Density differences between the renewed and resident electrolyte give rise to buoyancy forces that affect the electrolyte fluid dynamics and mixing within the tanks, potentially leading to the formation of heterogeneous regions containing unreacted electrolyte, which reduces the VRFB capacity utilization . Similarly, viscosity plays a pivotal role within the electrochemical cell, affecting ion mass transport fluxes and, consequently, the overall electrochemical performance , as well as the pressure work. In summary, accurate density and viscosity data of vanadium electrolytes is necessary to improve mathematical models and optimize VRFB design.