Performance and Techno-Economic Investigation of Organic Redox Flow Batteries: An Experimental and Modeling Study

Abstract

This thesis investigates the chemical and techno-economic efficacy of Organic Redox Flow Batteries (ORFBs). Research has identified the class of redox flow batteries as a promising solution for storing renewable energy from solar and wind sources, and for grid-level applications. In particular, ORFBs stand out due to their sustainable, cost-effective, and metal-free nature. The study focuses on two distinct ORFB systems, namely the MV/Tempol system and the AQDS/BQDS system, and compares their performance with the well-established Vanadium redox flow battery system. Different electrochemical techniques such as galvanostatic cycling, impedance spectroscopy, etc. were employed to gauge the performance parameters used in the assessment of the performance of the three battery systems. Given the close relationship between the topic and industrial economics, a comprehensive techno-economic study was also conducted using multiple cost comparison methods, contrasting ORFBs with the already commercialized Vanadium system. For this purpose, a pre-existing techno-economic model was transformed into a desktop application, called FLOTE, which is capable of generating cost calculations and distributions. Cost analyses were then performed using the cost outputs from FLOTE. The study emphasizes the importance of comparing large-scale energy storage systems based not only on performance but also on other equally vital parameters such as techno-economics and sustainability. FLOTE was made available as a tool for studying the techno-economics of any flow battery system. However, its full utilization also enables the generation of several battery optimization strategies, that could potentially reduce the costs of ORFBs. The experimental results revealed many primary challenges within the ORFB chemistry, to which several methods and techniques were suggested that could improve performance. Overall, the study bridges the gap between the laboratory chemistry of ORFBs and their industrial implementation. It contributes to the development of sustainable, cost-effective, and efficient energy storage systems, which can play a critical role in enabling a more renewable and resilient energy future.