Effect of Electrode Thickness and Operating Temperature on Electrochemical Performance of Li-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) have emerged of late as the most popular high-energy storage devices with a variety of uses, including electric vehicles and cell phones. Due to structural stability, low cost, and longer cycle life compared to other LIB systems, the lithium titanate and lithium manganese oxide (LTO-LMO) pair has gained wide interest. Researchers have investigated how the electrode thickness affects the LIBs performance. However, there is still limited understanding of how the LIB cell performance depends on the operating temperature. In this paper, a 1D electrochemical model has been developed to predict the LTO-LMO cell performance under different operating conditions using the COMSOL multiphysics simulation software. The model predictions are successfully validated with published experimental studies. Further, a parametric study is performed by varying the electrode thickness and operating temperature. The results established that for low discharge rates (C rates), higher thickness results in increased cell discharge capacity, but for higher C rates, this is not true due to poor electrode utilization. This study also effectively optimizes the cell cathode and anode thickness using response surface methodology based ANOVA to maximize discharge capacity. This study could prove very useful in the future development of LIBs.