Study On Solution Chemistry Of Electrolyte On Non-Vanadium Redox Flow Battery

As a kind of important large-scale energy storage equipment, flow battery willplay an increasing important role in grid connected power transmission for new powerenergy generation, and will become one of the best alternate power in those remoteareas. Due to the restriction of ion-exchange membrane, traditional flow battery islimited used in large-scale commercial operation. However, non-vanadium redox flowbattery is out of dependence on ion-exchange membrane so it can not occurphenomenon of ions cross-contamination. Hence, non-vanadium redox flow batteryhas provided a new method and broaden range of applications for the development offlow battery. Concentrated study has been focused on the research and development forflow battery.Single flow acid Cu-PbO₂battery and single flow acid Cd-PbO₂battery are twokinds of important non-vanadium acid redox flow battery. The principle of the twobatteries is same. There is only one electrolyte in each battery. The electrolyte is notonly reaction media but also energy carrier, so the effect of electrolyte on theperformance of the battery is very obvious. In this work, the effect of electrolytecategory and concentration on electrochemical performance was tested by cyclicvoltammetry （CV）, linear sweep voltammetry （LSV） and electrochemical impedancespectroscopy（EIS）. Suitable scope of the electrolyte has been obtained. The effect of theelectrolyte on battery is investigated by charging and discharging test of assemblybattery. The electrode test methods are charge and discharge, X-Ray diffraction（XRD）,scanning electron microscope （SEM）. The optimization of the electrolyte has beenobtained though comprehensive analysis of electrode and battery.It is concluded that: Firstly, the effect of various components in electrolyte onelectrode and battery is very obvious. Secondly, the optimization of the electrolyte is0.6mol/L CuSO4+1.45mol/L H2SO4in single flow acid Cu-PbO₂battery. Thirdly, the optimization of the electrolyte is0.5mol/L CdSO4+1.0mol/L H2SO4in singleflow acid Cd-PbO₂battery. Finally, the coulombic efficiency is55%in single flowacid Cu-PbO₂battery and71%in single flow acid Cd-PbO₂battery after charging anddischarging cycles under stability of the battery.