Thermodynamic Analysis of Coal Derived Graphite for Battery Anodes Using the Multi-Species, Multi-Reaction Model

Abstract

Automotive manufacturers are working to improve individual cell and overall pack design by increasing their performance, durability, and range, while reducing cost. As the time from initial design to manufacture of electric vehicles is decrease, design work that used to rely solely on testing needs to be supplemented or replaced by virtual methods. As electrochemical engineers drive battery and system design using model-based methods, models that have a basis in physics, rather than purely empirical representations, are necessary to allow engineers to drive design through a linkage to manufacturing methods. In this study, we apply the Multi-Species, Multi-Reaction model as popularized by Verbrugge and Baker to an electrochemical system comprised of a counter electrode and a working electrode synthesized from graphite derived from coal.To do this, the open circuit voltage of the coal derived graphite and a standard commercially available graphite was quantified. Linear sweep voltammetry provided insight into the shift in electrochemical reactions based on the structure and composition of the coal derived graphite. This then allows the MSMR model to capture the thermodynamic performance of the coal derived graphite, and sheds further insight into the performance compared to the standard commercially available system. Commentary on the thermodynamic differences between the systems will be provided and additional analytical techniques may be used to rationalize differences in performance.