Analytical Approach for Evaluation of Lithium-Ion Battery Cells

A new method for evaluation of battery cells containing porous thin-layer electrodes is developed. For this purpose, a typical concept of chemical reaction engineering to classify reactors by dimensionless characteristic values is used. Therefore, the system of equations describing the porous electrodes in a battery cell is transferred to dimensionless notation and corresponding dimensionless properties are developed. The required kinetic data are measured with the help of electrochemical test cells. A complete set of parameters for the description of the lithium-ion battery is determined and the characteristic properties for the chosen example are calculated and analyzed. Finally, the performance of the anode and cathode using lithium manganese oxide and surface-modified graphite as active materials is compared with the aid of the newly developed dimensionless parameters.