三乙醇胺对全钒液流电池正极电解液的影响

Effect of Trolamine on the Positive Electrolyte for Vanadium Redox Flow Batteries

通过热稳定性考察、紫外-可见吸收光谱、循环伏安和充放电测试,研究了三乙醇胺作为全钒液流电池正极电解液添加剂对电化学活性和5价钒电解液热稳定性的影响.实验结果表明,三乙醇胺对电解液的热稳定性有较大的提高,5价钒离子浓度在50℃下保存12h后仍有1.08mol/L,高于空白电解液的0.16mol/L.由可紫外-可见吸收光谱可知,三乙醇胺的加入没有改变钒的成键方式.同时,三乙醇胺对正极电解液的电化学活性和可逆性也有提高,有更高的峰电流和更小的峰电位差,组装的电池前30个循环平均能量效率可达80.4%,高于空白电池的1.4%.

Trolamine was used as the additive of positive electrolyte for vanadium redox flow battery.Its electrochemical performance of V（IV）/VV（V） redox couple and thermal stability of V（V） electrolyte were investigated by stabilization examination,UV-Vis absorption spectrophotometry,cyclic voltammetry and charge-discharge test.The results show that addition of trolamine can enhance thermal stability of V（V）,and the concentration of V（V） at 50 ℃ for 12 h can reach 1.08 mol/L,0.16 higher than the pristine.The UV-Vis spectra show that trolamine do not change the bonding style of vanadium ion.The addition of trolamine can enhance the electrochemical acitivity and reversibility,with larger peak current and smaller peak potential interval.The average energy efficiency of 30 cycles assembled with trolamine is 80.4%,1.4% higher than that of the pristine.