Multi-Harmonic Electrothermal Spectroscopy (METS), a New Technique for Spatially Resolved Electrochemical Measurements

Date Published
10/2022
Publication Type
Journal Article
Authors
DOI
10.1149/MA2022-02199mtgabs
Abstract

In this work, we introduce a new electrochemical technique, Multi-harmonic ElectroThermal Spectroscopy (METS) based on frequency dependent temperature sensing. We show that the thermal signatures generated at different harmonics when an Alternating Current (AC) is passed through an electrochemical cell can be used to extract thermodynamic (entropic), kinetic (charge transfer rate) and transport (charge and mass transport) properties associated with the electrochemical cell. From the frequency dependence of the thermal penetration depth, the spatial origin of the effect can be located within a resolution of a few microns, thereby enabling the attribution of the effect to a particular electrode. A four-point probe RTD sensor acting as a METS sensor is employed on the exterior of the current collector, which non-invasively provides spatially resolved information about the electrochemical processes in the cell. Through this work, we are able to, for the first time, determine the entropy change of a single charge transfer reaction in an electrode and spatially resolve the heat generation in a single Li-ion cell, with a length-scale resolution of a microns.

Journal
ECS Meeting Abstracts
Volume
MA2022-02
Year of Publication
2022
Issue
1
Pagination
99 - 99
URL
Short Title
Meet. Abstr.
Organizations
Research Areas
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