Discharge mechanism of implantable cardiac defibrillator batter analog determined by Raman and Surface Enhanced Imaging spectroscopy

Faculty Sponsor

Paul Smith


Arts and Sciences



ORCID Identifier(s)

Logan Kiesewetter(0009-0002-1747-2656), Demi Brown(0000-0002-6963-4250)

Presentation Type

Poster Presentation

Symposium Date

Summer 7-26-2023


Batteries must hit target metrics as a function of desired application. Regarding the battery in the Implantable Cardiac Defibrillator (ICD), a desired metric is predictable performance over long time scales (7-9 years). This performance is attributed to the use of a silver metal oxide electrode, which reduces into highly conductive silver metal. Here, we investigate analogous electrochemistry to the ICD battery: Zn(s) + AgxMoyOz → xAg(s)+ ZnMoyOz. We have characterized this reaction for monoclinic and triclinic Ag2Mo2O7 polymorphs by Raman spectroscopy at depths of discharge including full reduction of silver. Raman imaging maps of pellet electrodes prepared in steel mesh show a two-step heterogeneous reaction, with different reactivity of particles interfacing the electrolyte from those interfacing the back contact. Silver metal particles are spatially resolved in the electrode using surface enhanced Raman spectroscopy with methylene blue, giving an analytical enhancement factor of 103-104 at electrode hotspots. Overall, we have investigated the discharge mechanism of different cathodes towards increasing the predictability and longevity needed in ICD batteries.

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