Lithium Plating at the Cell Edge Induced by Anode Overhang during Cycling in Lithium-Ion Batteries: Part I. Modeling and Mechanism

The anode overhang is usually cited to prevent lithium plating at the cell edges of lithium-ion batteries. Still, numerous reports in the literature show lithium plating at the cell edge, which is typically referred to as edge plating. Edge plating is often attributed to inhomogeneous lithium distribution, thermal gradients, or pressure-dependent effects. This work presents an easy-to-implement two-dimensional electrochemical model demonstrating inhomogeneous lithiation induced by the anode overhang, which can explain experimentally observed edge plating. First, the mechanism of inhomogeneous lithiation due to the anode overhang is explained in detail. Then, a parameter study on charge protocol and geometric cell properties is presented, and the implications for cell applications are analyzed. Finally, the findings are discussed and put into a broader perspective of cell design, manufacturing, and fast charging application. In Part II of this work, the simulation is validated experimentally using multi-reference electrode single-layer pouch cells.