CHARACTERISTICS AND PERFORMANCE OF VANADIUM SOLUTION FOR ALL-VANADIUM REDOX-FLOW BATTERY

摘要

The excellent vanadium electrolyte with exactly 3.5 average vanadium valence for both positive and negative was prepared by reduction method, The current efficiency and energy efficiency were 93.9% and 80.8% at the current density 60 mA/cm2 with average output power of 5.5 kW, the higher average output power of 7.2 kW was obtained at the current density of 80 mA/cm2 with energy efficiency of 78.4%. What is more, The performance of charging and discharging of vanadium electrolyte was improved at the current density of 140 mA/cm~2, Compared to the original electrolyte, the average charging voltage of the new electrolyte reduces 35 mV, the average voltage during discharge increases 90 mV, improves the voltage efficiency of the battery. In contrast with the original electrolyte, the new electrolyte can make the charge and discharge time extended, such as prolongs discharge time from 38 minutes to 58 minutes, the performance improves by 53%. The results showed the prepared vanadium solution with good performance was achieved, indicating that the prepared vanadium solution is suitable for the VRB stack. The financial support of the research and application of solid battery with higher energy density (12QN07, XCX12068) and the preparation of vanadium solution (143010100) is greatly appreciated. The present work was partially supported by a Talent introduction fund from Hunan Agricultural University (62030112012).