Applicability range of potential step chronoamperometry for determining reliable diffusion coefficients of hydrogen and lithium in host materials
Year: 2025
Type: article
Abstract: Potential step chronoamperometry is often used to study the electrochemical unloading process and to determine the diffusion coefficient D of an intercalating atom species in a host material, as it is seemingly easily applicable. The present work emphasises the importance of ensuring a diffusion-controlled unloading process during the potential step chronoamperometry measurement, if determination of the diffusion coefficient is targeted. As an example, diffusion-controlled and non-diffusion-controlled hydrogen unloading series from palladium samples and the resulting diffusion coefficients are presented, for comparison. A literature review summarising the diffusion coefficients of different intercalating species determined for several different systems by this method reveals a systematic error in the results. It turned out that insufficient diffusion control is a common issue in the application of the chronoamperometry method. Based on this finding, it is suggested to verify measurements in the diffusion-controlled regime when chronoamperometry is applied. A suitable verification technique is provided.
Source: Electrochimica Acta
Authors: Magdalena Seiler, Giorgia Guardi, Stefan Wagner, Astrid Pundt
Institution: Karlsruhe Institute of Technology
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,790
OpenAlex ID: W4416185755