Enhancing Redox Flow Battery Performance Across Wide Temperature Ranges: Mechanisms, Challenges, and Optimization Strategies for Electrodes, Membranes, and Electrolytes

Abstract

Redox flow batteries (RFBs) are increasingly recognized as ideal candidates for largescale energy storage due to their safety, long-duration storage capabilities, extended cycle life, and flexibility in site selection. However, their practical applications are significantly hindered by poor adaptability to wide temperature ranges. Elevated temperatures (>45 ℃) can cause precipitation of active materials, membrane degradation, and increased side reactions, while low temperatures (<10 ℃) lead to higher electrolyte viscosity, crystal precipitation, and compromised mass transfer.Given that ambient conditions and operational temperatures often fall outside the optimal range (10-45 ℃), addressing these challenges is critical. This paper examines the failure mechanisms of RFBs under extreme temperatures and reviews strategies to enhance their adaptability, focusing on three key components: electrodes, membranes, and electrolytes. For electrodes, strategies include optimizing macroscopic parameters, increasing active surface area, and introducing catalytic sites. Membrane optimization involves improving physical structures, designing composite systems, and regulating interfacial chemistry. Electrolyte optimization encompasses four approaches: designing molecular structures and regulating concentration ratios for active materials; remodeling physicochemical properties and adjusting solute-solvent interactions for solvents; managing chemical microenvironments and constructing multi-component systems for supporting electrolytes; and modifying molecular complexation and solvation structures with additives. The review also analyzes current challenges and proposes future directions, including the development of novel in-situ characterization techniques and the AI-driven innovation of battery components. This work aims to provide a theoretical framework for optimizing RFB performance and facilitating their large-scale deployment in challenging environments.