A Novel AC Method for Determining the Threshold Plating Current in Li-Ion Batteries via Electrical Measurements

This study presents a novel method for determining the threshold plating current in Lithium-ion batteries using electrical measurements. Lithium plating is the primary cause of battery degradation and poses potential safety risks. Understanding the factors that lead to Lithium plating is crucial for ensuring the safe operation of Lithium-ion battery systems. Conventional methods for identifying the charging current that leads to plating are time-consuming, involve multiple cycles, and are inaccurate. In this study, a novel method was proposed and tested on commercial Panasonic and Sony Lithium-ion battery cells under various charging currents and low temperature conditions. In the alternative current (AC) method, a pair of battery cells is used. A sinusoidal current is applied to the test cell, simultaneously the reference cell undergoes a relaxation phase after the charging phase. To accurately determine the threshold plating current, differential voltage analysis (DVA) is employed. DVA identifies the voltage plateau observed in the discharge phase, when plating occurs. Our method was validated using the iterative approach, which involves gradually adjusting the charging current to determine the point at which plating begins. The results showed that the AC method achieved accurate results, with deviations between the methods being less than 100 mA. The key findings include the robustness of the method across different cell types and temperatures, highlighting its potential for broader applications. Our method offers a faster, simpler, and non-destructive way to determine the threshold plating current, thereby optimizing the battery performance and safety.