Two-Dimensional MXene Modified Electrodes for Improved Anodic Performance in Vanadium Redox Flow Batteries
Two-Dimensional MXene Modified Electrodes for Improved Anodic Performance in Vanadium Redox Flow Batteries
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DOI：
10.1149/1945-7111/ac22cd
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发表时间：
2021-09-01
影响因子：
3.9
通讯作者：
Kumbur, E. Caglan
中科院分区：
文献类型：
--
作者：
Mizrak, Ali Vala;Uzun, Simge;Kumbur, E. Caglan
本文研究了Ti3C2Tx MXene作为钒氧化还原液流电池（VRFBs）中阳极V2+/V3+反应的电催化剂材料。建立了一种简单的滴涂工艺，使用无添加剂的MXene水性分散体制备MXene涂层碳纸电极。采用循环伏安法和电化学阻抗法在三电极电池中研究了Ti3C2Tx作为阳极电催化剂的性能。此外，还进行了液流电池测试，以确定改性电极的性能。在电流密度为50 mA cm（-2）时，Ti3C2Tx负载为0.2 mg cm（-2）的电极比原始电极的能量效率提高了7%，电解质利用率提高了22%。在更高的电流密度（100 mA cm(-2)）下，能量效率和电解质利用率分别提高了17%和46%。在50%的SOC下，涂层电极能够达到220 mA cm（-2）的极限电流密度，同时保持80%以上的光伏效率，而原始电极在相同的光伏效率下只能达到160 mA cm（-2）。Ti3C2Tx纳米片的加入增强了电极动力学，增加了电化学活性表面积，改善了润湿性能。
In this work, Ti3C2Tx MXene was investigated as electrocatalyst material for the anodic V2+/V3+ reaction in vanadium redox flow batteries (VRFBs). A simple drop coating process was established using additive-free, aqueous MXene dispersions to fabricate MXene-coated carbon paper electrodes. The performance of Ti3C2Tx as an anodic electrocatalyst was studied using cyclic voltammetry and electrochemical impedance spectroscopy in a three-electrode cell. Furthermore, flow battery testing was performed to determine the performance of the modified electrodes. At a current density of 50 mA cm(-2), the electrode with Ti3C2Tx loading of 0.2 mg cm(-2) enabled a 7% higher energy efficiency and 22% higher electrolyte utilization rate than the pristine electrode. At a higher current density (100 mA cm(-2)), the energy efficiency and electrolyte utilization were increased by 17% and 46%, respectively. At 50% SOC, the coated electrode was able to reach a limiting current density of 220 mA cm(-2) while maintaining a voltaic efficiency above 80%, whereas the pristine electrode could only reach up to 160 mA cm(-2) at the same voltaic efficiency. The improved performance was mainly attributed to the enhanced electrode kinetics, increased electrochemically active surface area, and improved wetting properties due to the addition of Ti3C2Tx nanoflakes.