Empirical modelling of current density distribution as a function of potential, flow velocity, and electrolyte concentration in alkaline water electrolysis

This article gives a critical review of data obtained from previous studies involving the current distribution on the cathode during alkaline water electrolysis. From previous experimental data, empirical models, relating current density distribution on the cathode to potential, electrolyte flow velocity and electrolyte concentration, have been proposed; this approach contributes significantly to understanding the cathode behaviour during alkaline water electrolysis, where the screening caused by gas void distribution along the cathode controls the current distribution locally and globally. For each operating condition, a fourth-degree polynomial model has been observed, fitting experimental data previously. Empirical correlations have been developed over potential, concentration and electrolyte flow velocity ranges. These correlations have been compared with previous data and show good accuracy over the studied ranges.

本文对既往研究中获取的碱性水电解（alkaline water electrolysis）过程阴极（cathode）表面电流分布相关数据进行了批判性综述。基于既往实验数据，已有研究提出了将阴极电流密度（current density）分布与电位、电解质（electrolyte）流速及电解质浓度相关联的经验模型（empirical model）；该方法为理解碱性水电解过程中的阴极行为做出了重要贡献——在此过程中，沿阴极分布的气体空穴所引发的屏蔽效应，从局部与全局层面共同调控着电流分布。针对每种运行工况，既往研究均已观测到可适配实验数据的四次多项式模型（fourth-degree polynomial model）。研究人员已针对电位、浓度及电解质流速的各取值区间，构建了相应的经验关联式。将这些关联式与既往数据对比后可见，其在本研究覆盖的区间内展现出良好的预测精度。