基于电化学改性石墨电极构建钒/钛液流电池

摘要

在2.0 mol/L HClO4溶液中通过恒电流阶跃方法制备了电化学改性石墨电极(MGE).发现其在硫酸溶液中对Ⅴ(Ⅳ)/Ⅴ(Ⅴ)和Ti(Ⅲ)/-ri(Ⅳ)氧化还原反应具有良好的催化可逆性,并提出了受电位影晌的电极表面含氧官能团电对与金属离子电对间的氧化还原协同作用机理.将Ⅴ(Ⅳ)N(Ⅴ)和Ti(Ⅲ)/Ti(Ⅳ)分别作为正、负极活性物质构建成氧化还原液流电池并评价其充放电性能.在10 mA/cm2下恒流充放电,相应的电压效率为94.2％,能量效率达到91％,展示了基于MGE构建的钒/钛液流电池潜在的应用价值.%A graphite electrode was modified by galvanostatic step method in 2.0 mol/L HClO4 solution.The electrochemically modified graphite electrode (MGE) shows high electrocatalytic activity and good reversible characteristics for Ⅴ(Ⅳ)N(Ⅴ) and Ti(Ⅲ)/Ti(Ⅳ) in H2SO4solution.A synergetic mechanism between the radox reaction of surface oxygen-containing groups dependent on potential with that of Ⅴ(Ⅳ)N(Ⅴ) and Ti(Ⅲ)/Ti(Ⅳ) was proposed.Then a V/Ti redox flow battery (RFB) using Ⅴ(Ⅳ)N(Ⅴ) as positive and Ti(Ⅲ)/Ti(Ⅳ) as negative active materials was set up and its charge-discharge performance was tested.At the current density of 10 mA/cm2,the voltage efficiency is 94.2％,and the energy efficiency reaches 91％,therefore,it shows potential application value.