Experimental study and empirical modeling of lithium ion battery lifetime

The capacity loss of lithium ion batteries during charge/discharge cycles is one of the important parameters in the evaluation of these kind of batteries, so that battery lifetime is defined as the number of charge/discharge cycles until the battery capacity reaches to 70% of its initial capacity. Therefore, it is important to have a simple mathematical model which can easily predict capacity loss of lithium ion batteries with acceptable accuracy. In this study, capacity loss were measured experimentally for first 10 cycles of Samsung commercial lithium ion battery at three temperatures of 25, 35 and 45oC. Further, a semi empirical model has been introduced including power law concept for temperature and the square root of cycle number to predict the lithium-ion battery lifetime or capacity loss. The parameters of the model have been obtained based on square of error of the prediction of experimental capacity using Levenberg -Marquardt algorithm. Using this model, maximum charge/discharge cycle of the battry is calculated acceptably with less than 15% of error.