Abstract
AC impedance spectroscopy is widely used to evaluate performance limitations in energy storage and conversion devices (e.g., batteries, supercapacitors, and fuel cells). This work shows that integrating the resistive elements in an equivalent circuit as functions of steady-state current enables one to recover overpotentials associated with different processes (e.g., ion migration, charge transfer, and diffusion) in nonlinear electrochemical power supplies. Closed form expressions for diffusion overpotentials are derived using this method for transmissive and reflective boundary conditions and three electrode symmetries (planar, cylindrical, and spherical). Discussion is also extended to macroscopically homogenous porous electrodes which are relevant for most real-world devices. Overall, the approach described herein is a powerful tool to identify rate-limiting steps and guide material/component design.
| Original language | English |
|---|---|
| Article number | 030513 |
| Journal | Journal of the Electrochemical Society |
| Volume | 171 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 31 2024 |
Funding
This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the United States (US) Department of Energy (DOE). This work is sponsored by the US DOE in the Office of Electricity (OE) through the Energy Storage Research Program and the Office of Energy Efficiency and Renewable Energy (EERE) in the Vehicle Technologies Office (VTO) through the Advanced Battery Materials Research (BMR) Program. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US DOE. The publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doepublic-access-plan). This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the United States (US) Department of Energy (DOE). This work is sponsored by the US DOE in the Office of Electricity (OE) through the Energy Storage Research Program and the Office of Energy Efficiency and Renewable Energy (EERE) in the Vehicle Technologies Office (VTO) through the Advanced Battery Materials Research (BMR) Program. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05–00OR22725 with the US DOE. The publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doepublic-access-plan ).
Keywords
- AC impedance spectroscopy
- EIS
- batteries
- energy conversion
- energy storage
- fuel cells