A Flexible Framework for Modeling Multiple Solid, Liquid and Gaseous Phases in Batteries and Fuel Cells

Multi-phase management is crucial for performance and durability of electrochemical cells such as batteries and fuel cells. In this \npaper we present a generic framework for describing the two-dimensional spatiotemporal evolution of gaseous, liquid and solid \nphases, as well as their interdependence with interfacial (electro-)chemistry and microstructure in a continuum description. The \nmodeling domain consists of up to seven layers (current collectors, channels, electrodes, separator/membrane), each of which can \nconsist of an arbitrary number of bulk phases (gas, liquid, solid) and connecting interfaces (two-phase or multi-phase boundaries). \nBulk and interfacial chemistry is described using global or elementary kinetic reactions. Multi-phase management is coupled to \nchemistry and to mass and charge transport within bulk phases. The functionality and flexibility of this framework is demonstrated \nusing four application areas in the context of post-lithium-ion batteries and fuel cells, that is, lithium-sulfur (Li-S) cells, lithiumoxygen \n(Li-O) cells, solid oxide fuel cells (SOFC) and polymer electrolyte membrane fuel cells (PEFC). The results are compared \nto models available in literature and properties of the generic framework are discussed.