Abstract Water electrolysis has been one of the most studied topics in materials research in the past decade because of the global effort in exploring clean and renewable energy sources. Much effort has been devoted to developing highly active electrocatalysts for the two half reactions of water electrolysis, the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Some reported electrocatalysts are even superior to the benchmark platinum and iridium dioxide catalysts, and thus are claimed to be promising for large-scale commercial use. However, most electrochemical data in the literature are reported after iR compensation, where R is the overall resistance, including contact resistance, charge-transfer resistance, and intrinsic resistance. Unfortunately, these types of resistance cannot be avoided in real electrolyzers, which means that R still results in energy consumption if the electrocatalysts are used for industrial water electrolysis. Thus, the data with iR compensation are always misleading, and setting criteria for iR compensation in analyses of water electrolysis is urgently needed to instruct the scientific community. In this work, we test the catalytic performance of several reported HER and OER catalysts with and without iR compensation and discuss the contribution from iR compensation under small and large current densities. We also present a comparative study between two iR compensation methods (automatic and manual iR compensation). Finally, we propose some strategies to reduce the R to achieve better performance without iR compensation, which is necessary for industrial applications.

中文翻译：

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iR补偿对电解水影响的系统研究

摘要 由于全球在探索清洁和可再生能源方面的努力，水电解一直是过去十年材料研究中研究最多的课题之一。人们致力于开发用于电解水的两个半反应、析氢反应（HER）和析氧反应（OER）的高活性电催化剂。一些报道的电催化剂甚至优于基准铂和二氧化铱催化剂，因此据称有望大规模商业应用。然而，文献中的大多数电化学数据都是在 iR 补偿后报道的，其中 R 是总电阻，包括接触电阻、电荷转移电阻和固有电阻。不幸的是，在真正的电解槽中无法避免这些类型的电阻，这意味着如果电催化剂用于工业水电解，R 仍然会导致能源消耗。因此，具有 iR 补偿的数据总是具有误导性，迫切需要在水电解分析中设定 iR 补偿的标准以指导科学界。在这项工作中，我们测试了几种已报道的具有和不具有 iR 补偿的 HER 和 OER 催化剂的催化性能，并讨论了在小电流密度和大电流密度下 iR 补偿的贡献。我们还介绍了两种 iR 补偿方法（自动和手动 iR 补偿）之间的比较研究。最后，我们提出了一些降低 R 的策略，以在没有 iR 补偿的情况下实现更好的性能，这是工业应用所必需的。