Mathematical Modeling of Aging Mechanisms in Lithium-Ion Batteries

Abstract

The performance of a battery cell degrades over time due to the different aging mechanisms. These unavoidable processes ultimately turn the particular cells into non-useful battery pack components. It is better to estimate the online degradation status of cells during the charging/discharging phenomenon. However, the constant aging parameters are difficult to determine due to the non-ideal behavior of cell chemistry. Understanding aging characteristics over time is vital for the smooth operation of the battery pack and its life. However, it is a misconception to associate cell failure with normal aging alone. The impurities in materials during manufacturing, uncontrolled processes during assembling, or design faults could be causes of battery failure. The mentioned causes of battery failure are out of the scope of this portion of the book. The main aim of the chapter is to understand, model, and monitor normal aging processes, which can serve as a building block for optimized batteries’ algorithms for safe operation. In this chapter, a brief discussion of different aging mechanisms is presented. The governing equations/assumptions of all the processes/mechanisms and their subsequent models are also discussed.