(1. 武漢科技大學(xué) 資源與環(huán)境工程學(xué)院，武漢 430081；
2. 攀鋼集團(tuán)研究院有限公司 釩鈦資源綜合利用國家重點(diǎn)實(shí)驗(yàn)室，攀枝花 617000；
3. 武漢科技大學(xué) 國家環(huán)境保護(hù)礦冶資源利用與污染控制重點(diǎn)實(shí)驗(yàn)室，武漢 430081；
4. 武漢科技大學(xué) 釩資源高效利用湖北省協(xié)同創(chuàng)新中心，武漢 430081；
5. 武漢科技大學(xué) 湖北省頁巖釩資源高效清潔利用工程技術(shù)研究中心，武漢 430081；
6. 武漢理工大學(xué) 資源與環(huán)境工程學(xué)院，武漢 430070)
摘 要: 為提高釩電池電解液的能量密度及寬溫度區(qū)間穩(wěn)定性，對(duì)基于硫酸-鹽酸混酸支持電解質(zhì)體系的電解液進(jìn)行穩(wěn)定性及電化學(xué)性能優(yōu)化。對(duì)電解液進(jìn)行釩離子及氯離子穩(wěn)定性測試，發(fā)現(xiàn)在支持電解質(zhì)配比為硫酸根濃度2.0~3.0 mol/L、氯離子濃度6.0~6.4 mol/L時(shí)，電解液釩濃度可達(dá)2.4 mol/L且四種價(jià)態(tài)的電解液均可在-20~50 ℃穩(wěn)定存在10 d以上且可以有效避免氯化氫揮發(fā)。對(duì)穩(wěn)定性優(yōu)化后的電解液進(jìn)行循環(huán)伏安及交流阻抗測試，發(fā)現(xiàn)在釩濃度為2.2 mol/L、硫酸根濃度為2.75 mol/L、氯離子濃度為5.8 mol/L時(shí)，電解液的電化學(xué)性能最佳。對(duì)濃度組成優(yōu)化的電解液進(jìn)行充放電測試，發(fā)現(xiàn)電解液可以在-20~50 ℃及40~80 mA/cm2穩(wěn)定運(yùn)行，且能量效率可達(dá)75%。
關(guān)鍵字: 釩電池；電解液；穩(wěn)定性；電化學(xué)性能
（1. College of Resource and Environment Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
2. State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization, Pangang Group Research Institute Co., Ltd., Panzhihua 617000, China;
3. State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control, Wuhan University of Science and Technology, Wuhan 430081, China;
4. Hubei Collaborative Innovation Center of High Efficient Utilization for Vanadium Resources, Wuhan University of Science and Technology, Wuhan 430081, China;
5. Hubei Provincial Engineering Technology Research Center of High Efficient Cleaning Utilization for Shale Vanadium Resource, Wuhan University of Technology, Wuhan 430081, China;
6. College of Resource and Environment Engineering, Wuhan University of Technology, Wuhan 430070, China）
Abstract:In order to improve the energy density and broad temperature adaptability of vanadium redox flow battery, the stability and electrochemical performance of electrolyte based on sulfate-chloride mixed acid electrolyte were optimized systematically. The static stability tests of vanadium ions and chloride ions show that the electrolyte of 2.4 mol/L vanadium concentration can keep stable for 10 d and the volatilization of hydrogen chloride can be effectively avoided when chloride ion concentration is 6.0-6.4 mol/L and sulfate concentration is 2.0-3.0 mol/L. The CV and EIS tests of electrolyte after stability optimization indicate that the electrolyte with 2.2 mol/L vanadium concentration, 2.75 mol/L sulfate concentration and 5.8 mol/L chloride ion concentration presents the best electrochemical performance. The charge-discharge tests of optimized electrolyte indicate that the VRFB with optimized electrolyte composition can be operated successfully at the temperature of -20－50 ℃ and the current density of 40-80 mA/cm2, and the energy efficiency can reach 75%.
Key words: vanadium redox flow battery; electrolyte; stability; electrochemical performance
