Crosstalk Reactions Induce Positive- and Negative-Electrode Resistance Increments in Li[Li1/3Ti5/3]O4/LiNi1/2Mn3/2O4 Cells

Abstract

With the rapid utilization of lithium-ion batteries (LIBs) in various applications, including automobiles, battery-lifetime extension has become an important issue. A major cause of capacity fading in batteries is the increase in the positive- and negative-electrode resistance, mainly due to the formation of highly resistive electrode films. Previous studies indicate that crosstalk reactions significantly influence the resistance-increase mechanism. Although previous publications confirm that the rate of positive-electrode resistance-increase is greatly affected by the negative-electrode potential, the quantitative relationship between the crosstalk reaction and cell-resistance increment remains unexplained. In this study, potentiostatic charge tests were performed on Li[Li1/3Ti5/3]O4/LiNi1/2Mn3/2O4 cells by varying the charging voltage. Although the number of side reactions increased on increasing the charging voltage, the increase in cell resistance remained almost same; the Li[Li1/3Ti5/3]O4 and LiNi1/2Mn3/2O4 electrode resistances increased significantly after potentiostatic charging. To explain the resistance-increase behavior of the cell, a phenomenological model incorporating the crosstalk reaction was proposed. Subsequently, this model was used to calculate the increase in cell resistance. The simulation results were consistent with the experimental results, indicating that the model could be used to quantitatively predict the increase in cell resistance.