Effect Of Injector-Assisted Flow Field On The Performance Of Vanadium Redox Flow Battery Based On Ionic Mass Transport Enhancement

Vanadium redox flow battery(VRFB)is considered as a promising larger scale energy storage system for its independently tunable power and capacity and avoiding of cross contamination between positive and negative.Ionic mass transport in electrolyte is always a key factor which can affect the battery performance,and with the cell scale up,the unreasonable ionic mass transport will result in serious polarization.Optimizing mass transport and improving polarization becomes the top priority,reasonable flow channel can change the mass transport style by change the flow mode,which is the first choice to solve polarization problem.At present,most researches to mass transport mainly focus on the uneven spatial distribution of electrolyte and the concentration between surface of electrode and bulk solution,many kinds of flow channel have been designed to solve those problem.However,there is also a concentration between inlet and outlet of electrolyte,we aim to solve this issue.Operating parameters also play an important role in guiding the operation of VRFB,reasonable working conditions can give full play to the potential of VRFB and reduce operating costs.So far,most researches to operating parameters mainly focus on the influence of temperature on the call performance,however,there are few studies on flow rate and current density.The electrolyte flow rate directly affects the mass transport style on the surface of electrode,current density can change the reaction rate to affect mass transport style indirectly.This paper bases on the flow rate range of 2-50mL/min and current density range of 20-80mA/cm2.In this paper,we proposed a novel design of injector-assisted flow channel which we called iVRFB.Compared to the conventional VRFB,which do not have flow fields on the electrodes and the electrolyte is directly supplied into the electrode along the diagonal direction,this design efficiently eliminates the stagnation region and hence has obvious advantages over the conventional VRFB due to substantial enhancement of ionic mass transfer.While exploring the influence of injector-assisted flow channel,we propose the reasonable operating parameters for VRFB and iVRFB by analyzing the cell performance on different flow rates and current densities.At last,we optimize the injector-assisted flow channel,and explore the influence of the length of the channel on the cell battery.