发表机构
Institute of Mechanical Engineering, EPFL（EPFL机械工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过模型和实验证明，毛细管供给水电解的无气泡运行极限由隔膜孔径决定，减小孔径可显著提升极限并降低电压，表明该极限是可设计的。
AI 中文摘要
在工业相关速率下，气泡对水电解造成巨大损失。毛细管供给电解槽通过将电解液吸入电极并从背面排出气体来大幅缓解这一问题，但仅在低于阈值电流密度时有效。我们表明，隔膜孔径通过两种相反效应决定该阈值：较小的孔径提高了成核所需的过饱和度，但降低了电解液补充的渗透性。一个耦合的电化学-传输模型，以单次测量的起始点为锚定，量化了0.1-8微米孔径范围内的两种机制。实验上，将孔径从8微米减小至1.2微米，将气泡起始极限从0.18 A cm⁻²提高到1.73 A cm⁻²，并在1 A cm⁻²下将电池电压降低0.11 V，主要通过抑制气泡引起的过电位实现。在0.45微米及以下，补充极限占主导，电池在气泡形成前即干燥。我们的研究确立了无气泡运行极限是可设计的，而非纯粹经验性的。
英文摘要
Gas bubbles impose large penalties in water electrolysis at industrially relevant rates. Capillary-fed electrolyzers greatly mitigate them by wicking electrolyte to electrodes and venting gas from the backside, but only below a threshold current density. We show that the separator pore size sets this threshold through two opposing effects: smaller pores raise the supersaturation required for nucleation but reduce the permeability for electrolyte replenishment. A coupled electrochemical-transport model, anchored to a single measured onset, quantifies both mechanisms across 0.1-8 $μ$m pores. Experimentally, reducing pore size from 8 to 1.2 $μ$m raises the bubble onset limit from 0.18 to 1.73 A cm$^{-2}$ and lowers cell voltage by 0.11 V at 1 A cm$^{-2}$, primarily by suppressing bubble-induced overpotential. At 0.45 $μ$m and below, the replenishment limit takes over and the cells dry out before bubbles form. Our findings establish the bubble-free operation limit as designable rather than purely empirical.
