Blend Electrodes in Lithium‐Ion Batteries: Investigation of Inhomogeneities Using a Spatially Resolved Transmission Line Model

Blend electrodes are used in lithium‐ion batteries to increase the performance by combining two active materials, such as silicon (Si) or silicon oxide (SiOx) and graphite (Gr), for the negative electrode. In‐depth knowledge of the complex interactions between the materials is essential to understand how inhomogeneities and local peaks of the intercalation current arise and how they can be prevented. This work presents a spatially resolved transmission line model developed to describe the electrochemical behavior of blend electrodes. Parameterization and model validation are carried out for a Gr/SiOx anode. Simulation results are used to investigate inhomogeneities in local states during lithiation at different C‐rates. A special focus is put on stress indicators as precursors for accelerated ageing like local material‐specific C‐rates and spatial gradients of the degree of lithiation. Thus, the modeling approach is a tool for both the description of the properties of blend electrodes and for simulation‐based balancing of the active materials’ capacities within blend electrodes.