[Objective] Vanadium flow batteries(VFBs) are promising candidates for large-scale and long-duration energy storage. However

their practical application is still constrained by high capital cost and low energy density. Flow field design plays a critical role in enhancing mass transport within the electrodes and thereby improving overall battery performance. This study aims to clarify the influence of different flow field configurations on key parameters in VFBs. [Methods] A three-dimensional multi-physics coupling numerical model was established

incorporating fluid flow

mass transport

charge conservation in both solid and liquid phases

electrochemical reaction kinetics

and heat generation. The model was applied to a laboratory-scale vanadium flow battery with a rectangular electrode area of 4 cm ×7 cm. Based on the validated framework

a systematic optimization of interdigitated flow fields was conducted from global layout to local structural parameters

including main channel orientation

branch channel arrangement

branch channel width and rib width. Subsequently

the study conducted a parametric sensitivity analysis on the optimized flow channel

focusing on electrolyte flow rate

initial state of charge(SOC)

and electrode compression ratio. This analysis quantitatively evaluated key performance indicators including velocity

concentration

polarization

terminal voltage

and power-based energy efficiency

aiming to investigate the interrelationships among these physical parameters. [Results] The simulation results demonstrate that aligning the main channels parallel to the electrode length direction significantly enhances under-rib convection by increasing the number of ribs and shortening branch channel length

thereby improving electrolyte penetration into deep electrode regions. A single alternating interdigitated arrangement of inlet and outlet branch channels effectively suppresses preferential flow toward the outlet side and reduces flow dead zones near the electrode edges. The optimal flow field configuration is achieved when both the branch channel width and rib width are 3 mm

under which concentration polarization is minimized to 0.26 mV

representing the lowest value among the 12 investigated flow-field structural parameter combinations. Meanwhile

the maximum temperature decreases to approximately 26.45 ℃

and the power-based energy efficiency reaches 89.58%. [Conclusion] Parametric analyses reveal that an electrolyte flow rate of 7.5 mL/min provides an optimal balance between enhanced mass transport and increased pumping losses. When coordinated with appropriate flow rate under a constant total cell thickness

higher compression ratios lead to increased terminal voltage and efficiency

with the maximum temperature rise remaining below 3 ℃. This research provides guidance for the flow field design of high-performance vanadium flow batteries.