Visualization observation of bubble behavior and performance impact analysis in efficient nickel based ordered porous electrodes
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.
国家科技期刊平台
NSTL
万方数据
