Getting the Basics Right: Preparing Alkaline Electrolytes for Electrochemical Applications
Getting the Basics Right: Preparing Alkaline Electrolytes for Electrochemical Applications
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DOI：
10.1021/acsenergylett.2c02847
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发表时间：
2023-01
影响因子：
22
通讯作者：
Raúl A. Márquez;Kenta Kawashima;Yoon Jun Son;Grace Castelino;Nathaniel Miller;Lettie A. Smith;C. Chukwuneke;C. Mullins
中科院分区：
文献类型：
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作者：
Raúl A. Márquez;Kenta Kawashima;Yoon Jun Son;Grace Castelino;Nathaniel Miller;Lettie A. Smith;C. Chukwuneke;C. Mullins
电解液是每个电化学系统的重要组成部分，它决定了电极界面的基本性质和相关的性能指标。值得注意的是，碱性水溶液电解液(如KOH和NaOH)是许多电化学能量装置所必需的，包括碱性电解槽、燃料电池、超级电容器和碱性电池。碱性电解液也影响电催化反应的热力学性质和动力学，如析氧反应(OER)、析氢反应(HER)、氧还原反应(ORR)和二氧化碳还原反应(CO2RR)。1−5在过去十年中，关注这些电化学体系的研究数量有了显著的增长。然而，在这一领域工作的众多跨学科研究小组之间缺乏一致性，导致了对不同过程的误解和对绩效指标的高估，这一点以前的观点已经辩论过了。6−14最近的研究表明，碱性电解液的浓度和组成不应被认为是微不足道的，因为例如，金属杂质的存在和不准确的pH估计导致了对电化学性能的不准确描述。5、6、15−17因此，需要标准化的规程来改进和检查碱性电解液的质量，以便能够客观地评估和比较电化学能量系统。12，13在这一观点中，我们描述了制备、表征和验证用于电化学能源系统的碱性电解液质量的六种实践(图1)。通过修改以前的程序和执行特定的测量，我们提供了一个统一的方案来制备和纯化碱性电解液，标准化它们的浓度，确定它们的元素组成，提供统计指标，并检查它们的电化学性质。
The electrolyte represents a vital component of every electrochemical system that determines the fundamental properties of the electrode interface and relevant performance metrics. Remarkably, alkaline aqueous electrolytes (eg, KOH and NaOH) are essential to numerous electrochemical energy devices, including alkaline electrolyzers, fuel cells, supercapacitors, and alkaline batteries. Alkaline electrolytes also affect the thermodynamic properties and kinetics of electrocatalytic reactions, such as the oxygen evolution reaction (OER), the hydrogen evolution reaction (HER), the oxygen reduction reaction (ORR), and the CO2 reduction reaction (CO2RR). 1− 5 The number of studies focusing on these electrochemical systems has experienced significant growth in the past decade. However, the lack of consistency among numerous interdisciplinary research groups working in this field has led to the misinterpretation of different processes and the overestimation of performance metrics, which previous Viewpoints have debated. 6− 14 Recent studies have shown that alkaline electrolyte concentrations and compositions should not be considered trivial because, for example, the presence of metal impurities and imprecise pH estimations have resulted in inaccurate descriptions of the electrochemical performance. 5, 6, 15− 17 Therefore, there is a need for standardized protocols to improve and examine the quality of alkaline electrolytes so that electrochemical energy systems can be objectively evaluated and compared. 12, 13 In this Viewpoint, we describe six practices to prepare, characterize, and validate the quality of alkaline electrolytes used in electrochemical energy systems (Figure 1). By adapting previous procedures and performing specific measurements, we provide a unified protocol to prepare and purify alkaline electrolytes, standardize their concentrations, determine their elemental compositions, provide statistical metrics, and examine their electrochemical properties.