Experimental and Modeling Studies on Redox Flow Batteries

鉴于不断增长的人口和工业化以及向可再生能源的转变，对能源存储系统的需求从未如此之高。这些系统在特定时期储存多余的能量，并在其他时间按需释放，使电网能够更好地将可再生能源与基本负荷能量结合起来，并且对干扰更强。不幸的是，目前可用的存储方法很少，因此全球只有不到10%的电力来自储能。电化学方法由于其无公害、快速响应、高效率、灵活性、便携性和低维护等优点，有望填补这一空白。在这些方法中，氧化还原液流电池（RFB）脱颖而出。和其他电池一样，电极被放在单独的隔间里。与传统电池不同的是，反应物溶解在储存在外部罐中的液态电解质中，并连续泵送通过发生氧化还原反应的隔间。这些特性使rfb优于其他电池——独立控制能量和功率，固有安全性，快速可逆的氧化还原反应，无固态效应，易于热管理，不过热，不电解质分解，寿命长。然而，两个主要因素阻碍了它们的采用-高安装成本和耐用性问题。这项研究计划的重点是提高性能和耐用性，同时降低两种相对较新的系统-锌-铈和钒-铈rfb的成本。Ce3+/Ce4+反应发生在正极，而Zn/Zn2+和V2+/V3+反应发生在负极。这些系统非常有前途，因为它们比其他rfb获得更高的电池电压和潜在的更高的能量和功率。拟议的研究将包括i)旨在抑制寄生副反应和提高电池性能和耐久性的实验规模实验和ii)开发每个电池的综合模型。该研究的新方面是在两个隔室中使用混合酸，用高活性改性碳材料取代昂贵的Pt正极，用阴离子交换膜取代传统的Nafion膜，以及使用零间隙流过电池的V-Ce RFB。考虑到它们的优势和缺乏可行的替代品，Zn-Ce和V-Ce rfb有望在储能技术方面取得突破，前提是克服该计划所面临的关键挑战。加拿大通过示范单位的运作和风险资本投资，在发展可再生能源方面发挥了重要作用。拟议研究的成功将有助于保持加拿大在该领域的突出地位。参与研究的四名研究生将学习一系列尖端的实验和建模技能，这将使他们能够在学术界或能源/制造业领域追求成功的职业生涯。

Given growing populations and industrialization and the shift toward renewable energy, the need for energy storage systems has never been higher. These systems store surplus energy during certain periods and discharge it on demand at other times, enabling the electrical grid to better integrate renewables with base load energy and be more robust to disturbances. Unfortunately, few storage methods are currently available and so less than 10% of the total delivered electric power worldwide comes via energy storage. Electrochemical methods are well poised to fill this gap due to their pollution-free operation, fast response, high efficiency, flexibility, portability and low maintenance. Among these methods, redox flow batteries (RFB) stand out. The electrodes are contained in separate compartments as in other batteries. Unlike conventional batteries, the reactants are dissolved in liquid electrolytes stored in external tanks and pumped continuously through their compartments where the redox reactions occur. These features give RFBs advantages over other batteries - independent control of energy and power, inherent safety, fast and reversible redox reactions, no solid-state effects, easy thermal management, no overheating, no electrolyte breakdown and long lifetimes. However, two main factors have hindered their adoption - high installed cost and durability concerns. This research program focuses on improving the performance and durability while reducing the cost of two relatively new systems - zinc-cerium and vanadium-cerium RFBs. The Ce3+/Ce4+ reaction operates at the positive electrode in both RFBs, while Zn/Zn2+ and V2+/V3+ operate at the negative electrodes. These systems are very promising since they attain higher cell voltages and potentially much higher energy and power than other RFBs. The proposed research will include i) bench-scale experiments aimed at suppressing parasitic side reactions and enhancing cell performance and durability and ii) development of a comprehensive model for each battery. Novel aspects of the research are the use of mixed acids in both compartments, replacement of expensive Pt positive electrodes with highly active modified carbon materials, replacement of conventional Nafion membranes with anion exchange membranes and use of a zero-gap flow-through cell for the V-Ce RFB. Given their advantages and the lack of viable alternatives, the Zn-Ce and V-Ce RFBs are poised for a breakthrough in energy storage technology, provided the key challenges addressed in this program are overcome. Canada has played an important role in RFB development via the operation of demonstration units and venture capital investment. Success in the proposed research will help maintain Canada's prominence in this sector. The four graduate students involved in the research will learn a broad suite of cutting-edge experimental and modeling skills that will enable them to pursue successful careers in academia or the energy/manufacturing sectors.