高效镍基有序多孔电极气泡行为可视化观测及性能影响  

Visualization observation of bubble behavior and performance impact analysis in efficient nickel based ordered porous electrodes

作　　者：胡志豪 张皓景 周叶 吴睿 HU Zhihao;ZHANG Haojing;ZHOU Ye;WU Rui(China-UK Low Carbon College,Shanghai Jiao Tong University,Shanghai 201306,China;School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学中英国际低碳学院,上海201306 [2]上海交通大学机械与动力工程学院,上海200240

出　　处：《化工进展》2024年第2期680-687,共8页Chemical Industry and Engineering Progress

基　　金：DFG-NSFC中德合作交流项目(M-0545);上海市启明星培育(扬帆专项)项目(22YF1419500)。

摘　　要：碱性电解水(AWE)制氢是目前应用最广、商业化规模最大的电解水制氢技术,在碱性电解水系统中,突破析氧反应(OER)的性能瓶颈对提升电解水性能有着巨大意义。析气反应中气泡的行为会造成电极电阻的增加、反应时运输阻力的增加及电极电化学活性表面积(ECSA)的减少等影响,特别是在高电流密度下气泡对于析气反应的传质传荷阻力增加十分巨大。在碱性电解水系统中对于电极内部气泡行为的观测研究目前暂有空白。本工作通过电火花放电技术(EDM)制作出了镍基有序多孔电极,实验观测到该结构电极对析气反应中的气泡合并、对通道表面的黏附及排除过程中的禁锢有所抑制。同时,该结构电极在碱性电解水析氧反应中表现出了优异的性能,其在相同高电位下的OER几何电流密度是普通工业用泡沫镍电极的三倍之多,ECSA归一化电流密度能达到11倍之多。本文阐释了在碱性电解水系统中电极内部气泡行为,以及镍基有序孔电极是如何影响电解水性能,为工业上电解水电极设计提供了一个高效可行的方案。Alkaline water electrolysis(AWE)is currently the most widely applied and commercially scaled technology for water electrolysis.In AWE systems,breaking through the performance limitations of oxygen evolution reaction(OER)holds great significance for enhancing electrolysis performance.The behavior of bubbles in the gas evolution reaction causes an increase in electrode resistance,transport resistance during the reaction,and a decrease in the electrochemical active surface area(ECSA)of the electrode.This effect is particularly significant at high current densities,where bubbles impose substantial mass and charge transport resistance on the gas evolution reaction.Currently,there is a lack of research on the observation of internal bubble behavior in AWE systems.This study employed the Electric Discharge Machining(EDM)technique to fabricate nickel-based electrodes with order square corn holes(OSCH-Ni).Experimental observations revealed that OSCH-Ni electrodes inhibit bubble coalescence during the gas evolution reaction and restrict bubble adhesion and expulsion processes on the channel surface.Furthermore,OSCH-Ni electrodes exhibited excellent performance in the oxygen evolution reaction in alkaline water electrolysis.At the same high potential,the geometric current density of OSCH-Ni for OER was more than three times that of a typical industrial foam nickel electrode,and the normalized current density of ECSA exceeded 11 times.This work elucidates the behavior of internal bubbles in alkaline water electrolysis systems and how nickel-based ordered porous electrodes affect water electrolysis performance.It also provides an efficient and feasible solution for the design of industrial water electrolysis electrodes.

关 键 词：电解 多孔介质 析气反应 可视化实验 两相流 

分 类 号：TH3[机械工程—机械制造及自动化]