Behavioral modeling and analysis of galvanic devices

摘要

A new hybrid modeling approach was developed for galvanic devices including batteries and fuel cells. The new approach reduces the complexity of the First Principles method and adds a physical basis to the empirical methods. The resulting general model includes all the processes that affect the terminal behavior of the galvanic devices. The first step of the new model development was to build a physics-based structure or framework that reflects the important physiochemical processes and mechanisms of a galvanic device. Thermodynamics, electrode kinetics, mass transport and electrode interfacial structure of an electrochemical cell were considered and included in the model. Each process of the cell is represented by a clearly-defined and familiar electrical component, resulting in an equivalent circuit model for the galvanic device. The second step was to develop a parameter identification procedure that correlates the device response data to the parameters of the components in the model. This procedure eliminates the need for hard-to-find data on the electrochemical properties of the cell and specific device design parameters. Thus, the model is chemistry and structure independent. Implementation issues of the new modeling approach were presented. The validity of the new model over a wide range of operating conditions was verified with experimental data from actual devices.