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A model is proposed and used to parameterize the surface-temperature distribution and electrical response for A123 20 Ah LiFePO4 prismatic cells. The cell interior is described by a porous-electrode charge-transport model based on Newman-Tobias theory, which is coupled to a local heat balance. Simulation output depends on only a few observable dimensionless quantities, allowing parameter estimation via iterative optimization schemes that directly compare computed results with experimental voltage and surface-temperature measurements.Despite the neglect of mass-transport limitations within Newman-Tobias theory, the model accurately predicts the dynamic terminal voltage, as well as the minimum, maximum, and surface-averaged temperature on the cell exterior. The electrochemical and thermal properties extracted from square-wave cycling data with various excitation amplitudes (2 C and 4 C) and short charge/discharge periods (50 s and 100 s) compare well with literature values, showing that it is possible to infer internal material properties by fitting external measurements. The temperature dependence of parameters has clear signatures in the observed voltage.

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