Navigating iR Compensation: Practical Considerations for Accurate Study of Oxygen Evolution Catalytic Electrodes
Year: 2023
Type: editorial
Abstract: InformationI n a three-electrode electrochemical system, uncompen- sated resistance (R u ) between the working and reference electrodes results in an electrostatic potential drop called iR potential drop, where i is a measured current.1,2 This iR potential drop skews the applied potential, meaning the potential set by the electrochemist is not the true applied potential.Thus, iR compensation needs to be performed to study the potential-dependent electrochemical behavior precisely.There are three commonly used methods for iR compensation: (1) positive feedback (PF), (2) current interrupt (CI), and (3) post-iR compensation after electrochemical analysis (Post).3,4 For the R u measurement, alternating current (AC) technique-based electrochemical impedance spectroscopy (EIS) analysis, either automatically by software or manually, is used for PF and Post compensation methods.On the other hand, direct current (DC) techniquebased current interruption is used for the CI compensation method (see Supporting Note 1 for details about the R u measurement and iR compensation methods).3 However, despite the common use of the aforementioned compensation methods, there is a potential risk of performing inaccurate iR compensation that may lead to misleading results.This risk can arise from a lack of understanding of the underlying concepts and experimental and analytical methodologies involved in these compensation methods.Numerous studies and reviews have been conducted to address the concerns related to iR compensation.These studies focus on topics such as the identity of R u and i, 5,6 measurement and selection of R u , 2,6 minimization of R u , 2 overcompensation of iR potential drop, 7 ambiguity about the degree of iR compensation, 8 inconsistent results from different iR compensation methods, 4 and data processing for post iR compensation.7 Nevertheless, the practical application of iR compensation, in terms of accurate measurement and interpretation of R u , selection of an appropriate iR compensation method, and understanding their effects on electrochemical analyses, as depicted in Figure 1, remains a challenging task.This is primarily due to the complexity of various electrochemical systems.Depending on factors such as the specific electrochemical reaction (e.g., water electrolysis and CO 2 electrolysis), electrode properties (e.g., composition and structure), and experimental conditions for electrochemical testing (e.g., electrolyte, cell design, applied potential, and operating
Source: ACS Energy Letters
Institutions: The University of Texas at Austin, Texas Materials Institute
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4386951960