Physics-based Modeling of Pulse and Relaxation of High-rate Li/CF$_{x}$-SVO batteries in Implantable Medical Devices

• DOI: 10.48550/arxiv.2402.03677
• Publication Date: 2024-02-05
• Authors: Qiaohao Liang; Giacomo Galuppini; Partha M. Gomadam; Prabhakar A. Tami...; Jeffrey A. Lemmerman; Michael J. M. Mazack; Melani G. Sullivan; Richard D. Braatz; Martin Z. Bazant
• Keywords: Pulse rate

We present a physics-based model that accurately predicts the performance of Medtronic's implantable medical device battery lithium/carbon monofluoride (CF$_x$) - silver vanadium oxide (SVO) under both low-rate background monitoring and high-rate pulsing currents. The distinct properties multiple active materials are reflected by parameterizing their thermodynamics, kinetics, mass transport separately. Diffusion limitations Li$^+$ in SVO used to explain cell voltage transient behavior during pulse post-pulse relaxation. also introduce change cathode electronic conductivity, Li metal anode surface morphology, film resistance buildup capture evolution internal throughout multi-year electrical tests. share our insights on how redistribution process between can restore capability hybrid electrode, allow CF$_x$ indirectly contribute capacity release pulsing, affect operation protocols design principles batteries with other electrodes. discuss additional complexities porous electrode parameterization electrochemical characterization techniques due parallel reactions solid diffusion pathways across materials. hope models implemented Hybrid Multiphase Porous Electrode Theory (Hybrid-MPET) framework complement future experimental research accelerate development multi-active material electrodes targeted performance.