Design and optimization of guide flow channel for vanadium redox flow battery based on the multi-field synergy

Enhanced transmission of high efficiency and low resistance have become the key problems in facing vanadium redox flow batteries (VRFBs) flow field. This work presents an optimal concept of guide flow field based on the synergy of concentration, velocity and pressure fields. First, the structural parameter influence and multi-field synergy of VRFB with guide flow single channel (GF1C) are explored based on the math model. Second, optimal guide vane size for GF1C is identified by orthogonal optimization. Subsequently, the integrated performance of parallel and serpentine channels equipped with optimal vane are studied and validated. The results demonstrate that the height, width and number of vane are proportional to the discharge voltage and pressure loss of GF1C. Compared to blocked flow single channel, GF1C achieves higher velocity and concentration gradient synergy, albeit at the expense of reduced velocity and pressure gradient synergy. This trade-off led to an increase in the average electrolyte concentration by 1.96 %, while reducing the pressure consumption by 11.17 %. The optimized voltage result of VRFB with guide flow serpentine channel (GFSC) experiment is 2.00 % with the difference of 0.07 % from simulated result. The limiting current density of GFSC is enhanced by 7.69 % compared to that of serpentine channel.