Here, we report for the first time the results of systematic characterization of a low-temperature polymer electrolyte membrane direct ethanol fuel cell using DC and AC electrochemical methods. Model catalysts (carbon supported Pt nanoparticles) painted on carbon paper are used as anode and cathode. Influence of physical parameters, such as cell temperature, current density, and ethanol concentration, and anode fuel flow rate on overall cell impedance is studied. Analysis of the obtained impedance spectra in connection with DC measurements allows us to comment on cell properties and to separate different contributions to the overall cell polarization. Our results suggest that the cell impedance is dominated by anode faradaic impedance, with a small or negligible contribution from cathode faradaic impedance. The anode impedance depends strongly on current density and cell temperature, but is not significantly influenced by ethanol concentration. Presence of anode mass-transfer impedance, even when ethanol was fed to the cell in high excess, is confirmed. Based on the results, we conclude that changes in ethanol electro-oxidation mechanism might manifest themselves on the impedance spectra in the low-frequency inductive loop. Nonetheless, further studies involving equivalent circuit modelling are needed to determine the exact influence of the cell parameters on the anode kinetics.

Graphical Abstract

在这里，我们首次报告了使用直流和交流电化学方法对低温聚合物电解质膜直接乙醇燃料电池进行系统表征的结果。涂在碳纸上的模型催化剂（碳负载的Pt纳米颗粒）用作阳极和阴极。研究了诸如电池温度，电流密度，乙醇浓度以及阳极燃料流速等物理参数对电池整体阻抗的影响。结合直流测量对获得的阻抗谱进行分析，使我们能够对电池性能进行评论，并分离出对整个电池极化的不同影响。我们的结果表明，电池阻抗受阳极法拉第阻抗的支配，而阴极法拉第阻抗的贡献很小或可忽略。阳极阻抗在很大程度上取决于电流密度和电池温度，但不受乙醇浓度的明显影响。即使将乙醇过量过量地送入电解槽，也可以确认存在阳极传质阻抗。根据结果​​，我们得出结论，乙醇电氧化机制的变化可能会在低频感应环路的阻抗谱中体现出来。但是，需要进行涉及等效电路建模的进一步研究，以确定电池参数对阳极动力学的确切影响。我们得出结论，乙醇电氧化机制的变化可能会在低频感应环路的阻抗谱中体现出来。尽管如此，仍需要进行涉及等效电路建模的进一步研究，以确定电池参数对阳极动力学的确切影响。我们得出结论，乙醇电氧化机制的变化可能会在低频感应环路的阻抗谱中体现出来。尽管如此，仍需要进行涉及等效电路建模的进一步研究，以确定电池参数对阳极动力学的确切影响。

图形概要