PFI-TT: Development of Fire-Safe and Low-Cost Flow Batteries for the Storage of Residential Solar Energy

创新伙伴关系-技术转化（PFI-TT）项目的更广泛影响/商业潜力来自于提高数百万家庭对停电的抵御能力。近年来，越来越多的极端天气事件导致自然灾害激增，如野火和飓风，其中许多破坏了电网，使成千上万的家庭几天或几周没有电。解决国家电网脆弱性的一个战略是提高住宅和其他住宅综合体的能源自给自足，例如，将屋顶太阳能电池阵列与长期储能系统相结合。锂离子电池通常是储存太阳能的首选设备。不幸的是，火灾安全风险和高昂的生产成本限制了锂离子电池在居民区的应用。目前，只有大约20%的家庭太阳能用户安装了储能设备。该PFI-TT项目旨在开发可广泛用于居民区的防火低成本铁铬氧化还原液流电池。在这个项目中开发的电池可能比锂离子电池便宜约30%，并且电池内部不包含自燃火灾危险。拟议的项目有两个研究和发展目标。第一个目标是合成和测试新型全氟膦酸-锆聚合物膜，这种膜可以传输质子，但减少不必要的金属电解质交叉。这种膜可能有助于解决阻碍新型铁铬氧化还原液流电池发展和商业化的电解质交叉挑战。氟聚合物的制造将通过在实验室合成的新型全氟丁烯单体与六氟丙烯共聚来进行。第二个目标是设计、建造和评估一个7千瓦的小型铁铬氧化还原液流电池组，该电池组可以出售给住宅太阳能业主，以支持现有的屋顶太阳能电池板。电池的设计参数，如单个电池的尺寸，衬垫和流动通道将被系统地研究，以优化电池堆的性能。如果这个PFI-TT项目成功，这项研究可能会导致用于住宅储能的防火和低成本铁铬电池的商业化，并发现新的质子导电含氟聚合物，可广泛用于燃料电池、电解槽、氯碱电池和其他类型的液流电池。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。

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project is derived from improving the resilience of millions of homes against power outages. In recent years, an increasing number of extreme weather events has caused a surge in natural disasters such as wildfires and hurricanes, many of which knocked the power grid down—leaving thousands of families without electricity for days or weeks. A strategy to address the vulnerability of the national grid is to improve the energy self-sufficiency of houses and other residential complexes, for example, by combining roof-top solar arrays with long-duration energy storage systems. Lithium-ion batteries are usually the devices of choice for storing solar energy. Unfortunately, fire safety risks and high production costs have limited the adoption of lithium-ion batteries in residential areas. At present, only about 20% of home-solar owners have installed energy-storage devices. This PFI-TT project aims to develop fire-safe and low-cost iron-chromium redox flow batteries that can be widely used in residential areas. The batteries developed in this project may be about ~30% cheaper than lithium-ion batteries and do not contain self-igniting fire hazards inside the cells. The proposed project has two research and development goals. The first goal is to synthesize and test the novel perfluorophosphonic acid-zirconium polymer membranes that transport protons but reduce unwanted metal electrolyte crossovers. Such membranes may help address the electrolyte crossover challenge that has prevented the development and commercialization of novel iron-chromium redox flow batteries. The fabrication of fluoropolymers will be carried out by copolymerizing hexafluoropropylene with a novel perfluorobutene monomer that is synthesized in the laboratory. The second goal is the design, construction, and evaluation of a small iron-chromium redox flow battery stack at 7 kW, which can be sold to a residential solar owner to support existing rooftop solar panels. The cell design parameters such as the dimension of single cells, gaskets, and flow channels will be systematically investigated to optimize the performance of the battery stack. If this PFI-TT project is successful, this research may lead to the commercialization of fire-safe and low-cost iron-chromium batteries for residential energy storage and discovery of new proton-conductive fluoropolymers that can be widely used in fuel cells, electrolyzers, chlor-alkali cells, and other types of flow batteries.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.