Investigating thickness dependency of artificial CEI Al-based thin film in silver vanadium oxide cathode

High-power implantable medical devices today use a lithium primary battery with silver vanadium oxide (SVO) cathode—Li/SVO battery, which is prone to interfacial degradation through dissolution of vanadium ions hampering structural stability and impeding electrochemical performance resulting in surgical replacement of the device. A promising method for controlling interface-induced failure is to engineer an artificial cathode electrolyte interphase (ART-CEI) as a protective layer. Therefore, we explore the effects of ART-CEI layers on SVO cathodes for use in cardiac implantable electronic devices (CIEDs). Atomic layer deposition (ALD) was employed to deposit thin films of aluminum oxide (Al₂O₃) and lithium aluminum oxide (LiAlO₂) on SVO, creating a range of thicknesses for the ART-CEI layer. Through short- and long-term galvanostatic discharge measurements, we found that the introduction of the ART-CEI layer led to improvements in capacity and delaying V⁴⁺ reduction extending cell longevity, compared to pristine SVO. The results suggest an optimal coating thickness needs to be designed and engineered, as the electrochemical performance varies depending on the discharge rate. This study contributes to the growing body of research on enhancing lithium technology for high-power medical applications, paving the way for future refinements in ALD techniques for creating optimized and tailored artificial CEI coatings.