上不可行，这是决定其成本效益、能源效率和电池寿命的关键因素。rfb的IEMs的研究和开发工作主要集中在聚合物基材料上。这些材料有根本的缺陷，与它们的聚合物性质有关，与离子交叉和在rfb的高浓度电解质溶液中的化学不稳定性有关；因此，需要用新材料制造替代集成电路。本项目的目标是探索纳米多孔沸石薄膜作为一种新型的高效耐用的rfb IEMs。一个关键的目标是了解沸石膜中质子传导和场驱动离子传输的机制。本文主要研究了Fe/Cr RFB和全钒RFB两种RFB系统的硅质mfi型沸石膜。具体目标包括：(1)合成具有不同厚度、取向和框架组成的MFI沸石膜，并研究这些结构和化学性质对RFBs膜性能的影响；（ii）实验研究质子和相关金属离子在外加电场和不外加电场的输运性质；(3)对电场驱动和化学电位梯度驱动的离子传输过程进行分子模拟。沸石膜的输运受？水合质子?在本质上是非离子的亚纳米沸石通道中，与水合离子聚合物中的质子跳跃过程有着根本的不同。本研究将采用纳米多孔无机膜，特别是晶体沸石膜，作为rfb的新一代高效坚固的IEMs。该项目将通过实验研究和分子动力学模拟的协同努力，推进沸石膜中离子传输的基础知识。模拟将指导确定最有前途的膜结构和化学性质的努力。更广泛的影响：如果成功，这项研究可能会指导可再生能源间歇性能源存储设备的设计。所开发的膜在能源生产和环境保护方面也具有潜在的应用前景。对沸石纳米孔中电场驱动离子传输机制的更完整的基本理解将对膜科学做出重大贡献。该项目涉及实验和理论研究，将为研究生和本科生提供机会。已制定计划，将研究成果纳入现有课程，并让来自不同学术和种族背景的本科生参与。两个pi都通过研究项目和研讨会上的演讲，开展了涉及高中生和本科生的外展活动。

1263860 / 1263707 Dong, Junhang / Murad, SohailThe lack of economical and efficient energy storage devices is one of the major hurdles to the widespread utilization of renewable solar and wind energy. The redox flow battery (RFB) is an attractive option because of its excellent safety, high capacity, high efficiency, modularity, and small environmental footprint; however, in its current development state it is not commercially viable largely because of inefficiencies in the ion exchange membrane (IEM), which is a key factor determining its cost effectiveness, energy efficiency, and battery lifetime. Research and development efforts on IEMs for RFBs have largely focused on polymer-based materials. These materials have fundamental deficiencies, associated with their polymeric nature, related to ion crossover and chemical instability in high concentration electrolyte solutions of RFBs; therefore, alternative IEMs fabricated from new materials are required. The goal of this project is to explore nanoporous zeolite thin films as a new class of highly efficient and durable IEMs for RFBs. A key objective is to understand the mechanisms of proton conduction and field-driven ion transport in the zeolite membranes. The research will primarily focus on the siliceous MFI-type zeolite membranes for two model RFB systems including the Fe/Cr RFB and the all-vanadium RFB. The specific objectives include: (i) synthesizing MFI zeolite membranes with different thickness, orientation, and framework composition and investigating the effects of these structural and chemical properties on the membrane performance in RFBs; (ii) experimentally studying the transport properties for proton and relevant metal ions with and without applied electric fields; and (iii) performing molecular simulations of the electrical-field-driven and chemical-potential-gradient-driven ion transport processes. Zeolite membrane transport is governed by the field-driven diffusion of ?hydrated protons? in essentially non-ionic subnanometer zeolitic channels and is fundamentally different from the proton hopping process in the hydrated ionic polymers. This research will employ nanoporous inorganic membranes, particularly the crystalline zeolite membranes, as a new generation of highly efficient and robust IEMs for RFBs. The project will advance fundamental knowledge on ion transport in the zeolite membranes through synergistic efforts involving experimental studies and molecular dynamics simulations. Simulations will guide efforts to determine the most promising membrane structural and chemical properties. Broader Impacts: If successful, this research may guide the design of storage devices for intermittent energy from renewable sources. The membranes developed will also have potential applications energy production and environmental protection. A more complete fundamental understanding of the electrical field-driven ion transport mechanism in zeolitic nanopores will be a significant contribution to membrane science. The project involves experimental and theoretical studies that will provide opportunities for graduate and undergraduate students. Plans have been made to incorporate the research findings into existing courses and to include undergraduate participation from diverse academic and ethnic backgrounds. Both PIs have outreach activities involving high school students and undergraduate students through research projects and presentations at seminars.