This study presents a phenomenological estimation framework for a membraneless alkaline water electrolyzer (MAWE), developed primarily from experimentally measured current signals and end-of-test mass-loss data. Thirteen KOH concentrations (5–35 g in 1 L deionized water) were investigated under a constant 12 V DC supply for 7200 s. The time-varying current was continuously recorded throughout each experiment, while the total gas production was determined from the net mass loss measured at the end of the electrolysis process. A time-resolved hydrogen-production representation was subsequently reconstructed from the measured current signal using Faraday’s law and constrained to be stoichiometrically consistent with the experimentally observed total mass loss. The term “charge-consistent” used throughout this study does not imply a new electrochemical principle, but rather refers to maintaining physical consistency between the experimentally measured current signal, Faraday-based charge transfer, and the experimentally observed end-of-test mass loss within the proposed phenomenological framework. Experimental results indicate that both the current response and the cumulative gas production exhibit a strong and distinctly nonlinear dependence on the KOH concentration. Two phenomenological modeling approaches were examined. The first is a static polynomial formulation describing the nonlinear relationship between the measured current signal and the reconstructed production rate. The second is a semi-empirical grey-box formulation in which the Faraday-based theoretical production term is corrected using an experimentally identified efficiency coefficient. Model performance was assessed using train/test data partitioning, residual analysis, autocorrelation functions, and Ljung–Box tests, demonstrating a high degree of internal charge consistency and macroscopic agreement with the reconstructed experimental representation. The proposed framework provides a reduced-order and experimentally accessible approach for representing reconstructed production behavior in MAWE systems without resorting to detailed multi-physics modeling or EIS-based characterization and offers a physically consistent baseline for comparison with more complex data-driven or control-oriented modeling strategies.

Proton Değişim Membranlı (PEM) elektrolizörlerde, suyun hidrojen ve oksijene ayrışması, uygulanan Doğru Akım (DA) kadar sistemin nem yönetimine de bağlıdır. Nem, proton iletkenliğini artırarak elektrokimyasal süreci desteklerken, aşırı birikimi (flooding) gaz difüzyonunu engelleyerek sistem performansını ciddi şekilde düşürmektedir. Bu çalışmada, nemin PEM elektrolizörlerdeki etkileri detaylı şekilde analiz edilmiş, flooding mekanizmaları incelenmiş ve Gaz Difüzyon Katmanı (GDL) tasarımının bu sorunun hafifletilmesine yönelik katkıları değerlendirilmiştir. Optimum nem seviyelerinde maksimum elektrolitik verim elde edilirken, yetersiz nem koşulları proton iletkenliğini sınırlandırmakta, aşırı su birikimi ise elektrot yüzeylerini tıkayarak gaz çıkışını engellemektedir. Bu bağlamda, GDL'nin hidrofobik kaplamalar, gradyan gözenek yapıları, mikrokanallar ve hibrit malzeme kombinasyonları ile optimize edilmesi, etkin su yönetimi sağlayarak flooding riskini minimize etmektedir.