全钒液流电池碳毡电极的热处理活化研究  

Study on thermal treatment activation of carbon felt electrode for all-vanadium flow batteries

作　　者：王泓 张开悦 WANG Hong;ZHANG Kaiyue(School of Materials Science and Engineering,Shenyang Ligong University,Shenyang 110159,Liaoning,China)

机构地区：[1]沈阳理工大学材料科学与工程学院,辽宁沈阳110159

出　　处：《储能科学与技术》2025年第2期488-496,共9页Energy Storage Science and Technology

基　　金：国家自然科学基金(22309121);辽宁省自然科学基金(2024-BS-118);辽宁省属本科高校基本科研业务费专项(LJ212410144035)。

摘　　要：钒电池是发展低碳电力系统急需的长时储能技术,开发高功率电堆是推进钒电池规模应用的重要途径。电极,作为钒电池功率单元的关键材料,是实现高功率电池技术的核心。为了改善现有碳毡电极的电化学性能,本工作设计了两种热处理活化策略,即低温长时处理和高温短时处理。在空气气氛下,通过调节处理温度和时间对原始碳毡进行活化改性。利用扫描电镜、X射线衍射、X射线光电子能谱、接触角测试、循环伏安、交流阻抗及单电池充放电测试研究了活化电极的物理化学及电化学性能。结果表明:低温长时处理能够可控地增加碳毡纤维粗糙度,且对石墨结构影响较小,保证碳毡的力学性能。经450℃热处理6 h后的活化碳毡对VO^(2+)/VO_(2)^(+)和V^(2+)/V^(3+)反应表现出最佳的电化学活性,BET比表面积增加至1.75 m^(2)/g,表面含氧官能团含量增加至10.38%(原子百分比),引入的极性基团极大改善了电极的亲液性。将活化后的碳毡组装到单电池中,电池在300 mA/cm^(2)电流密度下可实现77.8%能量效率,远高于原始碳毡。本工作为现有商用碳毡电极的活化改性提供了实用化指导思路,对高功率钒电池开发具有重要实际意义。Vanadium flow battery(VFB)is imperative long-term energy storage technology for the development of low-carbon power systems.Developing high-power stacks is an important way to promote the scale application of VFB.Electrode,as a crucial material in a VFB power unit,is the key to realize high-power battery technology.To enhance the electrochemical performance of commercial carbon felt electrodes,two thermal treatment activation strategies are proposed in this work:low-temperature long-time treatment and high-temperature short-time treatment.Specifically,in the air atmosphere,pristine carbon felts are activated by adjusting the processing temperature and time.Physical,chemical,and electrochemical properties of activated electrodes are characterized using scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,contact angle measurement,cyclic voltammetry,electrochemical impedance spectroscopy and single-cell charge-discharge tests.Results indicate that low-temperature long-time treatment controllably increases carbon felt fiber roughness,and preserves mechanical stability while introducing oxygen functional groups with minimal impact on the graphite crystal structure.After thermal treatment at 450℃for 6 h,the activated carbon felt exhibits the best electrochemical activity for VO^(2+)/VO_(2)^(+) and V^(2+)/V^(3+) reactions.The BET surface area increases to 1.75 m^(2)/g,and the content of oxygen functional groups on the surface increases to 10.38%(atomic percentage).Optimized activated carbon felt electrodes exhibit 77.8%energy efficiency at 300 mA/cm^(2),surpassing pristine carbon felt.This study offers practical guidance for activating commercial carbon felt electrodes.It is of great practical significance for the development of high power VFB.

关 键 词：全钒液流电池 电极 碳毡 热处理 活化 

分 类 号：TM911[电气工程—电力电子与电力传动]