VFB 健康管理状态的经济学.pdf

1、ENERGY STORAGE-Long Duration Energy Storage Solution for a Sustainable Future-The economics of state-of-health management for the VFBAdam H.Whitehead,Martin Harrer,Jie Sun,Peter Pokorny2 2State-of-health(SOH)is a term that is used in many ways.In the following it relates to the average oxidation sta

2、te of the vanadium electrolytes.Perfectly healthy=3.50 average oxidation statethis is typically the starting state for a new batteryCompletely unhealthy=4.00 average oxidation stateThe battery has no discharge capacityWe consider rebalance is necessary at 3.60 average oxidation stateTHE ECONOMICS OF

3、 SOH MANAGEMENT FOR THE VFB3 3Electrolyte rebalanceElectrolyte oxidation leads to capacity loss,and if not corrected,can lead to stack damage(overcharging of the positive electrodes)THE ECONOMICS OF SOH MANAGEMENT FOR THE VFB4 40510152025020406080100jH2A/cmChemical SOC%H2evolution rates are strongly

4、 dependent on the state-of-charge range over which the electrolyte is operatedTherefore,the use case use case affects the rate of oxidationAdditionally,the maximum allowed chemical SOC and stack voltage also have an impact.THE ECONOMICS OF SOH MANAGEMENT FOR THE VFB5 5Impurities can be grouped as:1)

5、increase hydrogen evolution rates(e.g.Cu,Ir)2)block the cell be forming precipitates or deposits(e.g.Si,Bi)3)reduce the proton concentration electrolyte/membrane conductivity(e.g.Na,K)Of these the(2)must be within specification,(3)can generally be tolerated,but group(1)is of interest here.Electrocat

6、alytic element concentration can be reduced by a cleaning process,leading to higher purity electrolyteTHE ECONOMICS OF SOH MANAGEMENT FOR THE VFB6 6THE ECONOMICS OF SOH MANAGEMENT FOR THE VFBLaboratory investigations were carried out by stepwise addition of impurity elements,from a stock solution.H2