Semi-Solid Flow Batteries: Fundamentals, Recent Advances, and Future Perspectives

Renewable energy intermittency drives the need for large-scale energy storage, and semi-solid flow batteries (SSFBs) are promising candidates due to their high energy density derived from semi-solid slurry electrolytes. However, gaps persist in the fundamental understanding of slurry electrolytes, and dedicated reviews are scarce. This review summarizes SSFB research across key aspects: (i) slurry electrolyte components (active materials, conductive additives, surfactants, electrolytes) and their roles; (ii) slurry physicochemical properties (stability, rheology, conductivity) and regulatory mechanisms; (iii) operating modes, electrochemical performance, and core technical challenges. Recent advances in electrode materials development, transport kinetics optimization, and innovative reactor designs are emphasized. Future directions focus on materials modification, slurry property precise regulation, reactor scaling, and standardized characterization methods. This work consolidates the multi-disciplinary research system of SSFBs (integrating electrochemistry, materials science, colloidal science, and fluid mechanics) and provides insights to accelerate SSFB technology maturation and industrial application.