Author(s): Thomas, Karen E.; Newman, John; Darling, Robert M. | Abstract: Early work on modeling lithium batteries, performed prior to the ready availability of high-speed digital computers, used simplified models neglecting kinetic or cencentration effects, assuming constant properties, or neglecting the separator, in order to obtain a close approximation to battery behavior within the limits of computational power available at the time. Today's computers can easily simulate the entire cell sandwich model, and simply present the model in the best form developed to date in section 3, followed by considerations of special situations which are not essential to the basic modeling framework. Simplifying cases which have contributed to our understanding of the lithium battery are presented in section 5. Finally, we discuss applications of modeling, such as interpreting experimental data and optimizing geometric parameters.